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University of New HavenUniversity of New HavenID 218 Interior Systems, Materials and CodesID 218 Interior Systems, Materials and Codesby: Denis R. Ouimette AIA, OAQ, NCARBby: Denis R. Ouimette AIA, OAQ, NCARB

Lecture 005:Lecture 005:Chapter 5, Wood Light Frame ConstructionChapter 5, Wood Light Frame ConstructionReview Chapter 4Review Chapter 4Questions 1- 3 on page 141Questions 1- 3 on page 141

Reading assignment:Reading assignment:““Fundamentals of Building Construction”Fundamentals of Building Construction”Chapter 6: Exterior Finishes for Wood Light Chapter 6: Exterior Finishes for Wood Light Frame ConstructionFrame ConstructionQuestion: 1 – 7 page 225Question: 1 – 7 page 225

ID 218 Interior System, Materials and CodesID 218 Interior System, Materials and CodesChapter 5, Wood Light Frame Construction:Chapter 5, Wood Light Frame Construction:

In this chapter, you will learn:In this chapter, you will learn: Why wood light frame construction is so popular Why wood light frame construction is so popular

in North Americain North America How wood light frame construction evolvedHow wood light frame construction evolved The logic of platform frame construction, and The logic of platform frame construction, and

why it is generally preferable to balloon framingwhy it is generally preferable to balloon framing How to lay out light frame floors, walls, and roofsHow to lay out light frame floors, walls, and roofs Typical details of wood light framingTypical details of wood light framing Fire safety precautions for wood light frame Fire safety precautions for wood light frame

buildingsbuildings Why light frame construction can lead to both Why light frame construction can lead to both

good and bad architecturegood and bad architecture


5.1 Laying Out Floor Framing Design and draw ground floor framing layouts for the

buildings whose foundation plans are shown on this page and the following. Designate the size and spacing of joist used in each, and show beams, posts, doubled joists, joist hangers, blocking, and other features.

Many layouts are feasible. See Figure 5.17 through 5.20 of the text. See also guidelines provided on page 34 of the Exercises workbook. Plans that are simple in layout and that minimize joists of different depths are to be preferred over others more complex or irregular.An important point to communicate to students is that the regular 16” or 24” spacing of joists should be maintained throughout the framing plan, even when this results in occasional close spacing between a regularly spaced joist and another specially located for a partition, floor opening, or other special condition. Omitting a regularly spaced joist can result in an unsupported plywood edge, depending on the layout of plywood sheets on the deck.


5.1 Laying Out Floor Framing


5.2 Laying Out Wall Framing 1. Design and draw complete framing for

these two exterior walls, using 2x6 studs 24"o.c. (38 x 140 mm studs 600 mm o.c.) and 1x4 (19 x 89 mm) let-in diagonal bracing. Follow the procedure outlined in Figure 5.32 of the text. For door and window headers, use 2x8 (38 x 184 mm) framing or larger. Lettered arrows refer to details on the following page.See Figure 5.32 of the text. As in Problem 5.1 it is important that students appreciate the need to maintain the regular stud spacing even when occasional closely-spaced studs result.


5.2 Laying Out Wall Framing


5.2 Laying Out Wall Framing 2. Draw details A, B, C from the previous page in

the space below. See Figures 7.18 and 7.19 in the text for 2 x 6 framing detail examples.


5.3 Working With Pitched Roofs 1. Study the two examples below, then draw roof

plans and thumbnail perspectives of ten more ways of covering an L-shaped building with roofs at a pitch of 8/12.See Figure 5.46 of the text.


5.3 Working With Pitched Roofs 1. Study the two examples below, then draw roof plans and thumbnail perspectives of

ten more ways of covering an L-shaped building with roofs at a pitch of 8/12.

See Figure 5.46 of the text.


5.3 Working With Pitched Roofs 2. You are remodeling a 23-foot wide (7010 mm)

attic beneath a roof at 8/12 pitch. How wide a room can you create between new walls that are 5'-0" (1524 mm) high? Show calculations.See page 40 of the workbook for example roof pitch problem solutions.


