061012 comparison for 2006 codes

ASCE 7-05 compared to ASCE 7-02 Summary below is based on SEI summary of proposed changes.

ASCE 7 Section Comments

1 General

2 Combinations of Loads

3 Added Section 3.2 and Table 3-1 on Soil and Hydrostatic pressure from Section 5.

4 Live Loads

5 Flood Loads

6 Wind

The changes listed in this comparison are not exhaustive, but reflect items that might be of interest to the structural component industry. Comments are indicated by blue text. Significant changes are indicated by red text.

Table 1-1, revised to recognize the “semi-essential” nature of certain quasi-public facilities, whose failure/ unavailability can cause a significant economic loss and/or a large-scale disruption of day-to-day civilian life.Added definitions for Toxic and Highly Toxic Materials to provide clarity on the determination of the distinction between hazardous and extremely hazardous materials.

Additional exception at Section 2.3.2 :(3) In combinations (2), (4), and (5), the companion load S shall be taken as the balanced snow load, as defined in sections 7.3 and 7.4.

Additional exception at Section 2.4:Exception: In combinations (4) and (6), the companion load S shall be taken as either the flat roof snow load (pf) or the sloped roof snow load (ps).

Dead Loads, Soil Loads, and Hydrostatic Pressure

1. Added needed definitions (balcony and deck) and relocate existing definitions into a single definitions section.2. Editorially clarified gymnasium and hospital in Table 4.13. Organized roof loads into a single area within Table 4.14. Added a specific provision for partition loads – Section 4.2.25. Clarified provision 4.3 on concentrated loads – relocated roof truss provision to Table 4.16. Removed the 20 lb/ft requirement for guardrails and handrails in one- and two-family dwellings, leaving only the concentrated load requirements. Under limited circumstances, it allows guardrails and handrails in factory, industrial, and storage occupancies to be designed for the same loads as one- and two-family dwellings.7. Clarified distribution of roof live loads in 4.68. Clarified provisions by which uniform roof live loads are permitted to be reduced (4.8 and 4.9)

1. Editorially relocated soil and hydrostatic provisions to Section 3.2. Clarified definition of Coastal A Zone.

1. Clarified and expand the application of Method 1 – Simplified Method2. Excluded torsionally sensitive buildings from using Method 1.3. Modified the pressures for parapets and clarify their application for low-slope roofs4. Added a definition for eave height and clarify footnote 8 of Figure 6-10.5. Added provisions for freestanding walls and solid signs6. Added provisions for canopies and free roofs7. Clarified exposure categories for main wind force resisting systems and components and cladding8. Provided objective and enforceable criteria for using climatic data to determine the basic wind speed in special wind regions and other non-hurricane-prone regions.9. Clarified that the basic wind speed obtained from regional climatic data may be less that Figure 6-110. Modified provisions for rooftop equipment11. Expanded required protection of glazing in wind borne debris regions; clarify that it’s required when loads are determined using Method 3; and update referenced standards

7 Snow

8 Rain no changes

9 Earthquake

10 Ice

11A Quality Assurance Provisions Moved from Appendix A.9.3. Other Supplementary Requirements removed.

11B Existing Building Provisions New

App. A Serviceability Considerations Unchanged

1. Corrected Terrain Category provisions to reflect elimination of Exposure Category A in Section 6 during 2002 revision cycle (Table 7-2).2. For rain on snow surcharge, properly related the application of surcharge to both width and slope of the roof (Section 7.10).3. Revised the lower bound slope for gable roof snow drift (Sections, 7.6.1, 7.3.4, and 7.5.1).4. Provided an equivalent uniform snow load to accommodate gable roof drift loads for residential structures (Section 7.6.1).5. Clarified definition of height of balanced snow load (Section 7.1) and remove unused definition.6. Revised provisions for gable roof drift loads for wide roofs (Section 7.6.1 and Figure 7-5)

many revisions and much reorganization.EQ-7: Wood1. Updated reference standards2. Revised seismic design coefficients

1. Revised uniform ice thickness maps and add new map for Alaska and revise Section 10.4.2 accordingly.2. Added provision 10.5.5 for wind on ice-covered guys and cables

Summary below is based on SEI summary of proposed changes.

Comments Impact

Added Section 3.2 and Table 3-1 on Soil and Hydrostatic pressure from Section 5. no impact.

See details at Live Load page

no impact.

See details at Wind Load page

The changes listed in this comparison are not exhaustive, but reflect items that might be of interest to the structural component industry. Significant changes are indicated by red text.

Table 1-1, revised to recognize the “semi-essential” nature of certain quasi-public facilities, whose failure/ unavailability can cause a significant economic loss and/or a large-scale disruption of day-to-day civilian life.Added definitions for Toxic and Highly Toxic Materials to provide clarity on the determination of the distinction between hazardous and extremely hazardous materials.

Not significant to component design. Categories in Table 1-1 remain essentially the same.

Additional exception at Section 2.3.2 :(3) In combinations (2), (4), and (5), the companion load S shall be taken as the balanced snow load, as defined in

Additional exception at Section 2.4:Exception: In combinations (4) and (6), the companion load S shall be taken as either the flat roof snow load (pf) or the

Can have an impact on wood component design load cases.


1. Editorially relocated soil and hydrostatic provisions to Section 3.2. Clarified definition of Coastal A Zone.


See details at snow load page

no changes no impact.

no impact.

Moved from Appendix A.9.3. Other Supplementary Requirements removed. no impact.New no impact.Unchanged no impact.

1. Corrected Terrain Category provisions to reflect elimination of Exposure Category A in Section 6 during 2002 revision

2. For rain on snow surcharge, properly related the application of surcharge to both width and slope of the roof (Section

3. Revised the lower bound slope for gable roof snow drift (Sections, 7.6.1, 7.3.4, and 7.5.1).4. Provided an equivalent uniform snow load to accommodate gable roof drift loads for residential structures (Section

5. Clarified definition of height of balanced snow load (Section 7.1) and remove unused definition.6. Revised provisions for gable roof drift loads for wide roofs (Section 7.6.1 and Figure 7-5)

many revisions and much reorganization.

1. Updated reference standards2. Revised seismic design coefficients

no direct impact on trusses. May have impact on wood design in general. See AF&PA SDPWS.

1. Revised uniform ice thickness maps and add new map for Alaska and revise Section 10.4.2 accordingly.2. Added provision 10.5.5 for wind on ice-covered guys and cables

Impact

no impact.

See details at Live Load page

no impact.

See details at Wind Load page

Not significant to component design. Categories in Table 1-1 remain essentially the same.

Can have an impact on wood component design load

See details at snow load page

no impact.

no impact.

no impact.no impact.no impact.

no direct impact on trusses. May have impact on wood design in general. See AF&PA SDPWS.

LIVE Loads

Summary

Partition Loads:

Partial Loading

Concentrated Loads

Roof Loads added to Table 4.1

Live Load Reductions:

Significant changes are indicated by red text.

7-05

Partition Loads:

Partial Loading

See footnote 8 to Table 4-1


4.2.2 Provision for Partitions In office buildings or other buildings where partitions will be erected or rearranged,provision for partition weight shall be made, whether or not partitions are shown on the plans, unless the specified live load exceeds 80 lb/ft2 (3.83 kN/m2). Partition load shall not be less than 15 psf.

Exception: A partition live load is not required where the minimum specified live load exceeds 80 psf (3.83 kN/m2).

C4.2.2 Provision for PartitionsThe 2005 version of the standard provides the minimum partition load for the first time, although the requirement for theload has been included for many years. Historically a value of 20 psf has been required by building codes. This load,however, has sometimes been treated as a dead load.If we assume that a normal partition would be a stud wall with ½ inch gypsum board on each side (8 psf per Table C3-1),10 feet high, we end up with a wall load on the floor of 80 lb/ft. If the partitions are spaced throughout the floor areacreating rooms on a grid 10 feet on center, which would be an extremely dense spacing over a whole bay, the averagedistributed load would be 16 psf. A design value of 15 psf is judged to be reasonable in that the partitions are not likelyto be spaced this closely over large areas. Designers should consider a larger design load for partitions if a high densityof partitions is anticipated.

4.6 Partial Loading The full intensity of the appropriately reduced live load applied only to a portion of a structure or member shall be accounted for if it produces a more unfavorable effect than the same intensity applied over the full structure or member. Roof live loads are to be distributed as specified in Table 4-1.

C4.6 Partial Loading. It is intended that the full intensity of the appropriately reduced live load over portions of thestructure or member be considered, as well as a live load of the same intensity over the full length of the structure ormember.Partial-length loads on a simple beam or truss will produce higher shear on a portion of the span than a full-lengthload. `Checkerboard′ loadings on multistoried, multipanel bents will produce higher positive moments than fullloads, while loads on either side of a support will produce greater negative moments. Loads on the half span ofarches and domes or on the two central quarters can be critical.For roofs, all probable load patterns should be considered uniform roof live loads that are reduced to less than 20lb/ft2 (0.96 kN/m2) using Section 4.9.1. Where the full value of the roof live load (Lr) is used without reduction, it isconsidered that there is a low probability that the roof live load created by maintenance workers, equipment, andmaterial could occur in a patterned arrangement. Where a uniform roof live load is caused by an occupancy, partialor pattern loading should be considered regardless of the magnitude of the uniform load. Cantilevers must not relyon a possible live load on the anchor span for equilibrium.

Concentrated Loads

Roof Loads added to Table 4.1

4.3 Concentrated Loads Floors, roofs, and other similar surfaces shall be designed to support safely the uniformlydistributed live loads prescribed in 4.2 or the concentrated load, in pounds or kilonewtons (kN), given in Table 4-1,whichever produces the greater load effects. Unless otherwise specified, the indicated concentration shall beassumed to be uniformly distributed over an area 2.5 feet (762 mm) square [6.25 ft2 (0.58 m2)] and shall be locatedso as to produce the maximum load effects in the structural members.

Same as existing first paragraph of 4.3 except for the addition of roofs. Second paragraph moved to footnote in Table 4-1.

C4.3 Concentrated LoadsThe provision, in Table 4-1, regarding concentrated loads supported by roof trusses or other primary roof members is intended to provide for a common situation for which specific requirements are generally lacking.Primary roof members are main structural members such as roof trusses, girders, and frames, which are exposed to awork floor below, where the failure of such a primary member resulting from their use as attachment points forlifting or hoisting loads could lead to the collapse of the roof. Single roof purlins or rafters (where there are multiplesuch members placed side by side at some reasonably small center-to-center spacing, and where the failure of asingle such member would not lead to the collapse of the roof), are not considered to be primary roof members.

During the public comment period, WTCA suggested the following change:

Primary roof members are main structural members such as roof trusses, girders, and frames, which are exposed to a work floor below, where the failure of such a primary member resulting from their use as attachment points for lifting or hoisting loads could lead to the collapse of the roof. Single roof purlins, trusses or rafters (where there are multiple such members placed side by side at some reasonably small center-to-center spacing, less than 48 inches, and where the failure of a single such member would not lead to the collapse of the roof), are not considered to be primary roof members.

The increase from 200 lb to 300 lb was based upon the existing 300 lb loading on ladder rungs.

Live Load Reductions:

(8) Where uniform roof live loads are reduced to less than 20 lb/ft2 (0.96 kN/m2) in accordance with Section 4.9.1 and are applied to the design of structural members arranged so as to create continuity, the reduced roof live load shall be applied to adjacent spans or to alternate spans, whichever produces the greatest unfavorable effect.(9) Roofs used for other special purposes shall be designed for appropriate loads as approved by the authority having jurisdiction.

The base roof live load still equals 20 psf (and it still can be reduced per Section 8.9). Footnote 8 reflects language similar to that for Partial Loading at Section 4.6.

The language on concentrated loads from Section 4.3, second paragraph, has been incorporated into Table 4-with some significant and undocumented changes: The 200 lb concentrated load has been increased to 300 lb And is applied to "all roof surfaces subject to maintenance workers."

The addition of 'roofs' to the provisions of Section 4.3 on the application of concentrated loads as a separate consideration from the application of uniform live load would apply and indicate that the consideration of the concentrated load is non-concurrent with other uniformly distributed live loads and would be applied over a 2.5 feet square area. However,since "roof surfaces' is not defined, this might be interpreted to apply to both TC & BC surfaces.

4.8 Reduction in Live Loads Except for roof uniform live loads, all other minimum uniformly distributed live loads, Lo in Table 4-1, may be reduced according to the following provisions.

4.9 Reduction in Roof Live Loads: The minimum uniformly distributed roof live loads, L0 in Table 4-1, are permitted to be reduced according to the following provisions.

Clarifies that there are different methods for reducing general Live Loads and specific Roof Live Loads. This is not a change, only a clarification.

7-02

1. Added needed definitions (balcony and deck) and relocate existing definitions into a single definitions section.

6. Removed the 20 lb/ft requirement for guardrails and handrails in one- and two-family dwellings, leaving only the concentrated load requirements. Under limited circumstances, it allows guardrails and handrails in factory, industrial, and storage occupancies to be

4.2.2 Provision for Partitions In office buildings or other buildings where partitions will be erected or rearranged,provision for partition weight shall be made, whether or not partitions are shown on the plans, unless the specified live load

Exception: A partition live load is not required where the minimum specified live load exceeds 80 psf (3.83 kN/m2).

4.2.2 Provision for Partitions. In office buildings or otherbuildings where partitions will be erected or rearranged,provision for partition weight shall be made, whether ornot partitions are shown on the plans, unless the specifiedlive load exceeds 80 lb/ft2 (3.83 kN/m2).

The 2005 version of the standard provides the minimum partition load for the first time, although the requirement for theload has been included for many years. Historically a value of 20 psf has been required by building codes. This load,

If we assume that a normal partition would be a stud wall with ½ inch gypsum board on each side (8 psf per Table C3-1),10 feet high, we end up with a wall load on the floor of 80 lb/ft. If the partitions are spaced throughout the floor areacreating rooms on a grid 10 feet on center, which would be an extremely dense spacing over a whole bay, the averagedistributed load would be 16 psf. A design value of 15 psf is judged to be reasonable in that the partitions are not likelyto be spaced this closely over large areas. Designers should consider a larger design load for partitions if a high density

4.6 Partial Loading The full intensity of the appropriately reduced live load applied only to a portion of a structure or member shall be accounted for if it produces a more unfavorable effect than the same intensity applied over the full structure or

SECTION 4.6 PARTIAL LOADINGThe full intensity of the appropriately reduced live loadapplied only to a portion of a structure or member shallbe accounted for if it produces a more unfavorable effectthan the same intensity applied over the full structureor member.

C4.6 Partial Loading. It is intended that the full intensity of the appropriately reduced live load over portions of thestructure or member be considered, as well as a live load of the same intensity over the full length of the structure or

Partial-length loads on a simple beam or truss will produce higher shear on a portion of the span than a full-lengthload. `Checkerboard′ loadings on multistoried, multipanel bents will produce higher positive moments than fullloads, while loads on either side of a support will produce greater negative moments. Loads on the half span of

For roofs, all probable load patterns should be considered uniform roof live loads that are reduced to less than 20Where the full value of the roof live load (Lr) is used without reduction, it is

considered that there is a low probability that the roof live load created by maintenance workers, equipment, andmaterial could occur in a patterned arrangement. Where a uniform roof live load is caused by an occupancy, partial

Cantilevers must not rely

distributed live loads prescribed in 4.2 or the concentrated load, in pounds or kilonewtons (kN), given in Table 4-1,whichever produces the greater load effects. Unless otherwise specified, the indicated concentration shall beassumed to be uniformly distributed over an area 2.5 feet (762 mm) square [6.25 ft2 (0.58 m2)] and shall be located

SECTION 4.3 CONCENTRATED LOADSFloors and other similar surfaces shall be designed to supportsafely the uniformly distributed live loads prescribedin Section 4.2 or the concentrated load, in pounds or kilonewtons(kN), given in Table 4-1, whichever producesthe greater load effects. Unless otherwise specified, theindicated concentration shall be assumed to be uniformlydistributed over an area 2.5 ft square (762 mm square)[6.25 ft2 (0.58 m2)] and shall be located so as to producethe maximum load effects in the structural members.Any single panel point of the lower chord of exposedroof trusses or any point along the primary structuralmembers supporting roofs over manufacturing, commercialstorage and warehousing, and commercial garage floorsshall be capable of carrying safely a suspended concentratedload of not less than 2000 lb (pound-force) (8.90 kN)in addition to dead load. For all other occupancies, aload of 200 lb (0.89 kN) shall be used instead of 2000 lb(8.90 kN).

The provision, in Table 4-1, regarding concentrated loads supported by roof trusses or other primary roof members

Primary roof members are main structural members such as roof trusses, girders, and frames, which are exposed to awork floor below, where the failure of such a primary member resulting from their use as attachment points forlifting or hoisting loads could lead to the collapse of the roof. Single roof purlins or rafters (where there are multiplesuch members placed side by side at some reasonably small center-to-center spacing, and where the failure of asingle such member would not lead to the collapse of the roof), are not considered to be primary roof members.

SECTION C4.3 CONCENTRATED LOADSC4.3.1 Accessible Roof-Supporting Members. The provisionregarding concentrated loads supported by rooftrusses or other primary roof members is intended to providefor a common situation for which specific requirementsare generally lacking.

Primary roof members are main structural members such as roof trusses, girders, and frames, which are exposed to a work floor below, where the failure of such a primary member resulting from their use as attachment points for lifting or hoisting loads could lead to the collapse of the roof. Single roof purlins, trusses or rafters (where there are multiple such members

and where the failure of a single such member would not lead to the collapse of the roof), are not considered to be primary roof members.

Section 4.3 (second paragraph)Any single panel point of the lower chord of exposedroof trusses or any point along the primary structuralmembers supporting roofs over manufacturing, commercialstorage and warehousing, and commercial garage floorsshall be capable of carrying safely a suspended concentratedload of not less than 2000 lb (pound-force) (8.90 kN)in addition to dead load. For all other occupancies, aload of 200 lb (0.89 kN) shall be used instead of 2000 lb(8.90 kN).

Section 4.3 (second paragraph)Any single panel point of the lower chord of exposedroof trusses or any point along the primary structuralmembers supporting roofs over manufacturing, commercialstorage and warehousing, and commercial garage floorsshall be capable of carrying safely a suspended concentratedload of not less than 2000 lb (pound-force) (8.90 kN)in addition to dead load. For all other occupancies, aload of 200 lb (0.89 kN) shall be used instead of 2000 lb(8.90 kN).

(8) Where uniform roof live loads are reduced to less than 20 lb/ft2 (0.96 kN/m2) in accordance with Section 4.9.1 and are applied to the design of structural members arranged so as to create continuity, the reduced roof live load shall be applied to

(9) Roofs used for other special purposes shall be designed for appropriate loads as approved by the authority having

in Table 4-1, may be reduced The minimum uniformly distributed live loads, Lo inTable 4-1, may be reduced according to the followingprovisions.

in Table 4-1, are permitted to be reduced according to the following

Wind Loads

Summary

Definitions:

Simplified Procedure:

Analytic Procedure:

Commentary on Exposure (image examples)

Wind Borne Debris

Parapets

Open Buildings with Monoslope, Pitched or Troughed Roofs

Rooftop Structures

Figures and Tables (see details below)

Details:

Wind LoadsSignificant changes are indicated by red text.

7-05

Simplified Procedure:

Revised, but not detailed herem since typically not used for truss design.

Analytic Procedure:


EAVE HEIGHT: The distance from the ground surface adjacent to the building to the roof eave line at a particularwall. If the height of the eave varies along the wall, the average height shall be used.

C6.1.4.1 Minimum Design Wind Loading on MWFRS. This section specifies a minimum wind load to beapplied horizontally on the entire vertical projection of the building as shown in Figure C6-0. This load case is to beapplied as a separate load case in addition to the normal load cases specified in other portions of Section 6.

C6.5.4In the ASCE 7-02 standard, the Kz expressions are unchanged from ASCE 7-98. However, the possibility ofinterpolating between the standard exposures using a rational method is recognized in the present edition. Onerational method is provided below. (see commentary for further details)

Commentary on Exposure (image examples)

6.5.6 Exposure. For each wind direction considered, the upwind exposure category shall be based on ground surface roughness that is determined from natural topography, vegetation, and constructed facilities.

C6.5.65. The required fetch upwind of a tall building has been increased from 10 to 20 building heights. This is a morerealistic distance based on the calculation method in C6.5.6.4 for the fetch length required for the planetaryboundary layer to change after a change in surface roughness.

It should be noted that for Exposure B the tabulated values of Kz in Section 6.5.6.4 correspond to the lower limit ofthe range of z0, whereas for Exposures C and D they correspond to the typical value of z0. The reason for thedifference in Exposure B is that this category of terrain, which is applicable to suburban areas, often contains openpatches such as highways, parking lots and playing fields. These cause local increases in the wind speeds at theiredges. By using an exposure coefficient corresponding to the lower limit of z0 , rather than the typical value, someallowance is made for this. The alternative would be to introduce a number of exceptions to use of Exposure B insuburban areas, which would add an undesirable level of complexity.

6.5.6.3 Exposure CategoriesExposure B: Exposure B shall apply where the ground surface roughness condition, as defined by SurfaceRoughness B, prevails in the upwind direction for a distance of at least 2600 ft. (792 m) or ten times the height ofthe building, whichever is greater.Exception: For buildings whose mean roof height is less than or equal to 30 ft , the upwind distance may bereduced to 1500 feet (457 m).Exposure C: Exposure C shall apply for all cases where exposures B or D do not apply.Exposure D: Exposure D shall apply where the ground surface roughness, as defined by Surface Roughness D,prevails in the upwind direction for a distance greater than 5000 ft. (1524 m) or 20 times the building height,whichever is greater. Exposure D shall extend into downwind areas of Surface Roughness B or C for a distance of600 feet (200 m) or 20 times the height of the building, whichever is greater.For a site located in the transition zone between exposure categories, the category resulting in the largest wind forces shall be used. Exception: An intermediate exposure between the above categories is permitted in a transition zoneprovided that it is determined by a rational analysis method defined in the recognized literature.

Wind Borne Debris

Revise caption on upper photo.SUBURBAN RESIDENTIAL AREA WITH MOSTLY SINGLE-FAMILY DWELLINGS. LOW RISESTRUCTURES, LESS THAN 30 FT (9.1 M) HIGH, IN THE CENTER OF THE PHOTOGRAPH HAVE SITESDESIGNATED AS EXPOSURE B WITH SURFACE ROUGHNESS CATEGORY B TERRAIN AROUND THESITE FOR A DISTANCE GREATER THAN 1500 FT (457 m), IN ANY WIND DIRECTION.

Revise caption on lower photo.URBAN AREA WITH NUMEROUS CLOSELY SPACED OBSTRUCTIONS HAVING SIZE OF SINGLEFAMILY DWELLINGS OR LARGER. FOR ALL STRUCTURES SHOWN, TERRAIN REPRESENTATIVE OFSURFACE ROUGHNESS CATEGORY B EXTENDS MORE THAN TWENTY TIMES THE HEIGHT OFTHE STRUCTURE OR 2600FT (792 M), WHICH EVER IS GREATER, IN THE UPWIND DIRECTION.

Revise caption on upper photo.Exposure B: Structures in the foreground are located in Exposure B. Structures in the center top of the photographadjacent to the clearing to the left, which is greater than approximately 656 ft (200 m) in length, are located inExposure C when wind comes from the left over the clearing. (See Figure C6-5)

6.5.6.5 Exposure Category for Components And Cladding Components and cladding design pressures for allbuildings and other structures shall be based on the exposure resulting in the highest wind loads for any direction atthe site.

6.5.6.6 Velocity Pressure Exposure Coefficient Based on the exposure category determined in Section 6.5.6.3, avelocity pressure exposure coefficient Kz or Kh, as applicable, shall be determined from Table 6-3. For a site locatedin a transition zone between exposure categories, i.e. near to a change in ground surface roughness, intermediatevalues of Kz or Kh , between those shown in Table 6-3, are permitted, provided that they are determined by a rationalanalysis method defined in the recognized literature.

6.5.9.3 Wind Borne Debris. Glazing in buildings located in wind borne debris regions shall be protected with animpact resistant covering or be impact resistant glazing according to the requirements specified in ASTM E 1886and E 1996 (see Ref. 6-1 and 6-1 in Section 6.7) or other approved test methods and performance criteria. Thelevels of impact resistance shall be a function of Missile Levels and Wind Zones specified in ASTM E 1886 and E1996 (see Ref. 6-2 in Section 6.7).Exceptions:1. Glazing in Category II, III, or IV buildings located over 60 feet (18.3 m) above the ground and over 30 feet (9.2m) above aggregate surface roofs located within 1500 ft. (458 m) of the building shall be permitted to beunprotected.2. Glazing in Category I buildings shall be permitted to be unprotected.

C6.5.9Attention is made to 6.5.9.3, which requires glazing in Category II, III and IV buildings in wind borne debrisregions to be protected with an impact resistant covering or be impact resistant. The option of unprotected glazingwas eliminated for most buildings in this edition of the standard in order to reduce the amount of wind and waterdamage to buildings during design wind storm events.

Open Buildings with Monoslope, Pitched or Troughed Roofs

C6.5.11.5 Parapets Prior to the 2002 edition of the standard, no provisions for the design of parapets had beenincluded due to the lack of direct research. In the 2002 edition of this standard, a rational method was added basedon the committee’s collective experience, intuition, and judgment. In the 2005 edition, the parapet provisions havebeen updated as a result of research performed at the University of Western Ontario [C6-xxx] and at ConcordiaUniversity [C6-yyy and C6-zzz].Wind pressures on a parapet are a combination of wall and roof pressures, depending on the location of the parapet,and the direction of the wind, see Figure C6-9. A windward parapet will experience the positive wall pressure on itsfront surface (exterior side of the building) and the negative roof edge zone pressure on its back surface (roof side).This behavior is based on the concept that the zone of suction caused by the wind stream separation at the roof eave moves up to the top of the parapet when one is present. Thus the same suction which acts on the roof edge will also act on the back of the parapet. (see Commentary for additional details)

6.5.13 Design Wind Loads on Open Buildings with Monoslope, Pitched or Troughed Roofs6.5.13.1 General6.5.13.1.1 Sign Convention Plus and minus signs signify pressure acting towards and away from the top surface ofthe roof, respectively.6.5.13.1.2 Critical Load Condition Net pressure coefficients CN include contributions from top and bottomsurfaces. All load cases shown for each roof angle shall be investigated.6.5.13.2 Main Wind Force Resisting Systems The net design pressure for the main wind force resisting systemsof monoslope, pitched or troughed roofs shall be determined by the following equation:P = qhGCN (Eq. 6-25)whereqh = velocity pressure evaluated at mean roof height h using the exposure as defined in Section 6.5.6.3 that resultsin the highest wind loads for any wind direction at the siteG = gust effect factor from 6.5.8CN = net pressure coefficient determined from Figures 6-18A through 6-18DFor free roofs with angle of plane of roof from horizontal θ less than or equal to five degrees containing fasciapanels, the fascia panel shall be considered an inverted parapet. The contribution of loads on the fascia to theMWFRS loads shall be calculated using Section 6.5.12.2.4 with qp equal to qh.6.5.13.3 Component and Cladding Elements The net design wind pressure for component and cladding elementsof monoslope, pitched and troughed roofs shall be determined by the following equation:P = qhGCN (Eq. 6-26)whereqh = velocity pressure evaluated at mean roof height h using the exposure as defined in Section 6.5.6.3 that resultsin the highest wind loads for any wind direction at the siteG = gust effect factor from 6.5.8CN = net pressure coefficient determined from Figures 6-19A through 6-19C

Rooftop Structures

Figures and Tables (see details below)Figure 6-1, 1a, 1b, 1c Basic Wind SpeedFigure 6-2 MWFRS Method 1 Walls & Roofs - Enclosed Buildings

C6.5.13 Design Wind Loads on Open Buildings with Monoslope, Pitched or Troughed Roofs:New Figures 6-18 and 6-19 are presented for wind loads on main wind force resisting systems and components andcladding of open buildings with roofs as shown, respectively. This work is based on the Australian StandardAS1170.2-2000, Part 2: Wind Actions, with modifications to the Main Wind Force Resisting System pressurecoefficients based on recent studies [C6.XX and C6.YY].The roof wind loading on Open Building Roofs is highly dependent upon whether goods or materials are storedunder the roof and restrict the wind flow. Restricting the flow can introduce substantial upward acting pressures onthe bottom surface of the roof, thus increasing the resultant uplift load on the roof. Figures 6-18 and 6-19 offer thedesigner two options. Option 1 “Clear Wind Flow” implies little (less than 50%) or no portion of the cross sectionbelow the roof is blocked. Option 2 “Obstructed Wind Flow” implies that a significant portion (more than 75% istypically referenced in the literature) of the cross section is blocked by goods or materials below the roof. Clearly,values would change from one set of coefficients to the other following some sort of smooth but as yet unknownrelationship. In developing the provisions included in this standard, the 50 percent blockage value was selected forOption 1, Clear Flow with the expectation that it represents a somewhat conservative transition. If the designer isnot clear about usage of the space below the roof or if the usage could change to restrict free air flow, then designloads for both options should be used.In determining loads on component and cladding elements for open building roofs using Figure 6-19, it is importantfor the designer to note that the net pressure coefficient CN is based on contributions from the top and bottomsurfaces of the roof. This implies that the element receives load from both surfaces. Such would not be the case ifthe surface below the roof was separated structurally from the top roof surface. In this case, the pressure coefficientshould be separated for the effect of top and bottom pressures, or conservatively, each surface could be designedusing the CN value from Figure 6-19.

6.5.14 Design Wind Loads on Solid Freestanding Walls and Solid Signs. The design wind force for solidfreestanding walls and solid signs shall be determined by the following formula:F = qh G Cf As (lb) (N) (Eq. 6-27)qh = the velocity pressure evaluated at height h (defined in Figure 6-20) usingexposure defined in Section 6.5.6.4.1;G = gust effect factor from section 6.5.8;Cf = net force coefficients from Figure 6-20;As = the gross area of the solid freestanding wall or solid sign, in ft2 (m2);6.5.15 Design Wind Loads on Other Structures The design wind force for other structures shall be determined bythe following formula:F = q G Cf Af (lb) (N) (Eq. 6-28)whereqz = velocity pressure evaluated at height z of the centroid of area Af using exposure defined in Section6.5.6.3;G = gust effect factor from Section 6.5.8;Cf = net force coefficients from Figure 6-18, Figure 6-19 and Figures 6-21 through 6-22; andAf = projected area normal to the wind except where Cf is specified for the actual surface area, ft2 (m2).

6.5.15.1 Rooftop Structures and Equipment for buildings with h ≤ 60 ft (18.3 m). The force on rooftopstructures and equipment with Af less than (0.1 B h) located on buildings with h ≤ 60 ft (18.3 m) shall bedetermined from Eq. 6-25, increased by a factor of 1.9. The factor shall be permitted to be reduced linearly from 1.9to 1.0 as the value of Af is increased from (0.1 B h) to (B h).

Figure 6-3 C&C Method 1 Walls & Roofs - Enclosed Buildings, h ≤ 60 ftFigure 6-4 Topographic FactorFigure 6-5 MWFRS/C&C Method 2 Internal Pressure CoefficientFigure 6-6 MWFRS Method 2 All Heights External Pressure Coefficients - Walls & RoofsFigure 6-7 MWFRS Method 2 All Heights External Pressure Coefficients - Domed RoofsFigure 6-8 MWFRS/C&C Method 2 All Heights External Pressure Coefficients - Arched RoofsFigure 6-9 MWFRS Method 2 All Heights - Design Load CasesFigure 6-10 MWFRS Method 2 External Pressure Coefficients - Low-rise Walls & RoofsFigure 6-11A - 11D C&C Method 2 External Pressure Coefficients - Walls/Gable/Hip RoofsFigure 6-12 C&C Method 2 External Pressure Coefficients - Stepped RoofsFigure 6-13 C&C Method 2 External Pressure Coefficients - Multispan Gable RoofsFigure 6-14A & 6-14B C&C Method 2 External Pressure Coefficients - Monoslope RoofsFigure 6-15 C&C Method 2 External Pressure Coefficients - Sawtooth RoofsFigure 6-16 C&C Method 2 External Pressure Coefficients - Domed RoofsFigure 6-17 C&C Method 2 External Pressure Coefficients - Walls and Roofs h ≤ 60 ftFigure 6-18 MWFRS Method 2 Force Coefficients All Heights - Monoslope RoofsFigure 6-19 C&C Method 2 Force Coefficients - Chimneys, Tanks, Rooftop Equipment, etc.Figure 6-20 Other Structures Method 2 Solid Freestanding Walls & Solid Signs

Figure 6-21 Other Structures Method 2 Open Signs & Lattice FrameworksFigure 6-22 Other Structures Method 2 Trussed TowersTables 6-1 - 6-4

Revise Figure 6-3 to add values for 105, 125, and 145 psf and change the heading:

Revise Figure 6-2 to add values for 105, 125, and 145 psf and change the heading:Revise footnotes:1. Pressures shown are applied to the horizontal and vertical projections, for exposure B, at h=30 ft (9.1m), forI=1.0, and Kzt = 1.0. Adjust to other conditions using Equation 6-1.4. Load cases 1 and 2 represent the positive and negative internal pressure cases respectively. Only Load Case 1 isrequired for 0° ≤ θ ≤ 25°. Both cases must be checked for 25° < θ ≤ 45°. Load case 2 at 25° is provided onlyfor interpolation between 25° to 30°.