5.3 Working With Pitched Roofs 2. You are remodeling a 23-foot wide (7010 mm) attic beneath a roof at 8/12 pitch.

How wide a room can you create between new walls that are 5'-0" (1524 mm) high? Show calculations.See page 40 of the workbook for example roof pitch problem solutions.

a) x = distance from outer wall to new wall: x/5’ = 8/12

b) x = ( 8/12 ) x 5’ = 7.5’ c) Width between new walls = 23’-0” – 2x

= 23’-0” – 2( 7.5’ )= 23’-0” – 15’= 8’-0”


5.3 Working With Pitched Roofs 3. If you made the room in the problem above 11'

(3353 mm) wide, how high would the walls be? Show calculations.

a) Width between new walls: 11’-0” = 23’-0” – 2x b) x = (23’ – 11’)/2 = 6’-0” c) h = height: h/6’ = 8/12 d) height = ( 8/12 ) x 6’ = 4’-0”


5.3 Working With Pitched Roofs 4. What is the widest balcony that can be built in

the building shown to the right while maintaining a minimum headroom above the balcony of 6'-6" (1420 mm)? Show calculations.

a) 7’-6” + 6’6” = 14’-0” b) Rise of roof to balcony edge: 14’ – 8’ = 6’ c) x = distance from outer wall to balcony edge:

10/12 = 6’/x; x = 7.2’ d) Width: 15.33’ – 7.2’ = 8.13’ = 8’-1 1/2”


5.4 Designing Roof Framing To the right is the ground floor plan of a vacation

cottage. The Dining Area and Kitchen should have a ceiling height of 7’-6” (2286 mm). The Loft floor is 12” (305 mm) thick, and the Loft should have a minimum headroom of 6’-8” (2032 mm). The Living Room should be a dramatic room that rises to the sloping underside of the roof framing.More than one solution is possible.

1. In the space below, draw a small freehand perspective of a design for a roof for this cottage. The roof may consist of any number of planes, but all must slope at the same pitch, which may not be less than 6/12.


5.4 Designing Roof Framing 1. In the space below, draw a small freehand perspective of a design for a roof for this

cottage. The roof may consist of any number of planes, but all must slope at the same pitch, which may not be less than 6/12.


5.4 Designing Roof Framing 2. Complete the section drawing above to indicate

how your roof design looks when cut at the section line indicated on the Floor Plan. Show the numerical pitch of the roof and give all wall heights and headroom clearances.


5.4 Designing Roof Framing 2. Complete the section drawing above to indicate how your roof design looks when cut

at the section line indicated on the Floor Plan. Show the numerical pitch of the roof and give all wall heights and headroom clearances.


5.4 Designing Roof Framing 3. Complete the roof framing plan below in

accordance with your roof design. Use rafters spaced 24" (600 mm) o.c. assume that the rafters can span no more than 12'-0“ (3660 mm) in plan, and that one or more wood beams, as Indicated on your plan, may be used to support rafters. No rafters may rest on the chimney.See Figures 5.47 and 5.52 for sample roof framing plans.


5.4 Designing Roof Framing 3. Complete the roof framing plan below in accordance with your roof design. Use

rafters spaced 24" (600 mm) o.c. assume that the rafters can span no more than 12'-0“ (3660 mm) in plan, and that one or more wood beams, as Indicated on your plan, may be used to support rafters. No rafters may rest on the chimney.

See Figures 5.47 and 5.52 for sample roof framing plans.


Review Questions:

1. Draw a series of very simple section drawings to illustrate the procedure for erecting a platform frame building starting with the foundation and continuing with the ground floor, the ground-floor walls, the second floor, the second-floor walls, and the roof. Do not show details of the connections but simply represent each plane of framing as a heavy line in your drawing.


Review Questions:

1.Draw a series of very simple section drawings to illustrate the procedure for erecting a platform frame building starting with the foundation and continuing with the ground floor, the ground-floor walls, the second floor, the second-floor walls, and the roof. Do not show details of the connections but simply represent each plane of framing as a heavy line in your drawing.

[The sequence of steps in erecting a light wood frame structure are illustrated beginning with Figure 5.3 and continuing intermittently through Figure 5.51.]