Revise Figure 6-10 as follows:Notes:8. The roof pressure coefficient GCpf, when negative in Zone 2 or 2E, shall be applied in Zone 2/2E for a distancefrom the edge of roof equal to 0.5 times the horizontal dimension of the building parallel to the direction of theMWFRS being designed or 2.5h times the eave height at the windward wall, whichever is less; the remainder ofZone 2/2E extending to the ridge line shall use the pressure coefficient GCpf for Zone 3/3E.

Revise Figure 6-11B as follows:Notes:5. If a parapet equal to or higher than 3 ft (0.9m) is provided around the perimeter of the roof with θ ≤ 7°, thenegative values of GCp in Zone 3 shall be treated as equal to those for Zone 2 and positive values of GCp in Zones2 and 3 shall be set equal to those for wall Zones 4 and 5 respectively in Figure 6-11A.

Replace Figure 6-18 with Figures 6-18A through Figure 6-18D (main wind force resistingsystems), add Figure 6-19A through Figure 6-19C (components and cladding), and renumberFigures 6-19 through 6-22 to 6-20 through 6-23, respectively. Change references to currentFigures 6-19 and 6-22 accordingly

Replace Figure 6-20 with new Figure 6-20.

Replace the existing Table C6-4 with the following:Replace existing Table C6-5 with the following:Replace existing Table C6-6 with the following:Add Tables C6-ZZ, C6-YY, and C6-XXa as follows:

Commentary on Figures 6-8, 6-18, 6-19, 6-21 and 6-22ASCE 7-05 requires the use of Figure 6-19 [? 6-22] for the determination of the wind force on small structures andequipment located on a rooftop. Because of the small size of the structures in comparison to the building, it isexpected that the wind force will be higher than predicted by Eq. 6-25 due to higher correlation of pressures acrossthe structure surface, higher turbulence on the building roof, and accelerated wind speed on the roof. There is now avery limited amount of research to provide better guidance for the increased force [C6-XYZ]. Based on thisresearch, the force of Eq. 6–25 should be increased by a factor of 1.9 for units with area less than (0.1 B h). Because the multiplier is expected to approach 1.0 as Af approaches that of the building (B h), a linear interpolation is included as a way to avoid a step function in load if the designer wants to treat other sizes. The research only treated one value of Af (0.04 B h).The research also showed high uplifts on the top of rooftop air conditioning units, although the net uplift on the unitswas not measured. The consensus of the Committee is that uplift forces may be a significant fraction of thehorizontal force; hence uplift load should also be considered by the designer.

7-02

New

New

new

New

8. Provided objective and enforceable criteria for using climatic data to determine the basic wind speed in special wind regions and

11. Expanded required protection of glazing in wind borne debris regions; clarify that it’s required when loads are determined using

The distance from the ground surface adjacent to the building to the roof eave line at a particular

C6.1.4.1 Minimum Design Wind Loading on MWFRS. This section specifies a minimum wind load to beThis load case is to be

applied as a separate load case in addition to the normal load cases specified in other portions of Section 6.

expressions are unchanged from ASCE 7-98. However, the possibility ofinterpolating between the standard exposures using a rational method is recognized in the present edition. One

New

6.5.6 Exposure. For each wind direction considered, the upwind exposure category shall be based on ground surface

6.5.6 Exposure. For each wind direction considered, anexposure category that adequately reflects the characteristicsof ground roughness and surface irregularities shall bedetermined for the site at which the building or structureis to be constructed. Account shall be taken of variationsin ground surface roughness that arises from naturaltopography and vegetation as well as constructed features.

5. The required fetch upwind of a tall building has been increased from 10 to 20 building heights. This is a morerealistic distance based on the calculation method in C6.5.6.4 for the fetch length required for the planetary

in Section 6.5.6.4 correspond to the lower limit ofthe range of z0, whereas for Exposures C and D they correspond to the typical value of z0. The reason for thedifference in Exposure B is that this category of terrain, which is applicable to suburban areas, often contains openpatches such as highways, parking lots and playing fields. These cause local increases in the wind speeds at theiredges. By using an exposure coefficient corresponding to the lower limit of z0 , rather than the typical value, someallowance is made for this. The alternative would be to introduce a number of exceptions to use of Exposure B in

Exposure B: Exposure B shall apply where the ground surface roughness condition, as defined by Surfacetimes the height of

Exception: For buildings whose mean roof height is less than or equal to 30 ft , the upwind distance may be

Exposure D: Exposure D shall apply where the ground surface roughness, as defined by Surface Roughness D, the building height,

of Surface Roughness B or C for a distance of

For a site located in the transition zone between exposure categories, the category resulting in the largest wind forces shall be used. Exception: An intermediate exposure between the above categories is permitted in a transition zone

6.5.6.3 Exposure Categories.Exposure B: Exposure B shall apply where the groundsurface roughness condition, as defined by SurfaceRoughness B, prevails in the upwind direction fora distance of at least 2630 ft (800 m) or 10 timesthe height of the building, whichever is greater.Exception: For buildings whose mean roofheight is less than or equal to 30 ft (9.1 m),the upwind distance may be reduced to1500 ft (457 m).Exposure C: Exposure C shall apply for all caseswhere exposures B or D do not apply.Exposure D: Exposure D shall apply where theground surface roughness, as defined by surfaceroughness D, prevails in the upwind direction for adistance at least 5000 ft (1524 m) or 10 times thebuilding height, whichever is greater. Exposure Dshall extend inland from the shoreline for a distanceof 660 ft (200 m) or 10 times the height of thebuilding, whichever is greater.For a site located in the transition zone between exposurecategories, the category resulting in the largestwind forces shall be used. Exception: An intermediateexposure between the above categories ispermitted in a transition zone provided that it isdetermined by a rational analysis method definedin the recognized literature.

, IN THE CENTER OF THE PHOTOGRAPH HAVE SITESDESIGNATED AS EXPOSURE B WITH SURFACE ROUGHNESS CATEGORY B TERRAIN AROUND THE

EXPOSURE B (pg 279)SUBURBAN RESIDENTIAL AREA WITH MOSTLY SINGLE-FAMILY DWELLINGS. STRUCTURES IN THE CENTER OF THE PHOTOGRAPH HAVE SITES DESIGNATED AS EXPOSURE B WITH SURFACE ROUGHNESS CATEGORY B TERRAIN AROUND THE SITE FOR A DISTANCE GREATER THAN 1500 FT OR TEN TIMES THE HEIGHT OF THE STRUCTURE, WHICHEVER IS GREATER, IN ANY WIND DIRECTION.

URBAN AREA WITH NUMEROUS CLOSELY SPACED OBSTRUCTIONS HAVING SIZE OF SINGLEFAMILY DWELLINGS OR LARGER. FOR ALL STRUCTURES SHOWN, TERRAIN REPRESENTATIVE OF

TWENTY TIMES THE HEIGHT OF, WHICH EVER IS GREATER, IN THE UPWIND DIRECTION.

EXPOSURE B (pg 279)URBAN AREA WITH NUMEROUS CLOSELY SPACED OBSTRUCTIONS HAVING THE SIZE OF SINGLE-FAMILY DWELLINGS OR LARGER. FOR ALL STRUCTURES SHOWN, TERRAIN REPRESENTATIVE OF SURFACE ROUGHNESS CATEGORY B EXTENDS MORE THAN TEN TIMES THE HEIGHT OF THE STRUCTURE OR 800 M, WHICHEVER IS GREATER, IN THE UPWIND DIRECTION.

Exposure B: Structures in the foreground are located in Exposure B. Structures in the center top of the photographin length, are located in

EXPOSURE B (pg 280)STRUCTURES IN THE FOREGROUND ARE LOCATED IN EXPOSURE B. STRUCTURES IN THE CENTER TOP OF THE PHOTOGRAPHADJACENT TO THE CLEARING TO THE LEFT, WHICH IS GREATER THAN 200 M IN LENGTH, ARE LOCATED IN EXPOSURE C WHENWIND COMES FROM THE LEFT OVER THE CLEARING (SEE FIGURE C6-5)

6.5.6.5 Exposure Category for Components And Cladding Components and cladding design pressures for allbuildings and other structures shall be based on the exposure resulting in the highest wind loads for any direction at

6.5.6.5 Exposure Category for Components and Cladding.6.5.6.5.1 Buildings with Mean Roof Height h LessThan or Equal to 60 ft (18 m). Components andcladding for buildings with a mean roof height h of60 ft (18 m) or less shall be designed using a velocitypressure qh based on the exposure resulting in thehighest wind loads for any wind direction at the site.6.5.6.5.2 Buildings with Mean Roof Height hGreater Than 60 ft (18 m) and Other Structures.Components and cladding for buildings with a meanroof height h in excess of 60 ft (18 m) and forother structures shall be designed using the exposureresulting in the highest wind loads for any winddirection at the site.

6.5.6.6 Velocity Pressure Exposure Coefficient Based on the exposure category determined in Section 6.5.6.3, a, as applicable, shall be determined from Table 6-3. For a site located

in a transition zone between exposure categories, i.e. near to a change in ground surface roughness, intermediatevalues of Kz or Kh , between those shown in Table 6-3, are permitted, provided that they are determined by a rational

6.5.6.6 Velocity Pressure Exposure Coefficient. Basedon the exposure category determined in Section 6.5.6.3,a velocity pressure exposure coefficient Kz or Kh, asapplicable, shall be determined from Table 6-3.

6.5.9.3 Wind Borne Debris. Glazing in buildings located in wind borne debris regions shall be protected with animpact resistant covering or be impact resistant glazing according to the requirements specified in ASTM E 1886

or other approved test methods and performance criteria. Thelevels of impact resistance shall be a function of Missile Levels and Wind Zones specified in ASTM E 1886 and E

1. Glazing in Category II, III, or IV buildings located over 60 feet (18.3 m) above the ground and over 30 feet (9.2m) above aggregate surface roofs located within 1500 ft. (458 m) of the building shall be permitted to be

6.5.9.3 Wind-Borne Debris. Glazing in buildings classifiedas Category II, III, or IV (Note 1) located inwind-borne debris regions shall be protected with animpact-resistant covering or be impact-resistant glazingaccording to the requirements (Note 2) specifiedin Ref. 6-1 and Ref. 6-2 referenced therein or otherapproved test methods and performance criteria.Notes:1. In Category II, III, or IV buildings, glazing locatedover 60 ft (18.3 m) above the ground and over30 ft (9.2 m) above aggregate surface roof debrislocated within 1500 ft (458 m) of the buildingshall be permitted to be unprotected.Exceptions: In Category II and III buildings(other than health care, jail, and detention facilities,power generating and other public utilityfacilities), unprotected glazing shall be permitted,provided that unprotected glazing thatreceives positive external pressure is assumedto be an opening in determining the buildings’enclosure classification.2. The levels of impact resistance shall be a functionof Missile Levels and Wind Zones specified inRef. 6-2.

Attention is made to 6.5.9.3, which requires glazing in Category II, III and IV buildings in wind borne debrisThe option of unprotected glazing

was eliminated for most buildings in this edition of the standard in order to reduce the amount of wind and water

Attention is made to Section 6.5.9.3, which requiresglazing in Category II, III, and IV buildings in wind-bornedebris regions to be protected with an impact-resistant coveringor be impact resistant. For Category II and III buildings(other than health care, jails and detention facilities,and power-generating and other public utility facilities), anexception allows unprotected glazing, provided the glazingis assumed to be openings in determining the building’sexposure classification. The option of unprotected glazingfor Category III health care, jails and detention facilities,power-generating and other public utility facilities,and Category IV buildings was eliminated in this editionof the Standard because it is important for these facilitiesto remain operational during and after design windstormevents.

C6.5.11.5 Parapets Prior to the 2002 edition of the standard, no provisions for the design of parapets had beenincluded due to the lack of direct research. In the 2002 edition of this standard, a rational method was added basedon the committee’s collective experience, intuition, and judgment. In the 2005 edition, the parapet provisions havebeen updated as a result of research performed at the University of Western Ontario [C6-xxx] and at Concordia

Wind pressures on a parapet are a combination of wall and roof pressures, depending on the location of the parapet,and the direction of the wind, see Figure C6-9. A windward parapet will experience the positive wall pressure on itsfront surface (exterior side of the building) and the negative roof edge zone pressure on its back surface (roof side).This behavior is based on the concept that the zone of suction caused by the wind stream separation at the roof eave moves up to the top of the parapet when one is present. Thus the same suction which acts on the roof edge will also act

C6.5.11.5 Parapets. Previous versions of the Standardhave had no provisions for the design of parapets, althoughthe companion “Guide” [C6-87] has shown a methodology.The problem has been the lack of direct research in thisarea on which to base provisions. Research has yet to be performed, but the Committee thought that a rational method based on its collective experience, intuition, and judgment was needed, considering the large number of buildings with parapets. (see Commentary for additional details)

6.5.13.1.1 Sign Convention Plus and minus signs signify pressure acting towards and away from the top surface of

6.5.13.1.2 Critical Load Condition Net pressure coefficients CN include contributions from top and bottom

6.5.13.2 Main Wind Force Resisting Systems The net design pressure for the main wind force resisting systems

qh = velocity pressure evaluated at mean roof height h using the exposure as defined in Section 6.5.6.3 that results

For free roofs with angle of plane of roof from horizontal θ less than or equal to five degrees containing fasciapanels, the fascia panel shall be considered an inverted parapet. The contribution of loads on the fascia to the

6.5.13.3 Component and Cladding Elements The net design wind pressure for component and cladding elements

= velocity pressure evaluated at mean roof height h using the exposure as defined in Section 6.5.6.3 that results

6.5.13 Design Wind Loads on Open Buildings andOther Structures. The design wind force for open buildingsand other structures shall be determined by the followingformula:F = qzGCfAf (lb)(N) (Eq. 6-25)whereqz = velocity pressure evaluated at height z of thecentroid of area Af using exposure defined inSection 6.5.6.3;G = gust effect factor from Section 6.5.8;Cf = net force coefficients from Figure 6-18 through6-22; andAf = projected area normal to the wind except where Cfis specified for the actual surface area, ft2 (m2).

None

New

New

NOTES

unchangedAdded additional wind speeds and revised footnotes 1 & 4

New Figures 6-18 and 6-19 are presented for wind loads on main wind force resisting systems and components andcladding of open buildings with roofs as shown, respectively. This work is based on the Australian StandardAS1170.2-2000, Part 2: Wind Actions, with modifications to the Main Wind Force Resisting System pressure

The roof wind loading on Open Building Roofs is highly dependent upon whether goods or materials are storedunder the roof and restrict the wind flow. Restricting the flow can introduce substantial upward acting pressures onthe bottom surface of the roof, thus increasing the resultant uplift load on the roof. Figures 6-18 and 6-19 offer thedesigner two options. Option 1 “Clear Wind Flow” implies little (less than 50%) or no portion of the cross sectionbelow the roof is blocked. Option 2 “Obstructed Wind Flow” implies that a significant portion (more than 75% istypically referenced in the literature) of the cross section is blocked by goods or materials below the roof. Clearly,values would change from one set of coefficients to the other following some sort of smooth but as yet unknownrelationship. In developing the provisions included in this standard, the 50 percent blockage value was selected forOption 1, Clear Flow with the expectation that it represents a somewhat conservative transition. If the designer isnot clear about usage of the space below the roof or if the usage could change to restrict free air flow, then design

In determining loads on component and cladding elements for open building roofs using Figure 6-19, it is importantfor the designer to note that the net pressure coefficient CN is based on contributions from the top and bottomsurfaces of the roof. This implies that the element receives load from both surfaces. Such would not be the case ifthe surface below the roof was separated structurally from the top roof surface. In this case, the pressure coefficientshould be separated for the effect of top and bottom pressures, or conservatively, each surface could be designed

6.5.14 Design Wind Loads on Solid Freestanding Walls and Solid Signs. The design wind force for solid

6.5.15 Design Wind Loads on Other Structures The design wind force for other structures shall be determined by

qz = velocity pressure evaluated at height z of the centroid of area Af using exposure defined in Section

Af = projected area normal to the wind except where Cf is specified for the actual surface area, ft2 (m2).

6.5.15.1 Rooftop Structures and Equipment for buildings with h ≤ 60 ft (18.3 m). The force on rooftop less than (0.1 B h) located on buildings with h ≤ 60 ft (18.3 m) shall be

determined from Eq. 6-25, increased by a factor of 1.9. The factor shall be permitted to be reduced linearly from 1.9

Wall zone 5 500 deleted. Added additional wind speedsunchangedunchangedunchangedunchangedunchangedunchanged

unchangedunchangedunchangedunchangedunchangedunchangedReplaced with 6-18A - 6-18DReplaced with 6-19A - 6-18CReplaced

unchanged

Revise Figure 6-3 to add values for 105, 125, and 145 psf and change the heading:

See Standard for details

unchanged, except for expansion of footnote 8 to include 2Eunchanged, except for revision to Figure 6-11B, footnote 5

unchanged, Moved to 6-22, Inserted - chimneys, tanks, rooftop equipmentunchanged, Moved to 6-23

1. Pressures shown are applied to the horizontal and vertical projections, for exposure B, at h=30 ft (9.1m), for

represent the positive and negative internal pressure cases respectively. Only Load Case 1 ismust be checked for 25° < θ ≤ 45°. Load case 2 at 25° is provided only

8. The roof pressure coefficient GCpf, when negative in Zone 2 or 2E, shall be applied in Zone 2/2E for a distancefrom the edge of roof equal to 0.5 times the horizontal dimension of the building parallel to the direction of theMWFRS being designed or 2.5h times the eave height at the windward wall, whichever is less; the remainder of

5. If a parapet equal to or higher than 3 ft (0.9m) is provided around the perimeter of the roof with θ ≤ 7°, thenegative values of GCp in Zone 3 shall be treated as equal to those for Zone 2 and positive values of GCp in Zones

Replace Figure 6-20 with new Figure 6-20. See Standard for details

Replace the existing Table C6-4 with the following: See Commentary for detailsReplace existing Table C6-5 with the following: See Commentary for detailsReplace existing Table C6-6 with the following: See Commentary for detailsAdd Tables C6-ZZ, C6-YY, and C6-XXa as follows: See Commentary for details

for the determination of the wind force on small structures andequipment located on a rooftop. Because of the small size of the structures in comparison to the building, it isexpected that the wind force will be higher than predicted by Eq. 6-25 due to higher correlation of pressures acrossthe structure surface, higher turbulence on the building roof, and accelerated wind speed on the roof. There is now avery limited amount of research to provide better guidance for the increased force [C6-XYZ]. Based on thisresearch, the force of Eq. 6–25 should be increased by a factor of 1.9 for units with area less than (0.1 B h). Because the multiplier is expected to approach 1.0 as Af approaches that of the building (B h), a linear interpolation is included as a way to avoid a step function in load if the designer wants to treat other sizes. The research only treated one value of

The research also showed high uplifts on the top of rooftop air conditioning units, although the net uplift on the unitswas not measured. The consensus of the Committee is that uplift forces may be a significant fraction of the

ASCE 7-02 has been modified to explicitly require theuse of Figure 6-19 for the determination of the wind loadon equipment located on a rooftop. Because there is a lackof research to provide better guidance for loads on rooftopequipment, this change was made based on the consensusopinion of the Committee. Because of the relatively smallsize of the equipment it is believed that the gust effect factorwill be higher than 0.85; however, no research presentlyexists upon which to base a recommendation. Use of a gusteffect factor of 1.1 or higher should be considered based onobservations in a recent wind-tunnel study reported to theTask Committee on Wind Loads. Eq. 6-4 may be used as aguide in determining the gust effect factor. Caution shouldalso be exercised in the positioning of the equipment onthe roof. If rooftop equipment is located, either in wholeor in part, in the higher pressure zones near a roof’s edge,consideration should be given to increasing the wind load.

Snow Loads

Summary

7.1 Symbols & Notations

Low-Slope Roofs

Continuous Beam Systems

Unbalanced Snow

Rain-on-Snow

Examples:

Snow LoadsSignificant changes are indicated by red text.

7-05

7.1 Symbols & Notations

Low-Slope Roofs

Continuous Beam Systems

Unbalanced Snow

1. Corrected Terrain Category provisions to reflect elimination of Exposure Category A in Section 6 during 2002 revision cycle (Table 7-2).2. For rain on snow surcharge, properly related the application of surcharge to both width and slope of the roof (Section 7.10).3. Revised the lower bound slope for gable roof snow drift (Sections, 7.6.1, 7.3.4, and 7.5.1).4. Provided an equivalent uniform snow load to accommodate gable roof drift loads for residential structures (Section 7.6.1).5. Clarified definition of height of balanced snow load (Section 7.1) and remove unused definition.6. Revised provisions for gable roof drift loads for wide roofs (Section 7.6.1 and Figure 7-5)

Additional exception at Section 2.4:Exception: In combinations (4) and (6), the companion load S shall be taken as either the flat roof snow load (p f) or the sloped roof snow load (ps).

Since there is some discussion that the effects of wind in combination with snow may be related in roof truss design, this new statement may require further consideration.

hb = height of balanced snow load determined by dividing ps by γ, in ft (m)

7.3.4 Minimum Values of pf for Low-Slope Roofs Minimum values of pf shall apply to monoslope roofs with slopes less than 15 degrees, hip, and gable roofs with slopes less than the larger of 2.38 degrees (1/2 on 12) and (70/W) + 0.5 with W in ft (in SI: 21.3/W + 0.5, with W in m), and curved roofs where the vertical angle from the eaves to the crown is less than 10 degrees.

7.5.1 Continuous Beam Systems Continuous beam systems shall be investigated for the effects of the three loadings shown in Figure 7-4:Case 1: Full balanced snow load on either exterior span and half the balanced snow load on all other spans.Case 2: Half the balanced snow load on either exterior span and full balanced snow load on all other spans.Case 3: All possible combinations of full balanced snow load on any two adjacent spans and half the balanced snow load on all other spans. For this case there will be (n-1) possible combinations where n equals the number of spans in the continuous beam system. If a cantilever is present in any of the above cases, it shall be considered to be a span.Partial load provisions need not be applied to structural members that span perpendicular to the ridgeline in gable roofs with slopes greater than the larger of 2.38° (1/2 on 12) and 70/W + 0.5 with W in ft (in SI: 21.3/W + 0.5, with W in m).

7.6.1 Unbalanced Snow Loads for Hip and Gable Roofs For hip and gable roofs with a slope exceeding 70 degrees or with a slope less than 70/W + 0.5 with W in ft (in SI: 21.3/W + 0.5, with W in m) and pg > 20 psf (0.96 kN/m2), unbalanced snow loads are not required to be applied. Roofs with an eave to ridge distance, W, of 20 ft (6.1m) or less, having simply supported prismatic members spanning from ridge to eave shall be designed to resist an unbalanced uniform snow load on the leeward side equal to I pg . For these roofs the windward side shall be unloaded. For all other gable roofs, the unbalanced load shall consist of 0.3 ps on the windward side, ps on the leeward side plus a rectangular surcharge with magnitude hdγS.5 and horizontal extent from the ridge 8S.5hd /3 where hd is the drift height from Figure 7-9 with lu equal to the eave to ridge distance for the windward portion of the roof, W. Balanced and unbalanced loading diagrams are presented in Figure 7.5.

Rain-on-Snow

C7.6.1 Unbalanced Snow Loads on Hip and Gable Roofs The expected shape of a gable roof drift is nominally atriangle located close to the ridgeline. Recent research suggests that the size of this nominally triangular gable roof drift is comparable to a leeward roof step drift with the same fetch. For certain simple structural systems, for example wood or light gage roof rafter systems with either a ridge board or a supporting ridge beam, with small eave to ridge distances, the drift is represented by a uniform load of Ipg from eave to ridge. The Ipg load results in larger maximum rafter moment and shear than the expected triangular distribution plus balanced load. For all other gable roofs, the drift is represented by a rectangular distribution located adjacent to the ridge. The location of the centriod for the rectangular distribution is identical to that for the expected triangular distribution. The intensity is the average of that for the expected triangular distribution.

7.10 Rain-on-Snow Surcharge Load For locations where pg is 20 lb/ft2 (0.96 kN/m2) or less, but not zero, all roofs with slopes (in degrees) less than W/50 with W in ft. (in SI: W/15.2 with W in m) shall have a 5 lb/ft2 (0.24 kN/m2) rain-on-snow surcharge. This rain-on-snow augmented design load applies only to the balanced load case and need not be used in combination with drift, sliding, unbalanced or partial loads.

C7.10 Rain on Snow Surcharge Load The ground snow-load measurements on which this standard is based contain the load effects of light rain on snow. However, since heavy rains percolate down through snowpacks and may drain away, they might not be included in measured values. Where pg is greater than 20 lb/ft2 (0.96 kN/m2), it is assumed that the full rain-on-snow effect has been measured and a separate rain-on-snow surcharge is not needed. The temporary roof load contributed by a heavy rain may be significant. Its magnitude will depend on the duration and intensity of the design rainstorm, the drainage characteristics of the snow on the roof, the geometry of the roof, and the type of drainage provided. Loads associated with rain on snow are discussed in [C7-54], [C7-55] , and [C7-58].

Calculated rain-on-snow loading in Reference [C7.58] show that the surcharge is an increasing function of eave to ridge distance and a decreasing function of roof slope. That is, rain-on-snow surcharges are largest for wide, low sloped roofs. The minimum slope reflects that functional relationship.

The following example illustrates the evaluation of the rain-on-snow surcharge. Consider a monoslope roof with slope of 1/4 on 12 and a width of 100 feet with Ce = 1.0, Ct = 1.1, I = 1.2 and pg = 15 psf (0.72 kN/m2). Since Cs = 1.0 for a slope of 1/4 on 12, ps = 0.7 (1.0)(1.1)(1.0)(1.2)(15) = 14 psf (0.67 kN/m2). Since the roof slope 1.19° is less than 100/50 = 2.0 the 5 psf (0. 24 kN/m2) surcharge is added to ps, resulting in a design load of 19 psf (0.91 kN/m2). Since the slope is less than 15°, the minimum load from 7.34 is Ipg = 1.2 (15) = 18 psf (0.86 kN/m2). Hence the rain on snow modified load controls.

Unbalanced Snow Load: Becayse the roof slope is greater than the larger of 1/2 on 12 (2.38°) and 70/30 +0.5 (2.83°), unbalanced loads must be considered. For pg = 30 psf (1.44 kN/m2) and W = lu = 30 ft (9.14 m), hd = 1.86 ft (0.56 m) from Figure 7-9 and γ = 17.9 pcf (2.80 kN/m3) from Eq. 7-3. For a 8 on 12 roof, S = 1.5 and hence the intensity of the drift surcharge, hdγS.5 , is 27.2 psf (1.31 kN/m2) and its horizontal extent 8S.5hd /3 is 6.1 ft (1.87 m).

7-02

1. Corrected Terrain Category provisions to reflect elimination of Exposure Category A in Section 6 during 2002 revision cycle

2. For rain on snow surcharge, properly related the application of surcharge to both width and slope of the roof (Section 7.10).

4. Provided an equivalent uniform snow load to accommodate gable roof drift loads for residential structures (Section 7.6.1).

Exception: In combinations (4) and (6), the companion load S shall be taken as either the flat roof snow load (p f) or

hb = height of balanced snow load determined by dividing pf or ps by γ , in ft (m)

Minimum values of pf shall apply to monoslope roofs with slopes less than 15 degrees, hip, and gable roofs with (70/W) + 0.5 with W in ft (in SI: 21.3/W + 0.5, with W in

m), and curved roofs where the vertical angle from the eaves to the crown is less than 10 degrees.

7.3.4 Minimum Values of pf for Low-Slope Roofs.Minimum values of pf shall apply to monoslope roofswith slopes less than 15 degrees, hip, and gable roofs withslopes less than or equal to (70/W) + 0.5 with W in ft (inSI: 21.3/W + 0.5, with W in m), and curved roofs wherethe vertical angle from the eaves to the crown is less than10 degrees.

7.5.1 Continuous Beam Systems Continuous beam systems shall be investigated for the effects of the three

Case 1: Full balanced snow load on either exterior span and half the balanced snow load on all other spans.Case 2: Half the balanced snow load on either exterior span and full balanced snow load on all other spans.Case 3: All possible combinations of full balanced snow load on any two adjacent spans and half the balanced snow load on all other spans. For this case there will be (n-1) possible combinations where n equals the number of spans

Partial load provisions need not be applied to structural members that span perpendicular to the ridgeline in gable with W in ft (in SI: 21.3/W + 0.5, with W

7.5.1 Continuous Beam Systems. Continuous beam systemsshall be investigated for the effects of the three loadingsshown in Figure 7-4:Case 1: Full balanced snow load on either exterior spanand half the balanced snow load on all other spans.Case 2: Half the balanced snow load on either exteriorspan and full balanced snow load on all other spans.Case 3: All possible combinations of full balanced snowload on any two adjacent spans and half the balancedsnow load on all other spans. For this case there willbe (n − 1) possible combinations where n equals thenumber of spans in the continuous beam system.If a cantilever is present in any of the above cases, it shallbe considered to be a span.Partial load provisions need not be applied to structuralmembers that span perpendicular to the ridge line in gableroofs with slopes greater than 70/W + 0.5 with W in ft (inSI: 21.3/W + 0.5, with W in m).

For hip and gable roofs with a slope exceeding 70 degrees or with a slope less than 70/W + 0.5 with W in ft (in SI: (0.96 kN/m2), unbalanced snow loads are not required to be applied.

having simply supported prismatic members designed to resist an unbalanced uniform snow load on the leeward side equal

For all other gable roofs, the unbalanced load shall consist of 0.3 ps on the windward side, ps on the leeward side plus a rectangular surcharge with magnitude hdγS.5

u equal to the eave to Balanced and unbalanced loading diagrams are presented in

7.6.1 Unbalanced Snow Loads for Hip and GableRoofs. For hip and gable roofs with a slope exceeding 70◦or with a slope less than 70/W + 0.5 with W in ft (inSI: 21.3/W + 0.5, with W in m), unbalanced snow loadsare not required to be applied. For roofs with an eave toridge distance, W, of 20 ft (6.1 m) or less, the structureshall be designed to resist an unbalanced uniform snowload on the leeward side equal to 1.5ps/Ce. For roofs withW >20 ft (6.1 m), the structure shall be designed to resistan unbalanced uniform snow load on the leeward side equalto 1.2(1 + β/2)ps/Ce with β given by Eq. 7-3.

For the unbalanced situation with W >20 ft (6.1 m), thewindward side shall have a uniform load equal to 0.3ps .Balanced and unbalanced loading diagrams are presentedin Figure 7-5.

C7.6.1 Unbalanced Snow Loads on Hip and Gable Roofs The expected shape of a gable roof drift is nominally atriangle located close to the ridgeline. Recent research suggests that the size of this nominally triangular gable roof drift is comparable to a leeward roof step drift with the same fetch. For certain simple structural systems, for example wood or light gage roof rafter systems with either a ridge board or a supporting ridge beam, with small eave to ridge

load results in larger maximum rafter moment and shear than the expected triangular distribution plus balanced load. For all other gable roofs, the drift is represented by a rectangular distribution located adjacent to the ridge. The location of the centriod for the rectangular distribution is identical to that for the expected triangular distribution. The intensity is the average of that

C7.6.1 Unbalanced Snow Loads on Hip and GableRoofs. The unbalanced uniform snow load on the leewardside was 1.5 ps/Ce and 1.3 ps/Ce in the 1993 and 1995editions of this Standard. In this edition, a 1993 approachis prescribed for roofs with small eave to ridge distancesand the 15 degree cutoff is eliminated. For moderate tolarge roofs, the unbalanced snow load on the leeward sidevaries between 1.5 ps/Ce and 1.8 ps/Ce as a function ofβ. The gable roof drift parameter, β, is proportional to thepercentage of the ground snow load that would drift acrossthe ridge line.The design snow load on the windward side for theunbalanced case, 0.3 ps , is based upon case historiespresented in References [C7-21] and [C7-56]. The lowerlimit of θ = 70/W + 0.5 with W in ft (in SI: 21.3/W + 0.5, with W in meters) is intended to exclude lowsloperoofs, such as membrane roofs, on which significantunbalanced loads have not been observed [C7-57].The provisions of the Standard and this Commentarycorrespond to the case where the gable or hip roof, inplan, is symmetric about the ridgeline, specifically roofsfor which the eave to ridgeline distance, W, is the same forboth sides. For asymmetric roofs, the unbalanced load forthe side with the smaller W is expected to be somewhatlarger as discussed in Reference [C7-56].