Review Questions:

2. Draw from memory the standard detail sections for a two-story platform frame dwelling. Hints: The easiest way to draw a detail section is to draw the pieces in the order in which they are put in place during construction. If your simple drawings from Question 1 are correct, and if you follow this procedure, you will not find this question so difficult.


Review Questions:

2. Draw from memory the standard detail sections for a two-story platform frame dwelling. Hints: The easiest way to draw a detail section is to draw the pieces in the order in which they are put in place during construction. If your simple drawings from Question 1 are correct, and if you follow this procedure, you will not find this question so difficult.[Most of the information needed to answer this question can be taken from Figure 5.2. Additional figures interspersed through the series of figures referenced above provide more detailed information.]


Review Questions:

3. What are the differences between balloon framing and platform framing? What are the advantages and disadvantages of each? Why has platform framing become the method of choice?


Review Questions:

3. What are the differences between balloon framing and platform framing? What are the advantages and disadvantages of each? Why has platform framing become the method of choice?

In balloon framing, the studs run in one piece from the sill to the rafter plate, whereas in platform framing, the studs are interrupted by the floor platforms. Balloon framing has less vertical shrinkage from drying out of the wood, while platform framing is easier and safer to erect, uses shorter lengths of lumber for studs, and is automatically firestopped, for which reasons it has become the method of choice.


Review Questions:

4. Why is firestopping not usually required in platform framing?


Review Questions:

4. Why is firestopping not usually required in platform framing?

Platform framing is automatically firestopped at each floor by the double top plate.


Review Questions:

5. Why is a steel beam or glue-laminated wood beam preferred to a solid wood beam preferred to a solid wood beam at the foundation level?


Review Questions:

5. Why is a steel beam or glue-laminated wood beam preferred to a solid wood beam preferred to a solid wood beam at the foundation level?

A wood beam under the ground floor of a platform frame will probably dry and shrink, allowing the floor to tilt, while a steel beam will not. A glue laminated wood beam is an acceptable substitute for a steel beam because it is made of thoroughly seasoned wood and will be fairly stable dimensionally.


Review Questions:

6. How is a platform frame building braced against wind and earthquake forces?


Review Questions:

6. How is a platform frame building braced against wind and earthquake forces?

A platform frame building is braced laterally by let-in diagonal bracing at the corners, by rigid sheathing such as plywood panels, or by diagonal sheathing boards.


Review Questions:7. Light framing of wood is highly combustible. In what different ways does a typical building code take this fact into account?

Most importantly, building codes restrict the height and size of buildings constructed of wood light frame, to keep occupant loads low and escape routes short. Occupant escape is also facilitated by smoke and heat alarms, and by the requirement for bedroom windows of a size sufficient to permit the emergency passage of residents and firefighters. For a few types of occupancy, wood light frame construction is not permitted at all. Building codes also encourage (and in many specific instances require) the protection of the wood frame with fire-resistant materials such as gypsum board or plaster. Increasingly, automatic sprinkler systems are becoming a requirement for types of wood frame buildings.


Chapter 5 Web Links www.cwc.caCanadian Wood Council www.finehomebuilding.comFine Homebuilding Magazinewww.jlconline.comJournal of Light Construction Magazinewww.nahb.com National Association of Home Builderswww.wood.ca Wood Design & Building Magazine

http://www.cwc.ca/

http://www.finehomebuilding.com/

http://www.jlconline.com/

http://www.nahb.com/

http://www.wood.ca/

University of New HavenUniversity of New HavenID 218 Interior Systems, Materials and CodesID 218 Interior Systems, Materials and Codesby: Denis R. Ouimette AIA, OAQ, NCARBby: Denis R. Ouimette AIA, OAQ, NCARB

To do for next class:To do for next class:

Reading assignment:Reading assignment:““Fundamentals of Building Construction” Fundamentals of Building Construction” Chapter 6Chapter 6Exterior Finishes for Wood Light Frame ConstructionExterior Finishes for Wood Light Frame ConstructionQuestion: 1 – 7 page 225Question: 1 – 7 page 225

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wood light frame buildings

codes chapter

light frame floors

wall framing

interior systems

complete framing

framing plan

floor framing design