) or less, but not zero, all roofs with slopes (in degrees) less than W/50 ) rain-on-snow surcharge. This rain-on-snow

augmented design load applies only to the balanced load case and need not be used in combination with drift,

SECTION 7.10 RAIN-ON-SNOW SURCHARGE LOADFor locations where pg is 20 lb/ft2 (0.96 kN/m2) or less, butnot zero, all roofs with a slope less than 1/2 in./ft (2.38◦),shall have a 5 lb/ft2 (0.24 kN/m2) rain-on-snow surchargeload applied to establish the design snow loads. Where theminimum flat roof design snow load from 7.3.4 exceeds pf

as determined by Eq. 7-1, the rain-on-snow surcharge loadshall be reduced by the difference between these two valueswith a maximum reduction of 5 lb/ft2 (0.24 kN/m2).

C7.10 Rain on Snow Surcharge Load The ground snow-load measurements on which this standard is based contain the load effects of light rain on snow. However, since heavy rains percolate down through snowpacks and may drain

(0.96 kN/m2), it is assumed that the full rain-on-snow effect has been measured and a separate rain-on-snow surcharge is not needed. The temporary roof load contributed by a heavy rain may be significant. Its magnitude will depend on the duration and intensity of the design rainstorm, the drainage characteristics of the snow on the roof, the geometry of the roof, and the type of drainage provided. Loads associated with rain on snow are discussed in [C7-54], [C7-55] , and [C7-58].

Calculated rain-on-snow loading in Reference [C7.58] show that the surcharge is an increasing function of eave to ridge distance and a decreasing function of roof slope. That is, rain-on-snow surcharges are largest for wide, low

SECTION C7.10 RAIN-ON-SNOW SURCHARGE LOADThe ground snow-load measurements on which thisStandard is based contain the load effects of light rain-on-snow. However, since heavy rains percolate down through snowpacks and may drain away, they might notbe included in measured values. Where pg is greaterthan 20 lb/ft2 (0.96 kN/m2), it is assumed that the fullrain-on-snow effect has been measured and a separaterain-on-snow surcharge is not needed. The temporary roofload contributed by a heavy rain may be significant. Itsmagnitude will depend on the duration and intensity of thedesign rainstorm, the drainage characteristics of the snowon the roof, the geometry of the roof, and the type ofdrainage provided. Loads associated with rain-on-snow arediscussed in References [C7-54], [C7-55], and [C7-58].Water tends to remain in snow much longer on relativelyflat roofs than on sloped roofs. Therefore, slope isquite beneficial since it decreases opportunities for drainblockages and for freezing of water in the snow.

The following example illustrates the evaluation of the rain-on-snow surcharge. Consider a monoslope roof with = 15 psf (0.72 kN/m2). Since Cs = 1.0

). Since the roof slope 1.19° is less than , resulting in a design load of 19 psf (0.91 kN/m2). Since

). Hence the rain on

The following example illustrates the evaluation of the rain-on-snow surcharge. For a roof with a 1/4 in./ft (1.19 degree) slope, where pg = 20 lb/ft2 (0.96 kN/m2), pf = 18 lb/ft2 (0.86 kN/m2), and the minimum allowable value of pf is 20 lb/ft2 (0.96 kN/m2), the rain-on-snow surcharge of 5 lb/ft2 (0.24 kN/m2) would be added to the 18 lb/ft2 (0.86 kN/m2) flat roof snow load to generate a design load of 23 lb/ft2 (1.10 kN/m2). This rain-on-snow augmented design load corresponds to a uniform or balanced load case and hence need not be used in combination with drift, sliding, unbalanced, or partial loads.

Unbalanced Snow Load: Becayse the roof slope is greater than the larger of 1/2 on 12 (2.38°) and 70/30 +0.5 = 30 ft (9.14 m), hd = 1.86 ft

) from Eq. 7-3. For a 8 on 12 roof, S = 1.5 and hence the d /3 is 6.1 ft (1.87 m).

IBC changes in both printed and pdf versions are marked for change or deletion.Significant changes are indicated by red text.

IBC Section Comments

Chapter 1 - Admin Few changes, none of significance

Chapter 2 - Definitions Many changes, none of significance.

Chapter 3 - Use and Occupancy Major changes to High-Hazard Group H, minor changes to Group R occupancies.

Chapter 4 - Detailed Requirements Many changes, but none that should have direct significance.

Chapter 5 - Heights & Areas Building designer issues, but should not directly impact SBC design.

Chapter 6 - Types of Construction Building designer issues, but should not directly impact SBC design.

Chapter 7 - Fire Resistance Lots of mostly minor building designer issues, but should not directly impact SBC design.

Chapter 8 - Interior Finishes Many changes, but none that should have direct significance.

Chapter 9 - Fire Protection Systems Building designer issues, but should not directly impact SBC design.

Chapter 10 - MOE Building designer issues, but should not directly impact SBC design.

Chapter 11 - Accessibility Building designer issues, but should not directly impact SBC design.

Chapter 12 - Interior Environment Building designer issues, but should not directly impact SBC design.

Chapter 13 - Energy Efficiency Simply refers to IECC.

Chapter 14 - Exterior Walls Building designer issues, but should not directly impact SBC design.

Chapter 15 - Rooftop assemblies Building designer & installation issues, but should not directly impact SBC design.

Chapter 16 - Structural Design Most significant is removal of provisions included in ASCE 7 and updates to ASCE 7-05.

Chapter 17 - Inspections Significant changes, but none that should directly impact SBC manufacturing or use.

Chapter 18 - Soils & Foundations Not reviewed

Chapter 19 - Concrete Not reviewed

Chapter 20 - Aluminum Not reviewed

Chapter 21 - Masonry Not reviewed

Chapter 22 - Steel Not reviewed

Chapter 23 - Wood Major revisions to 2303.4 Trusses

Chapter 24 - Glass & Glazing Not reviewed

Chapter 25 - Gypsum & Plaster Not reviewed

Chapter 26 - Plastic Not reviewed

Chapter 27 - Electrical Not reviewed

Chapter 28 - Mechanical Not reviewed

Chapter 29 - Plumbing Not reviewed

Chapter 30 - Elevators Not reviewed

Chapter 31 - Special Construction Not reviewed

Chapter 32 - Encroachment Not reviewed

Chapter 33 - Safeguards during Constru Not reviewed

Chapter 34 - Existing Structures Not reviewed

Chapter 35 - Referenced Standards Updates as applicable: ASCE 7-05, NFPA 13-02, NDS-05, SDPWS-05, AISI -04 editions

IBC Summary - This comparison is focused on issues that might relate to structural building components (SBC).

IBC changes in both printed and pdf versions are marked for change or deletion.

Comments Impact

Few changes, none of significance

Many changes, none of significance.

Major changes to High-Hazard Group H, minor changes to Group R occupancies. May impact component manufacturing facilities.Many changes, but none that should have direct significance. Group H occupancies.

Building designer issues, but should not directly impact SBC design.


Lots of mostly minor building designer issues, but should not directly impact SBC design.

Many changes, but none that should have direct significance.





Simply refers to IECC.

Building designer issues, but should not directly impact SBC design. Balconies & projectionsBuilding designer & installation issues, but should not directly impact SBC design. Performance requirements for windMost significant is removal of provisions included in ASCE 7 and updates to ASCE 7-05. See details.Significant changes, but none that should directly impact SBC manufacturing or use. See 1705 Statement of special inspectionsNot reviewed

Not reviewed

Not reviewed

Not reviewed

Not reviewed

Major revisions to 2303.4 Trusses See details.Not reviewed

Not reviewed

Not reviewed

Not reviewed

Not reviewed

Not reviewed

Not reviewed

Not reviewed

Not reviewed

Not reviewed

Not reviewed

Updates as applicable: ASCE 7-05, NFPA 13-02, NDS-05, SDPWS-05, AISI -04 editions

- This comparison is focused on issues that might relate to structural building components (SBC).

Change to definition of wall, load-bearing and nonload-bearing

Sprinkler area modifications. Group H occupancies. Mixed use.

705 Fire Walls, 708 Fire Partitions. General fire protection requirements through out.

Major revisions to 2206 Steed Joists. Removal of most CFS provisions to instead reference standard.

Review for updates of specific standards. Changes are not indicated.

Impact

May impact component manufacturing facilities.Group H occupancies.

Balconies & projectionsPerformance requirements for windSee details.See 1705 Statement of special inspections

See details.

Change to definition of wall, load-bearing and nonload-

Sprinkler area modifications. Group H occupancies.

705 Fire Walls, 708 Fire Partitions. General fire protection requirements through out.

Major revisions to 2206 Steed Joists. Removal of most CFS provisions to instead reference standard.

Review for updates of specific standards. Changes are

IBC Details

SectionChapter 161603

1604.3.6 Table 1604.51604.9 & 101605.21605.31605.3.21607.5Table 1607.1

1607.111608

1609

1611.2

1613

Chapter 232303.4

Table 2304.9.1 2304.1123052305.22306230723082308.1

2308.2

2308.4

2308.9.3

2308.9.3.2Table 2308.10.1

2308.112308.12


IBC-06

Information on Construction Documents Adds flood design data Use of Live load reductions to be provided for each live loadAdds extensively to limits related to deflectionClassification of Buildings - only revised slightly. Importance Factors removed. See ASCE 7.Added Counteracting Structural Actions & Wind & Seismic DetailingLRFD Load Combinatations - revised to ASCE 7-05ASD Load Combinations - revised to ASCE 7-05ASD Alternative Load Combinations - commentary revisedPartition Load reduced from 20 psf to 15 psf per ASCE 7-05

Added 300 lb concentrated roof load consideration. Increased exposed BC concentrated from 200 to 300.Note: IBC is slightly different from IRC for attic loading. IBC requires minimum 10 psf DL (j. iii)

Revised to add footnotes to Residential LL & added Roof Loads. Also modified a few loads and moved Catwalks into its own category with a uniform and concentrated load.

Distribution of Roof loads - editorial. Nothing actually changes.

Revises Earthquake Loading extensively. Review as required.

Snow loads - includes no provisions, references ASCE 7-05. Will require evaluation of ice-dams at roof eaves and new consideration of drift surcharge at gable roofs.

Wind loads - references ASCE 7-05. Exposure evaluation revised to ASCE 7-05. Revises simplified method to reflect ASCE 7-05

1611.2 Ponding instability. For roofs with a slope less than 1/4 inch per foot [1.19 degrees (0.0208 rad)], the design calculations shall include verification of adequate stiffness to preclude progressive deflection in accordance with Section 8.4 of ASCE 7.

Note: revisions to truss section are both an expansion on and a consolidation of two sections in the IBC 2003 (2303.4 & 2308.10.7).

2303.4 Trusses.2303.4.1 Design. Wood trusses shall be designed in accordance with the provisions of this code and accepted engineering practice. Members are permitted to be joined by nails, glue, bolts, timber connectors, metal connector plates or other approved framing devices.

2303.4.1.1 Truss designer. The individual or organization responsible for the design of trusses.2303.4.1.2 Truss design drawings. The written, graphic and pictorial depiction of each individual truss shall be provided to the building official and approved prior to installation. Truss design drawings shall also be provided with the shipment of trusses delivered to the job site. Truss design drawings shall include, at a minimum, the information specified below:

1. Slope or depth, span and spacing;2. Location of joints;3. Required bearing widths;4. Design loads as applicable;5. Top chord live load (including snow loads);6. Top chord dead load;7. Bottom chord live load;8. Bottom chord dead load;9. Concentrated loads and their points of application as applicable;10. Controlling wind and earthquake loads as applicable;11. Adjustments to lumber and metal connector plate design value for conditions of use;12. Each reaction force and direction;13. Metal connector plate type, size, thickness or gage, and the dimensioned location of each metal connector plate except where symmetrically located relative to the joint interface;14. Lumber size, species and grade for each member;15. Connection requirements for:15.1. Truss to truss;15.2. Truss ply to ply; and15.3. Field splices.16. Calculated deflection ratio and maximum vertical and horizontal deflection for live and total load as applicable;17. Maximum axial tensile and compression forces in the truss members; and18. Required permanent individual truss member bracing and method per Section 2303.4.1.5, unless a specific truss member permanent bracing plan for the roof or floor structural system is provided by a registered design professional.

Where required by one of the following, each individual truss design drawing shall bear the seal and signatureof the truss designer:1. Registered design professional; or2. Building official; or3. Statutes of the jurisdiction in which the project is to be constructed.Exceptions:1. When a cover sheet/truss index sheet combined into a single cover sheet is attached to the set of truss design drawings for the project, the single sheet/truss index sheet is the only documentthat needs to be signed and sealed within the truss submittal package. 2. When a cover sheet and a truss index sheet are separately provided and attached to the set of truss design drawings for the project, both the cover sheet and the truss index sheet are the only documents that need to be signed and sealed within the truss submittal package.

2303.4.1.3 Truss placement diagram. The truss manufacturer shall provide a truss placement diagram that identifies the proposed location for each individually designated truss and references the corresponding truss design drawing. The truss placement diagram shall be provided as part of the truss submittal package, and with the shipment of trusses delivered to the job site. Trussplacement diagrams shall not be required to bear the seal or signature of the truss designer.Exception: When the truss placement diagram is prepared under the direct supervision of a registered design professional, it is required to be signed and sealed.

2303.4.1.4 Truss submittal package. The truss submittal package shall consist of each individual truss design drawing, the truss placement diagram for the project, the truss member permanent bracing specification and, as applicable, the cover sheet/truss index sheet.

Fastening Schedule - added actual nail sizes to standard naming convention.Minor revisions to Protection against decay & termites. Primarily editiorial.Allows use of AF&PA SDPWS for lateral design.Design of Wood Diaphragms. Significant revisions to section. Review details if needed.Allowable Stress Design. Minor revisions. Review details if needed.LRFD. Significant revisions. Review details if needed.Conventional Light-Frame Construction.Revised language regarding design of portions exceeding limitations. (see also 2308.4)

Design of Elements (see also 2308.1 above)

2303.4.1.5 Truss member permanent bracing. Where permanent bracing of truss members is required on the truss design drawings, it shall be accomplished by one of the following methods:1. The trusses shall be designed so that the buckling of any individual truss member can be resisted internally by the structure (e.g. buckling member T-bracing, L-bracing, etc.) of the individual truss. The truss individual member buckling reinforcement shall be installed as shown on the truss design drawing or on supplemental truss member buckling reinforcement diagrams provided by the truss designer.2. Permanent bracing shall be installed using standard industry bracing details that conform with generally accepted engineering practice. Individual truss member continuous lateral bracing location(s) shall be shown on the truss design drawing.

2303.4.1.6 Anchorage. All transfer of loads and anchorage of each truss to the supporting structure is the responsibility of the registered design professional.

2303.4.1.7 Alterations to trusses. Truss members and components shall not be cut, notched, drilled, spliced or otherwise altered in any way without written concurrence and approval of a registered design professional.Alterations resulting in the addition of loads to any member (e.g., HVAC equipment, water heater) shall not bepermitted without verification that the truss is capable of supporting such additional loading.

2303.4.2 Metal-plate-connected trusses. In addition to Sections 2303.4.1 through 2303.4.1.7, the design, manufacture and quality assurance of metal-plate-connected wood trusses shall be in accordance with TPI 1. Manufactured trusses shall comply with Section 1704.6 as applicable.

2308.1.1 Portions exceeding limitations of conventional construction. When portions of a building of otherwise conventional construction exceed the limits of Section 2308.2, these portions and the supporting load path shall be designed in accordance with accepted engineering practice and the provisions of this code. For the purposes of this section, the term “portions” shall mean parts of buildings containing volume and area such as a room or a series of rooms.

Bearing wall floor-to-floor heights shall not exceed a stud height of 10 feet (3048 mm) plus a height of floor framing not to exceed 16 inches (406 mm).

Loads as determined in Chapter 16 shall not exceed the following:3.1. Average dead loads shall not exceed 15 psf (718 N/m2) for combined roof and ceiling, exterior walls, floors and partitions.Exceptions:1. Subject to the limitations of Sections 2308.11.2 and 2308.12.2, stone or masonry veneer up to the lesser of 5 inches (127 mm) thick or 50 psf (2395 N/m2) and installed in accordance with Chapter 14 is permitted to a height of 30 feet (9144 mm) above a noncombustible foundation, with an additional 8 feet (2438 mm) permitted for gable ends.2. Concrete or masonry fireplaces, heaters and chimneys shall be permitted in accordance with the provisions of this code.

Added section regarding Alternate bracing wall panel adjacent to a window or door opening. Review for details.

Seismic - A number of additions/deletions. Review for details.Seismic - A number of additions/deletions. Review for details.

2308.4 Design of elements. Combining of engineered elements or systems and conventionally specified elements or systems is permitted subject to the following limits: 2308.4.1 Elements exceeding limitations of conventional construction. When a building of otherwise conventional construction contains structural elements exceeding the limits of Section 2308.2, these elements and the supporting load path shall be designed in accordance with accepted engineering practice and the provisions of this code. 2308.4.2 Structural elements or systems not described herein. When a building of otherwise conventional construction contains structural elements or systems not described in Section 2308, these elements or systems shall be designed in accordance with accepted engineering practice and the provisions of this code. The extent of such design need only demonstrate compliance of the nonconventional elements with other applicable provisions of this code and shall be compatible with the performance of the conventionally framed system.

2308.9.3 Bracing. Braced wall lines shall consist of braced wall panels that meet the requirements for location, type and amount of bracing as shown in Figure 2308.9.3, specified in Table 2308.9.3(1) and are in line or offset from each other by not more than 4 feet (1219 mm). Bracedwall panels shall start not more than 121/2-feet (3810 mm) from each end of a braced wall line. Braced wall panels shall be clearly indicated on the plans. Construction of braced wall panels shall be by one of the following methods:

Uplift Connections. Values did not change. Revised reference to source & added table of adjustment factors for height & exposure.

IBC-03

1611.2 Ponding instability. Ponding refers to the retention of water due solely to the deflection of relatively flat roofs. Roofs with a slope less than one-fourth unit vertical in 12 units horizontal (2-percent slope) shall be investigated by structural analysis to ensure that they possess adequate stiffness to preclude progressive deflection (i.e., instability) as rain falls on them or meltwater is created from snow on them. The larger of snow load or rain load shall be used in this analysis. The primary drainage system within an area subjected to ponding shall be considered to be blocked in this analysis

Note: revisions to truss section are both an expansion on and a consolidation of two sections in the IBC 2003 (2303.4 & 2308.10.7). Red Text indicates areas of change.

2308.10.7 Wood trusses.2308.10.7.1 Design. Wood trusses shall be designed in accordance with the requirements of Chapter 23 and accepted engineering practice. embers are permitted to be joined by nails, glue, bolts, timber connectors, metalconnector plates or other approved framing devices.

2303.4.1 Truss design drawings. Truss construction documents shall be prepared by a registered design professional and shall be provided to the building official and approved prior to installation. These construction documents shall include, at a minimum, the information specified below. Truss shop drawings shall be provided with the shipment of trusses delivered to the job site.

1. Slope or depth, span and spacing;2. Location of joints;3. Required bearing widths;4. Design loads as applicable;5. Top chord live load (including snow loads);6. Top chord dead load;7. Bottom chord live load;8. Bottom chord dead load;9. Concentrated loads and their points of application;10. Controlling wind and earthquake loads;11. Adjustments to lumber and metal connector plate design value for conditions of use;12. Each reaction force and direction;13. Metal connector plate type, size, thickness or gage, and the dimensioned location of each metal connector plate except where symmetrically located relative to the joint interface;14. Lumber size, species and grade for each member;15. Connection requirements for:15.1. Truss to truss girder;15.2. Truss ply to ply; and15.3. Field species;16. Calculated deflection ratio or maximum deflection for live and total load;17. Maximum axial compression forces in the truss members to design the size, connections and anchorage of the permanent continuous lateral bracing. Forces shall be shown on the truss construction documents or on supplemental documents; and 18. Required permanent truss member bracing location.

(added from IRC-2003)

2308.10.7.2 Bracing. The bracing of wood trusses shall comply with their appropriate engineered design.

2308.10.7.3 Alterations to trusses. Truss members and components shall not be cut, notched, drilled, spliced or otherwise altered in any way without written concurrence and approval of a registered design professional. Alterations resulting in the addition of loads to any member (e.g., HVAC equipment, water heater) shall not be permitted without verification that the truss is capable of supporting such additional loading.

2303.4 Trusses. Metal-plate-connected wood trusses shall be manufactured as required by TPI 1. Each manufacturer of trusses using metal plate connectors shall retain an approved agency to make unscheduled inspections of truss manufacturing and delivery operations. The inspection shall cover all phases of truss operations, including lumber storage, handling, cutting fixtures, presses or rollers, manufacturing, bundling and banding.

3. Loads as determined in Chapter 16 shall not exceed the following:3.1. Average dead loads shall not exceed 15 psf (718 N/m2) for roofs and exterior walls, floors and partitions.

2308.4 Design of portions. Where a building of otherwise conventionalconstruction contains nonconventional structural elements,those elements shall be designed to resist the forcesspecified in Chapter 16. The extent of such design need onlydemonstrate compliance of nonconventional elements withother applicable provisions of this code, and shall be compatiblewith the performance of the conventional framed system.

8 feet

11. Adjustments to lumber and metal connector plate design value for conditions of use;

13. Metal connector plate type, size, thickness or gage, and the dimensioned location of each metal connector plate except where symmetrically located relative to the joint interface;

to design the size, connections and anchorage of the permanent continuous lateral bracing. Forces shall be shown on the truss

The following comparison is focused on loading issues as they might relate to structural building components (SBC). IRC changes in both printed and pdf versions are marked for change or deletion.Significant changes are indicated by red text.

IRC Section Comments

Part 1 - Administration Minor modifications, mostly related to flood requirements.

Part 2 - Definitions Minor modifications.

Part 3 - Building Planning & Const. Significant changes throughout all chapters. - see details.

Chapter 3 - Building Planning Significant revisions to basic design requirements

Chapter 4 - Foundations Significant revisions to basic design requirements

Chapter 5 - Floors Revised Header table R502.5(1) to include up to 70 psf ground snow.

Chapter 6 - Walls

Chapter 7 - Wall Coverings Added horiz. gypsum board diaphragm & waterproof backing to R702.3

Chapter 8 - Roof/Ceiling Const. Added applicability limits for snow design to 0.7pg. Chapter 9 - Roof Assemblies Significant changes to roof coverings and fasteners, including consideration of hail concerns.

Chapter 10 - Chimneys Sigificant changes to masonry heaters and fireplaces.

Part 4 - Energy Conservation Not reviewed

Part 5 - Mechanical Not reviewed

Part 6 - Fuel Gas Not reviewed

Part 7 - Plumbing Not reviewed

Part 8 - Electrical Not reviewed

Part 9 - Referenced Standards Changes not marked. Review with care for specific applications.

Chapter 43 AF&PA NDS-05, APA E30-03, ASCE 7-05, NFPA 13-02,

Revised Fastener Table R602.3(1) to include actual nail sizes & alternate attachments. Significant braced wall line revisions

The following comparison is focused on loading issues as they might relate to structural building components (SBC). IRC changes in both printed and pdf versions are marked for change or deletion.

Comments

Minor modifications, mostly related to flood requirements.

Minor modifications.

Significant changes throughout all chapters. - see details.

Significant revisions to basic design requirements

Significant revisions to basic design requirements

Revised Header table R502.5(1) to include up to 70 psf ground snow.

Added horiz. gypsum board diaphragm & waterproof backing to R702.3 Added applicability limits for snow design to 0.7pg.

Significant changes to roof coverings and fasteners, including consideration of hail concerns.

Sigificant changes to masonry heaters and fireplaces.

Not reviewed

Not reviewed

Not reviewed

Not reviewed

Not reviewed

Changes not marked. Review with care for specific applications.

AF&PA NDS-05, APA E30-03, ASCE 7-05, NFPA 13-02,

Revised Fastener Table R602.3(1) to include actual nail sizes & alternate attachments. Significant braced wall line

Impact

nonenonesee details for each chapter

see details

IRC Details

SectionCHAPTER 3R301.1

R301.2.1.1

Table R301.2(1)R301.2.1.2

R301.2.2

R301.2.2.2.1

R301.2.2.2.2

R301.2.2.3 & 4

Table R301.5

R305.1

R308.1R308.1

R309

R310 & R311R312 & R313R314R317

R320R323

CHAPTER 4

CHAPTER 5R502.1.6

Table R502.5(1)

R502.11

Table R203.2.1(1)

R505

CHAPTER 6R602.1.3

Table R602.3(1)

Tabler R602.3(2)

R602.10Table R602.10.1

R602.10.6

R602.6.1(mainly reorg)

R602.10.11

R603R606R611R613

CHAPTER 7

703

Table R703.4

R703.7R703.8

CHAPTER 8R802.1.5

R802.10

R804R806.3

CHAPTER 9


IRC-06

Climatic & Geographic - revised for flood, hail, & termite issues.

Weights of materials for seismic evaluation (only changed portions shown)

Revisions related to seismice categories C & D. Review if applicable.

Minimum Uniformly Distributed Live Loads (footnotes revised per WTCA submitted change)

R301.1 Application. Buildings and structures, and all parts thereof, shall be constructed to safely support all loads, including dead loads, live loads, roof loads, flood loads, snow loads, wind loads and seismic loads as prescribed by this code. The construction of buildings and structures in accordance with the provisions of this code shall result in a system that provides a complete load path that meets all requirements for the transfer of all loads from their point of origin through the load-resisting elements to the foundation. Buildings and structures constructed as prescribed by this code are deemed to comply with the requirements of this section.

R301.2.1.1 Design criteria. Construction in regions where the basic wind speeds from Figure R301.2(4) equal or exceed 100 miles per hour (45 m/s) in hurricane-prone regions, or 110 miles per hour (49m/s) elsewhere, shall be designed in accordance with one of the following:

R301.2.1.2 Protection of openings. Windows in buildings located in windborne debris regions shall have glazed openings protected from windborne debris. Glazed opening protection for windborne debris shall meet the requirements of the Large Missile Test of an approved impact resisting standard orASTME 1996 and ASTM E 1886 referenced therein.

Seismic Provisions in general reflect D0 in addition to D1 & D2.

R301.2.2.2.1 Weights of materials. Average dead loads shall not exceed 15 pounds per square foot (720 Pa) for the combined roof and ceiling assemblies (on a horizontal projection) or 10 pounds per square foot (480 Pa) for floor assemblies, except as further limited by Section R301.2.2. Dead loads for walls above grade shall not exceed:

Exceptions:1. Roof and ceiling dead loads not exceeding 25 pounds per square foot (1190 Pa) shall be permitted provided the wall bracing amounts in Chapter 6 are increased in accordance with Table R301.2.2.2.1.2. Light-frame walls with stone or masonry veneer shall be permitted in accordance with the provisions of Sections R702.1 and R703.3. Fireplaces and chimneys shall be permitted in accordance with Chapter 10.

R301.2.2.2.2 Irregular buildings. Prescriptive construction as regulated by this code shall not be used for irregular structures located in Seismic Design Categories C, D0, D1 and D2. Irregular portions of structures shall be designed in accordance with accepted engineering practice to the extent the irregular features affect the performance of the remaining structural system. When the forces associated with the irregularity are resisted by a structural system designed in accordance with accepted engineering practice, design of the remainder of the building shall be permitted using the provisions of this code. A building or portion of a building shall be considered to be irregular when one or more of the following conditions occur:

Note: IBC indludes an additional requirement for a minimum 10 psf DL for attics with limited storage.

Location on Lot

b. Attics without storage are those where the maximum clear height between joist and rafter is less than 42 inches, or where there are not two or more adjacent trusses with the same web configuration capable of containing a rectangle 42 inches high by 2 feet wide, or greater, located within the plane of the truss. For attics without storage, this live load need not be assumed to act concurrently with any other live load requirements.

g. For attics with limited storage and constructed with trusses, this live load need be applied only to those portions of the bottom chord where there are two or more adjacent trusses with the same web configuration capable of containing a rectangle 42 inches high or greater by 2 feet wide or greater, located within the plane of the truss. The rectangle shall fit between the top of the bottom chord and the bottom of any other truss member, provided that each of the following criteria is met:1. The attic area is accessible by a pull-down stairway or framed opening in accordance with Section R807.1; and2. The truss has a bottom chord pitch less than 2:12.h. Attic spaces served by a fixed stair shall be designed to support the minimum live load specified for sleeping rooms.

R302.1 Exterior walls. Construction, projections, openings and penetrations of exterior walls of dwellings and accessory buildings shall comply with Table R302.1. These provisions shall not apply to walls, projections, openings or penetrations in walls that are perpendicular to the line used to determine the fire separation distance. Projections beyond the exterior wall shall not extend more than 12 inches (305 mm) into the areas where openings are prohibited.Exceptions:1. Detached tool sheds and storage sheds, playhouses and similar structures exempted from permits are not required to provide wall protection based on location on the lot. Projections beyond the exterior wall shall not extend over the lot line.2. Detached garages accessory to a dwelling located within 2 feet (610 mm) of a lot line are permitted to have roof eave projections not exceeding 4 inches (102 mm).3. Foundation vents installed in compliance with this code are permitted.

Minimum Ceiling Heights

Glazing

Garages & Carports (added)

Changes to emergency escape and egress requirements. Review if applicable.Changes to guards & smoke alarms. Review if applicable.Significant changes to Foam Plastics. Review if applicable.Dwelling Unit Separation

3. For rooms with sloped ceilings, at least 50 percent of the required floor area of the room must have a ceiling height of at least 7 feet (2134 mm) and no portion of the required floor area may have a ceiling height of less than 5 feet (1524 mm).

R308.1 Identification. Except as indicated in Section R308.1.1 each pane of glazing installed in hazardous locations as defined in Section R308.4 shall be provided with a manufacturer’s designation specifying who applied the designation, designating the type of glass and the safety glazing standard with which it complies, which is visible in the final installation. The designation shall be acid etched, sandblasted, ceramic-fired, laser etched, embossed, or be of a type which once applied cannot be removed without being destroyed. A label shall be permitted in lieu of the manufacturer’s designation.Exceptions:1. For other than tempered glass, manufacturer’s designations are not required provided the building official approves the use of a certificate, affidavit or other evidence confirming compliance with this code.2. Tempered spandrel glass is permitted to be identified by the manufacturer with a removable paper designation.

R309.1.2 Other penetrations. Penetrations through the separation required in Section R309.2 shall be protected by filling the opening around the penetrating item with approved material to resist the free passage of flame and products of combustion.

R309.2 Separation required. The garage shall be separated from the residence and its attic area by not less than 1/2-inch (12.7 mm) gypsum board applied to the garage side. Garages beneathhabitable rooms shall be separated from all habitable rooms above by not less than 5/8-inch (15.9 mm) Type X gypsum board or equivalent. Where the separation is a floor-ceiling assembly,the structure supporting the separation shall also be protected by not less than 1/2-inch (12.7 mm) gypsum board or equivalent. Garages located less than 3 feet (914 mm) from a dwelling unit on the same lot shall be protected with not less than 1/2-inch (12.7 mm) gypsum board applied to the interior side of exterior walls that are within this area. Openings in these walls shall be regulated by SectionR309.1. This provision does not apply to garage walls that are perpendicular to the adjacent dwelling unit wall.

Protection against decay

R317.1 Two-family dwellings. Dwelling units in two-family dwellings shall be separated from each other by wall and/or floor assemblies having not less than a 1-hour fire-resistance rating when tested in accordance withASTME 119. Fire-resistance-rated floor-ceiling and wall assemblies shall extend to and be tight against the exterior wall, and wall assemblies shall extend to the underside of the roof sheathing.Exceptions:1. A fire-resistance rating of 1/2 hour shall be permitted in buildings equipped throughout with an automatic sprinkler system installed in accordance with NFPA 13.2. Wall assemblies need not extend through attic spaces when the ceiling is protected by not less than 5/8-inch (15.9 mm) Type X gypsum board and an attic draft stop constructed as specified in Section R502.12.1 is provided above and along the wall assembly separating the dwellings. The structural framing supporting the ceiling shall also be protected by not less than 1/2 -inch (12.7 mm) gypsum board or equivalent.

R317.2.1 Continuity. The fire-resistance-rated wall or assembly separating townhouses shall be continuous from the foundation to the underside of the roof sheathing, deck or slab. The fire-resistance rating shall extend the full length of the wall or assembly, including wall extensions through and separating attached enclosed accessory structures.

R319.1 Location required. Protection from decay shall be provided in the following locations by the use of naturally durable wood or wood that is preservative treated in accordance with AWPA U1 for the species, product, preservative and end use. Preservatives shall be listed in Section 4 of AWPA U1.

R319.1.1 Field treatment. Field-cut ends, notches and drilled holes of preservative-treatedwood shall be treated in the field in accordance with AWPA M4.

R319.1.2 Ground contact. All wood in contact with the ground, embedded in concrete in direct contact with the ground or embedded in concrete exposed to the weather that supports permanent structures intended for human occupancy shall be approved pressure-preservative-treated wood suitable for ground contact use, except untreated wood may be used where entirely below groundwater level or continuously submerged in fresh water.

R319.1.4 Wood columns. Wood columns shall be approved wood of natural decay resistance or approved pressure-preservative-treated wood.Exceptions:1. Columns exposed to the weather or in basements when supported by concrete piers or metal pedestals projecting 1 inch (25.4 mm) above a concrete floor or 6 inches (152 mm) above exposed earth and the earth is covered by an approved impervious moisture barrier.2. Columns in enclosed crawl spaces or unexcavated areas located within the periphery of the building when supported by a concrete pier or metal pedestal at a height more than 8 inches (203mm) from exposed earth and the earth is covered by an impervious moisture barrier.

R319.1.5 Exposed glued-laminated timbers. The portions of glued-laminated timbers that form the structural supports of a building or other structure and are exposed to weather and not properly protected by a roof, eave or similar covering shall be pressure treated with preservative, or be manufactured from naturally durable or preservative-treated wood.

R319.3 Fasteners. Fasteners for pressure-preservative and fire-retardant-treated wood shall be of hot-dipped zinc-coated galvanized steel, stainless steel, silicon bronze or copper. The coating weights for zinc-coated fasteners shall be in accordance with ASTM A 153.Exceptions:1. One-half-inch (12.7 mm) diameter or larger steel bolts.2. Fasteners other than nails and timber rivets shall be permitted to be of mechanically deposited zinc coated steel with coating weights in accordance with ASTM B 695, Class 55, minimum.

Protection against termites. Review if applicableFlood Resistant Construction. Review if applicable.

Foundations.Significant changes. Review if applicable.FloorsAdded provisions for log structures. Review of applicable

Girder/Header spans. Revised to include columns for 70 psf ground snow load.

R502.11 Wood trusses.

WallsAdded provisions for log structures. Review of applicable

Fastener Schedule. Revised to include actual nail sizes & footnote i

Alternate Attachments. Revised thickness categories & spacing requirements. Review if applicable.

R502.2.1 Framing at braced wall lines. A load path for lateral forces shall be provided between floor framing and braced wall panels located above or below a floor, as specified in Section R602.10.8.

R502.7 Lateral restraint at supports. Joists shall be supported laterally at the ends by full-depth solid blocking not less than 2 inches (51 mm) nominal in thickness; or by attachment to a full-depth header, band or rim joist, or to an adjoining stud or shall be otherwise provided with lateral support to prevent rotation.Exception: In Seismic Design Categories D0, D1 and D2, lateral restraint shall also be provided at each intermediate support.

R502.11.2 Bracing. Trusses shall be braced to prevent rotation and provide lateral stability in accordance with the requirements specified in the construction documents for the building and on the individual truss design drawings. In the absence of specific bracing requirements, trusses shall be braced in accordance with the Building Component Safety Information (BCSI 1-03) Guide to Good Practice for Handling, Installing & Bracing of Metal Plate Connected Wood Trusses.

Allowable Spans and load for WSP. Added columns for allowable live loads, otherwise table did not change.

Steel Floor Framing. Applicability limit revised from 36 foot to 40 foot width. See other changes if applicable.

R602.3.2 Top plate.Wood studwalls shall be capped with a double top plate installed to provide overlapping at corners and intersections with bearing partitions. End joints in top plates shall be offset at least 24 inches (610 mm). Joints in plates need not occur over studs. Plates shall be not less than 2-inches (51 mm) nominal thickness and have a width at least equal to the width of the studs.

Spacing of fasteners on floor sheathing panel edges applies to panel edges supported by framing members and required blocking and at all floor perimeters only. Spacing of fasteners on roof sheathing panel edges applies to panel edges supported by framing members and required blocking. Blocking of roof or floor sheathing panel edges perpendicular to the framing members need not be provided except as required by other provisions of this code. Floor perimeter shall be supported by framing members or solid blocking.

Wall Bracing. Review for applicablity for local requirements.

Alternate Braced Wall Panels. (significant revisions)

R602.6 Drilling and notching–studs. Drilling and notching of studs shall be in accordance with the following:1. Notching. Any stud in an exterior wall or bearing partition may be cut or notched to a depth not exceeding 25 percent of its width. Studs in nonbearing partitions may be notched to a depth not to exceed 40 percent of a single stud width.2. Drilling. Any stud may be bored or drilled, provided that the diameter of the resulting hole is no more than 60 percent of the stud width, the edge of the hole is no more than 5/8 inch (16 mm) to the edge of the stud, and the hole is not located in the same section as a cut or notch. Studs located in exterior walls or bearing partitions drilled over 40 percent and up to 60 percent shall also be doubled with no more than two successive doubled studs bored. See Figures R602.6(1) and R602.6(2).Exception: Use of approved stud shoes is permitted when they are installed in accordance with the manufacturer’s recommendations.

R602.6.1 Drilling and notching of top plate. When piping or ductwork is placed in or partly in an exterior wall or interior load-bearing wall, necessitating cutting, drilling or notching of the top plate by more than 50 percent of its width, a galvanized metal tie of not less than 0.054 inch thick (1.37 mm) (16 ga) and 1 1/2 inches (38 mm) wide shall be fastened across and to the plate at each side of the opening with not less than eight 16d nails at each side or equivalent. See Figure R602.6.1.

Revised Wall Bracing Table - didn't actually change much. Added phrase 'in accordance with Section R602.10' to each description of amount of bracing. Revised footnote c to indicate two types of alternate braced wall panel methods.

R602.10.6 Alternate braced wall panel construction methods. Alternate braced wall panels shall be constructed in accordance with Sections R602.10.6.1 and R602.10.6.2. R602.10.6.1 Alternate braced wall panels. Alternate braced wall lines constructed in accordance with one of the following provisions shall be permitted to replace each 4 feet (1219 mm) of bracedwall panel as required by SectionR602.10.4. The maximum height and minimum width of each panel shall be in accordance with Table R602.10.6:

1. In one-story buildings, each panel shall be sheathed on one face with 3/8-inch-minimum-thickness (10 mm) wood structural panel sheathing nailed with 8d common or galvanized box nails in accordance with Table R602.3(1) and blocked at all wood structural panel sheathing edges. Two anchor bolts installed in accordance with Figure R403.1(1) shall be provided in each panel. Anchor bolts shall be placed at panel quarter points. Each panel end stud shall have a tie-down device fastened to the foundation, capable of providing an uplift capacity in accordance with Table R602.10.6. The tie down device shall be installed in accordance with the manufacturer’s recommendations. The panels shall be supported directly on a foundation or on floor framing supported directly on a foundation which is continuous across the entire length of the braced wall line. This foundation shall be reinforced with not less than one No. 4 bar top and bottom. When the continuous foundation is required to have a depth greater than 12 inches (305 mm), a minimum 12-inch-by-12-inch (305mmby 305 mm) continuous footing or turned down slab edge is permitted at door openings in the braced wall line. This continuous footing or turned down slab edge shall be reinforced with not less than one No. 4 bar top and bottom. This reinforcement shall be lapped 15 inches (381 mm) with the reinforcement required in the continuous foundation located directly under the braced wall line.

2. In the first story of two-story buildings, each braced wall panel shall be in accordance with Item 1 above, except that the wood structural panel sheathing shall be installed on both faces, sheathingedge nailing spacing shall not exceed 4 inches (102 mm) on center, at least three anchor bolts shall be placed at one-fifth points.

R602.10.6.2 Alternate braced wall panel adjacent to a door or window opening. Alternate braced wall panels constructed in accordance with one of the following provisions are also permitted to replace each 4 feet (1219 mm) of braced wall panel as required by Section R602.10.4 for use adjacent to a window or door opening with a full-length header:

1. In one-story buildings, each panel shall have a length of not less than 16 inches (406 mm) and a height of not more than 10 feet (3048 mm). Each panel shall be sheathed on one face with a singlelayer of 3/8-inch-minimum-thickness (10 mm) wood structural panel sheathing nailed with 8d common or galvanized box nails in accordance with Figure R602.10.6.2. The wood structural panel sheathing shall extend up over the solid sawn or glued-laminated header and shall be nailed in accordance with Figure R602.10.6.2. Use of a built-up header consisting of at least two 2 x 12sand fastened in accordance with Table R602.3(1) shall be permitted. A spacer, if used, shall be placed on the side of the built-up beam opposite the wood structural panel sheathing. The headershall extend between the inside faces of the first full-length outer studs of each panel. The clear span of the header between the inner studs of each panel shall be not less than 6 feet (1829 mm) andnot more than 18 feet (5486 mm) in length. A strap with an uplift capacity of not less than 1000 pounds (4448 N) shall fasten the header to the side of the inner studs opposite the sheathing. Oneanchor bolt not less than 5/8-inch-diameter (16 mm) and installed in accordance with Section R403.1.6 shall be installed in the center of each sill plate. The studs at each end of the panel shall havea tie-down device fastened to the foundation with an uplift capacity of not less than 4,200 pounds (18 683 N).Where a panel is located on one side of the opening, the header shall extend between the inside face of the first full-length stud of the panel and the bearing studs at the other end of the opening. A strapwith an uplift capacity of not less than 1000 pounds (4448 N) shall fasten the header to the bearing studs. The bearing studs shall also have a tie-down device fastened to the foundation with an upliftcapacity of not less than 1000 pounds (4448 N). The tie-down devices shall be an embeddedstrap type, installed in accordance with the manufacturer’s recommendations. The panels shall besupported directly on a foundation which is continuous across the entire length of the braced wall line. The foundation shall be reinforced with not less than one No. 4 bar top and bottom.Where the continuous foundation is required to have a depth greater than 12 inches (305 mm), a minimum 12-inch-by-12-inch (305 mm by 305 mm) continuous footing or turned down slab edgeis permitted at door openings in the braced wall line. This continuous footing or turned down slab edge shall be reinforced with not less than one No. 4 bar top and bottom. This reinforcement shall be2. In the first story of two-story buildings, each wall panel shall be braced in accordance with Item 1 above, except that each panel shall have a length of not less than 24 inches (610 mm).

R602.10.8 Connections. Braced wall line sole plates shall be fastened to the floor framing and top plates shall be connected to the framing above in accordance with Table R602.3(1). Sills shall be fastened to the foundation or slab in accordance with Sections R403.1.6 and R602.11. Where joists are perpendicular to the braced wall lines above, blocking shall be provided under and in line with the braced wall panels. Where joists are perpendicular to braced wall lines below, blocking shall be provided over and in line with the braced wall panels. Where joists are parallel to braced wall lines above or below, a rim joist or other parallel framing member shall be provided at thewall to permit fastening per Table R602.3(1).

Steel Wall Framing. Review changes if applicable.General Masonry Masonry Construction. Review changes if applicable.ICF. Review changes if applicableExterior Windows and Glass Doors. Review changes if applicable.

Wall Coverings. (see new sections)

Exterior Covering

R602.10.11 Bracing in Seismic Design Categories D0, D1 and D2. Structures located in Seismic Design Categories D0, D1 and D2 shall have exterior and interior braced wall lines.R602.10.11.1 Braced wall line spacing. Spacing between braced wall lines in each story shall not exceed 25 feet (7620 mm) on center in both the longitudinal and transverse directions.Exception: In one- and two-story buildings, spacing between two adjacent braced wall lines shall not exceed 35 feet (10 363 mm) on center in order to accommodate one single room not exceeding 900 square feet (84 m2) in each dwelling unit. Spacing between all other braced wall lines shall not exceed 25 feet (7620 mm).R602.10.11.2 Braced wall panel location. Exterior braced wall lines shall have a braced wall panel at each end of the braced wall line.

R602.10.11.3 Collectors. A designed collector shall be provided if a braced wall panel is not located at each end of a braced wall line as indicated in Section R602.10.11.2, or, when using the Section R602.10.11.2 exception, if a braced wall panel is more than 8 feet (2438 mm) from each end of a braced wall line.

R702.3.7 Horizontal gypsum board diaphragm ceilings. Use of gypsum board shall be permitted on wood joists to create a horizontal diaphragm in accordance with Table R702.3.7. Gypsum board shall be installed perpendicular to ceiling framing members. End joints of adjacent courses of board shall not occur on the same joist. The maximum allowable diaphragm proportions shall be 11/2:1 between shear resisting elements. Rotation or cantilever conditions shall not be permitted. Gypsum board shall not be used in diaphragm ceilings to resist lateral forces imposed by masonry or concrete construction. All perimeter edges shall be blocked using wood members not less than 2-inch (51 mm) by 6-inch (152 mm) nominal dimension. Blocking material shall be installed flat over the top plate of the wall to provide a nailing surface not less than 2 inches (51 mm) in width for the attachment of the gypsum board.

R702.3.8 Water-resistant gypsum backing board. Gypsum board used as the base or backer for adhesive application of ceramic tile or other required nonabsorbent finish material shall conform to ASTM C 630 or C 1178. Use of water-resistant gypsum backing board shall be permitted on ceilings where framing spacing does not exceed 12 inches (305 mm) on center for 1/2-inch-thick (13 mm) or 16 inches (406 mm) for 5/8-inch-thick (16 mm) gypsum board. Water-resistant gypsum board shall not be installed over a vapor retarder in a shower or tub compartment. Cut or exposed edges, including those at wall intersections, shall be sealed as recommended by the manufacturer. R702.3.8.1 Limitations. Water resistant gypsum backing board shall not be used where there will be direct exposure to water, or in areas subject to continuous high humidity.

R703.1 General. Exterior walls shall provide the building with a weather-resistant exterior wall envelope. The exterior wall envelope shall include flashing as described in Section R703.8. The exterior wall envelope shall be designed and constructed in a manner that prevents the accumulation of water within the wall assembly by providing a water-resistant barrier behind the exterior veneer as required by Section R703.2. and a means of draining water that enters the assembly to the exterior. Protection against condensation in the exterior wall assembly shall be provided in accordance with Chapter 11 of this code.

Siding Attachment & Minimum Thickness changes. Review as applicable. Primarily related to footnotes.

Stone & Masonry Veneer. Review changes if applicable.Flashing

Exceptions:1. A weather-resistant exterior wall envelope shall not be required over concrete or masonry walls designed in accordance with Chapter 6 and flashed according to Section R703.7 or R703.8.2. Compliance with the requirements for a means of drainage, and the requirements of Section R703.2 and Section R703.8, shall not be required for an exterior wall envelope that has been demonstrated to resist wind-driven rain through testing of the exterior wall envelope, including joints, penetrations and intersections with dissimilar materials, in accordance with ASTM E 331 under the following conditions:2.1. Exterior wall envelope test assemblies shall include at least one opening, one control joint, one wall/eave interface and one wall sill. All tested openings and penetrations shall be representativeof the intended end-use configuration. 2.2. Exterior wall envelope test assemblies shall be at least 4 feet (1219 mm) by 8 feet (2438 mm) in size.2.3. Exterior wall assemblies shall be tested at a minimum differential pressure of 6.24 pounds per square foot (299 Pa).2.4. Exterior wall envelope assemblies shall be subjected to a minimum test exposure duration of 2 hours. The exterior wall envelope design shall be considered to resist wind-driven rain where the results of testing indicate that water did not penetrate: control joints in the exterior wall envelope; joints at the perimeter of openings penetration; or intersections of terminations with dissimilar materials.

R703.2 Water-resistive barrier. One layer of No. 15 asphalt felt, free from holes and breaks, complying with ASTM D 226 for Type 1 felt or other approved water-resistive barrier shall be applied over studs or sheathing of all exterior walls. Such felt or material shall be applied horizontally, with the upper layer lapped over the lower layer not less than 2 inches (51 mm). Where joints occur, felt shall be lapped not less than 6 inches (152 mm). The felt or other approved material shall be continuous to the top ofwalls and terminated at penetrations and building appendages in a manner to meet the requirements of the exterior wall envelope as described in Section R703.1.Exception: Omission of the water-resistive barrier is permitted in the following situations:1. In detached accessory buildings.2. Under exterior wall finish materials as permitted in Table R703.4.3. Under paperbacked stucco lath when the paper backing is an approved weather-resistive sheathing paper.

R703.4 Attachments. Unless specified otherwise, all wall coverings shall be securely fastened in accordance with Table R703.4 or with other approved aluminum, stainless steel, zinc-coated or other approved corrosion-resistive fasteners. Where the basic wind speed per Figure R301.2(4) is 110 miles per hour (49 m/s) or higher, the attachment of wall coverings shall be designed to resist the component and cladding loads specified in Table R301.2(2), adjusted for height and exposure in accordance with Table R301.2(3).

R703.6.3 Water-resistive barriers. Water-resistive barriers shall be installed as required in Section R703.2 and, where applied over wood-based sheathing, shall include a water-resistive vapor-permeable barrier with a performance at least equivalent to two layers of Grade D paper. Exception: Where the water-resistive barrier that is applied over wood-based sheathing has a water resistance equal to or greater than that of 60 minute Grade D paper and is separated from the stucco by an intervening, substantially nonwater-absorbing layer or designed drainage space.

Roof-Ceiling ConstructionAdded Structural Log requirements. Review if applicable.

Note: see added note on rafter span tables.Wood Trusses (editorial, either snow or roof live load will control)R802.10.1 Truss design drawings.

R703.8 Flashing. Approved corrosion-resistant flashing shall be applied shingle-fashion in such a manner to prevent entry of water into the wall cavity or penetration of water to the building structural framing components. The flashing shall extend to the surface of the exterior wall finish. Approved corrosion-resistant flashings shall be installed at all of the following locations:1. Exterior window and door openings. Flashing at exterior window and door openings shall extend to the surface of the exterior wall finish or to the water-resistive barrier for subsequent drainage.

R703.11 Vinyl siding. Vinyl siding shall be certified and labeled as conforming to the requirements of ASTM D 3679 by an approved quality control agency.R703.11.1 Installation. Vinyl siding, soffit and accessories shall be installed in accordance with the manufacturer’s installation instructions.

R802.2 Design and construction. The framing details required in Section R802 apply to roofs having a minimum slope of three units vertical in 12 units horizontal (25-percent slope) or greater. Roof-ceilings shall be designed and constructed in accordance with the provisions of this chapter and Figures R606.11(1), R606.11(2) and R606.11(3) or in accordance with AFPA/NDS. Components of roof-ceilings shall be fastened in accordance with Table R602.3(1).

R802.3.1 Ceiling joist and rafter connections. Ceiling joists and rafters shall be nailed to each other in accordance with Table R802.5.1(9), and the rafter shall be nailed to the top wall plate in accordance with Table R602.3(1). Ceiling joists shall be continuous or securely joined in accordance with Table R802.5.1(9) where they meet over interior partitions and are nailed to adjacent rafters to provide a continuous tie across the building when such joists are parallel to the rafters. Where ceiling joists are not connected to the rafters at the top wall plate, joists connected higher in the attic shall be installed as rafter ties, or rafter ties shall be installed to provide a continuous tie. Where ceiling joists are not parallel to rafters, rafter ties shall be installed. Rafter ties shall be a minimum of 2-inch by 4-inch (51 mm by 102 mm) (nominal), installed in accordance with the connection requirements in Table R802.5.1(9), or connections of equivalent capacities shall be provided. Where ceiling joists or rafter ties are not provided, the ridge formed by these rafters shall be supported by a wall or girder designed in accordance with accepted engineering practice. Collar ties or ridge straps to resist wind uplift shall be connected in the upper third of the attic spacein accordance with Table R602.3(1).Collar ties shall be a minimum of 1-inch by 4-inch (25 mm by 102 mm) (nominal), spaced not more than 4 feet (1219 mm) on center.

4. Design loads as applicable.4.1. Top chord live load (as determined from Section R301.6).

Steel Roof Framing. Review changes if applicable.

Roof Assemblies. Review changes if applicable.

R802.10.2.1 Applicability limits. The provisions of this section shall control the design of truss roof framing when snow controls for buildings not greater than 60 feet (18 288 mm) in length perpendicular to the joist, rafter or truss span, not greater than 36 feet (10 973 mm) in width parallel to the joist span or truss, not greater than two stories in height with each story not greater than 10 feet (3048 mm) high, and roof slopes not smaller than 3:12 (25-percent slope) or greater than 12:12 (100-percent slope). Truss roof framing constructed in accordance with the provisions of this section shall be limited to sites subjected to a maximum design wind speed of 110 miles per hour (49 m/s), Exposure A, B or C, and a maximum ground snow load of 70 psf (3352 Pa). Roof snow load is to be computed as: 0.7 pg.

R802.10.3 Bracing. Trusses shall be braced to prevent rotation and provide lateral stability in accordance with the requirements specified in the construction documents for the building and on the individual truss design drawings. In the absence of specific bracing requirements, trusses shall be braced in accordance with the Building Component Safety Information (BCSI 1-03) Guide to Good Practice for Handling, Installing & Bracing of Metal Plate Connected Wood Trusses.

R806.3 Vent and insulation clearance. Where eave or cornice vents are installed, insulation shall not block the free flow of air. A minimum of a 1-inch (25 mm) space shall be provided between the insulation and the roof sheathing and at the location of the vent.R806.4 Conditioned attic assemblies. Unvented conditioned attic assemblies (spaces between the ceiling joists of the top story and the roof rafters) are permitted under the following conditions:1. No interior vapor retarders are installed on the ceiling side (attic floor) of the unvented attic assembly.2. An air-impermeable insulation is applied in direct contact to the underside/interior of the structural roof deck. “Air-impermeable” shall be defined by ASTM E 283. Exception: In Zones 2B and 3B, insulation is not required to be air impermeable.3. In the warm humid locations as defined in Section N1101.2.1:3.1. For asphalt roofing shingles: A 1-perm (5.7 × 10-11 kg/s m2 Pa) or less vapor retarder (determined ⋅ ⋅using Procedure B of ASTM E 96) is placed to the exterior of the structural roof deck; that is, just above the roof structural sheathing.3.2. For wood shingles and shakes: a minimum continuous 1/4-inch (6 mm) vented air space separates the shingles/shakes and the roofing felt placed over the structural sheathing.4. In Zones 3 through 8 as defined in Section N1101.2, sufficient insulation is installed to maintain the monthly average temperature of the condensing surface above 45°F (7°C). The condensing surface is defined as either the structural roof deck or the interior surface of an air-impermeable insulation applied in direct contact with the underside/interior of the structural roof deck.“Air-impermeable” is quantitatively defined by ASTM E 283. For calculation purposes, an interior temperature of 68°F (20°C) is assumed. The exterior temperature is assumed to be the monthly average outside temperature.

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R301.1 Design. Buildings and structures, and all parts thereof, shall be constructed to safely support all loads, including dead loads, live loads, roof loads, flood loads, snow loads, wind loads and seismic loads as prescribed by this code. The construction of buildings and structures shall result in a system that provides a complete load path capable of transferring all loads from their point of origin through the load-resisting elements to the foundation.

R301.2.1.1 Design criteria. Construction in regions where the basicwind speeds from Figure R301.2(4) equal or exceed 110 miles per hour (177.1 km/h) shall be designed in accordance with one of the following:

R301.2.1.2 Internal pressure.Windows in buildings located in wind borne debris regions shall have glazed openings protected from windborne debris or the building shall be designed as a partially enclosed building in accordance with the International Building Code. Glazed opening protection for windborne debris shall meet the requirements of the Large Missile Test of ASTM E 1996 and of ASTM E 1886 referenced therein.

R301.2.2.2.2 Irregular buildings. Concrete construction complying with Section R611 or R612 and conventional light-frame construction shall not be used in irregular portions of structures in Seismic Design Categories C, D1 and D2. Only such irregular portions of structures shall be designed in accordance with accepted engineering practice to the extent such irregular features affect the performance of the conventional framing system. A portion of a building shall be considered to be irregular when one or more of the following conditions occur:

b. No storage with roof slope not over 3 units in 12 units.

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R302.1 Exterior walls. Exterior walls with a fire separation distance less than 3 feet (914mm)shall have not less than a one-hour fire-resistive rating with exposure from both sides. Projections shall not extend to a point closer than 2 feet (610 mm) from the line used to determine the fire separation distance.Exception: Detached garages accessory to a dwelling located within 2 feet of a lot line may have roof eave projections not exceeding 4 inches. Projections extending into the fire separation distance shall have not less than one-hour fire-resistive construction on the underside. The above provisions shall not apply to walls which are perpendicular to the line used to determine the fire separation distance.Exception: Tool and storage sheds, playhouses and similar structures exempted from permits by R105.2 are not required to provide wall protection based on location on the lot. Projections beyond the exterior wall shall not extend over the lot line.

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3. Not more than 50 percent of the required floor area of a room or space is permitted to have a sloped ceiling less than 7 feet (2134mm) in heightwith no portion of the required floor area less than 5 feet (1524 mm) in height.

[B] R308.1 Identification. Except as indicated in Section R308.1.1, each pane of glazing installed in hazardous locations as defined in Section R308.4 shall be provided with a manufacturer's or installer's label, designating the type and thickness of glass and the safety glazing standard with which it complies, which is visible in the final installation. The label shall be acid etched, sandblasted, ceramic-fired, embossedmark, or shall be of a type which once applied cannot be removed without being destroyed.Exceptions:1. For other than tempered glass, labels may be omitted provided the building official approves the use of a certificate, affidavit or other evidence confirming compliance with this code.2. Tempered spandrel glass may be identified by the manufacturer with a removable paper label.

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R317.1 Two-family dwellings. Dwelling units in two-family dwellings shall be separated from each other by wall and/or floor assemblies having not less than 1-hour fire-resistance rating when tested in accordance with ASTM E 119. Fire-resistance-rated floor-ceiling and wall assemblies shall extend to and be tight against the exterior wall, and wall assemblies shall extend to the underside of the roof sheathing. Exception: A fire resistance rating of 1/2 hour shall be permitted in buildings equipped throughout with an automatic sprinkler system installed in accordance with NFPA 13.

R317.2.1 Continuity. The common wall for townhouses shall be continuous from the foundation to the underside of the roof sheathing, deck or slab and shall extend the full length of the common wall including walls extending through and separating attached accessory structures.

R319.1 Location required. In areas subject to decay damage as established by TableR301.2(1), the following locations shall require the use of an approved species and grade of lumber, pressure treated in accordance withAWPAC1,C2,C3,C4,C9, C15, C18, C22, C23, C24, C28, C31, C33, P1, P2 and P3, or decay-resistant heartwood of redwood, black locust, or cedars.

R319.1.1 Ground contact. All wood in contact with the ground and that supports permanent structures intended for human occupancy shall be approved pressure preservatively treated wood suitable for ground contact use, except untreated wood may be used where entirely below ground water level or continuously submerged in fresh water.

R319.1.4 Wood columns.Wood columns shall be approved wood of natural decay resistance or approved pressure preservatively treated wood.Exceptions:1. Posts or columns which are either exposed to the weather or located in basements or cellars, supported by piers or metal pedestals projecting 1 inch (25.4 mm) above the floor or finished grade and 6 inches (152 mm) above exposed earth, and are separated therefrom by an approved impervious moisture barrier.2. Posts or columns in enclosed crawl spaces or unexcavated areas located within the periphery of the building, supported by a concrete pier or metal pedestal at a height greater than 8 inches (203mm) from exposed ground, are separated therefrom by an impervious moisture barrier.

R319.3 Fasteners. Fasteners for pressure preservative and fire-retardant-treated wood shall be of hot-dipped galvanized steel, stainless steel, silicon bronze or copper.Exception: One-half-inch (12.7 mm) diameter or greater steel bolts.

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R502.7 Lateral restraint at supports. Joists shall be supported laterally at the ends by full-depth solid blocking not less than 2 inches (51 mm) nominal in thickness; or by attachment to a header, band, or rim joist, or to an adjoining stud; or shall be otherwise provided with lateral support to prevent rotation. Exception: In Seismic Design Categories D1 and D2, lateral restraint shall also be provided at each intermediate support.

Spacing of fasteners on floor sheathing panel edges applies to panel edges supported by framing members and at all floor perimeters only. Spacing of fasteners on roof sheathing panel edges applies to panel edges supported by framing members and at all roof plane perimeters. Blocking of roof or floor sheathing panel edges perpendicular to the framing members shall not be required except at intersection of adjacent roof planes. Floor and roof perimeter shall be supported by framing members or solid blocking.

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of at least 1,800 pounds

R602.6 Drilling and notching - studs. Any stud in an exterior wall or bearing partition may be cut or notched to a depth not exceeding 25 percent of its width. Studs in nonbearing partitions may be notched to a depth not to exceed 40 percent of a single stud width. Any stud may be bored or drilled, provided that the diameter of the resulting hole is no greater than 40 percent of the stud width, the edge of the hole is no closer than 5/8 inch (15.9 mm) to the edge of the stud, and the hole is not located in the same section as a cut or notch. See Figures R602.6(1) and R602.6(2).Exceptions:1. A stud may be bored to a diameter not exceeding 60 percent of its width, provided that such studs located in exterior walls or bearing partitions are doubled and that not more than two successive studs are bored.2. Approved stud shoes may be used when installed in accordance with the manufacturer's recommendation.

R602.6.1 Drilling and notching of top plate.When piping or ductwork is placed in or partly in an exterior wall or interior load-bearingwall, necessitating cutting, drilling or notching of the top plate by more than 50 percent of its width, a galvanized metal tie of not less than 0.054 inches thick (1.37mm) (16ga) and 11/2 inches (38mm) wide shall be fastened to each plate across and to each side of the opening with not less than eight 16d nails at each side or equivalent. See Figure R602.6.1.

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deletedand tie-down device uplift capacity shall not be less than 3,000 pounds.

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ExceptionThe length of wall bracing in braced wall lines spaced greater or less other than 25 feet (7620 mm) apart shall be the length required byTable R602.10.1 multiplied by the appropriate adjustment factor from Table R602.10.11.

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R703.8 Flashing.Approved corrosion-resistive flashing shall be provided in the exterior wall envelope in such a manner as to prevent entry of water into the wall cavity or penetration of water to the building structural framing components. The flashing shall extend to the surface of the exterior wall finish and shall be installed to prevent water from reentering the exterior wall envelope. Approved corrosion-resistant flashings shall be installed at all of the following locations:1. At top of all exterior window and door openings in such a manner as to be leakproof, except that self-flashing windows having a continuous lap of not less than11/8 inches (28 mm) over the sheathing material around the perimeter of the opening, including corners, do not require additional flashing; jamb flashing may also be omitted when specifically approved by the building official.

R802.3.1 Ceiling joist and rafter connections. Ceiling joists and rafters shall be nailed to each other in accordance with Tables R602.3(1) and R802.5.1(9), and the assembly shall be nailed to the top wall plate in accordance with Table R602.3(1). Ceiling joists shall be continuous or securely joined where they meet over interior partitions and nailed to adjacent rafters to provide a continuous tie across the building when such joists are parallel to the rafters. Where ceiling joists are not parallel to rafters, subflooring or metal straps attached to the ends of the rafters shall be installed in a manner to provide a continuous tie across the building, or rafters shall be tied to 1-inch by 4-inch (25.4mm by 102mm) (nominal) minimum-size crossties. The connections shall be in accordance with TableR602.3(1) or connections of equivalent capacities shall be provided. Where ceiling joists or rafter ties are not provided at the top plate, the ridge formed by these rafters shall also be supported by a girder designed in accordance with accepted engineering practice.Rafter ties shall be spaced not more than 4 feet (1219 mm) on center.