csr hebel residential wall system design part 1

Design GuideResidential Walls

Designing for Future Living

HBL740-RWS Sept 2003

CSR™ HEBEL® RESIDENTIAL WALL SYSTEMS 2

Contents1.0 Introduction 32.0 Benefits of the Residential Wall System 43.0 Design 6

3.1 Component Inventory – screws, tophats, panels, tools 63.2 Residential Wall Systems Design Guidelines 93.3 100RWS Design Guidelines 113.4 Building Setout 153.5 Footings 173.6 Control Joints 173.7 Fire Rated Construction 183.8 Windows 183.9 Two-Storey Construction 183.10 Attached Garages 193.11 RWS Retrofit 193.12 Design and Detailing for Termite Resistance 19

4.0 Construction 204.1 Installation – 75RWS panels 204.2 Installation – 100RWS panels 224.3 Bracing of the Building 234.4 Installation of Services 244.5 75RWS panels Checklist 254.5.1 Checklist – Designer 254.5.2 Checklist –Builder 264.5.3 Checklist –Installer 274.5.4 Checklist –Inspector/Supervisor 284.6 Retrofit Construction 29

5.0 Construction Details 315.1 75RWS panels 315.2 100RWS panels 425.3 Two-Storey Construction 505.4 Two-Storey Additions 555.5 Retrofit Details 59

6.0 Estimating 636.1 Estimating Process 636.2 Worked Example 66

7.0 Coatings 677.1 Introduction 677.2 Wall Preparation 677.3 Sealing 677.4 Meshing Panel Joints 687.5 Recommended Systems 68

8.0 Fixings 69

9.0 Handling & Installation 70Guidelines 9.1 Introduction 70

9.2 Panel Delivery 709.3 Layout 709.4 Layout Drawings 709.5 Site Preparation 709.6 Lifting 709.7 Bracing 709.8 Fixings 70

Appendix A: Sample Panel Installation Specification 72Appendix B: Sample Coating Specification 74Appendix C: Testing and Appraisals 75

Acoustic Opinion for External Walls, PKA Consulting,August 1998 75Certificate of Test: No. 555 76Certificate of Test: No. 595 77

Notes 78

CSR™ Hebel®

CSR™ Hebel® is 100% owned byCSR™ Building Products Limited, one of Australia’s leading building productscompanies. CSR™ Hebel® manufacturesand markets a range of lightweightAutoclaved Aerated Concrete (AAC)blocks, reinforced panels, cladding andlintels for use in the housing andcommercial construction industry.CSR™ Hebel® also sells complimentarymortars, tools and accessories.

In 1989, CSR™ became involved withHebel® and established the Australianoperation. Since then, CSR™ Hebel®

has won wide acceptance as aninnovative and environmentally friendlybuilding material due to its speed ofconstruction, excellent thermal/fire/acousticproperties and its design versatility.

Design Overview

As environmental consciousness andsocial responsibility increases, CSR Hebelis striving to exceed these ideals and setnew standards in building materials andresidential living.

Designed for inner comfort

With CSR Hebel wall and floor solutions,clients can enjoy a comfortable interiorin their home, and be comfortable withtheir choice for the environment.Manufacture of CSR Hebel materialsuses a small fraction of the energy andnatural resources used in manufacturingconventional masonry, producing almostno waste or by-products. And Hebel’shighly efficient insulation saves power in heating or cooling the home.

Designed for inner peace

CSR Hebel wall and floor solutions help you create a tranquil inner space.We have worked closely with acousticexperts and testing authorities toengineer inherently superior acousticsfrom our wall and floor systems.They

create a sound barrier to external noiseand from other rooms within the home.

Designed for peace of mind

Although it’s remarkably lightweight,

CSR Hebel is solid and durable.

CSR Hebel panels are reinforced with

steel for extra strength. CSR Hebel is also

extremely fire-resistant and immune to

termite attack.

Designed to save

As they’re lightweight, CSR Hebel

materials are quick to assemble, saving

building time and costs. They also minimise

the need for supporting materials, saving

budget resources and energy.

Use CSR Hebel for BetterFramed Construction

■ Using CSR Hebel wall panels for your

framed construction provides you with

cost savings and greater floor space for

the same building dimensions.

■ CSR Hebel panels are faster to install

than bricks, saving on building costs.

■ CSR Hebel products are lightweight,

reducing the structural load on the

frame and its design requirements

for supporting building materials.

■Their low weight makes CSR Hebel

panels ideal for use in difficult

applications such as sloping sites.

■ An external wall of CSR Hebel panels

is steel-reinforced, solid and secure.

■ CSR Hebel panels have better thermal

efficiency than brick veneer or even

double brick walls, resulting in

reduced heating and cooling costs.

Further thermal efficiency may be

achieved by adding insulation to the

frame cavity.

■ CSR Hebel is fire-resistant, with

a fire rating of at least three hours.

■ CSR Hebel walls and floors provide

better acoustic insulation to brick,

whilst taking less space.

CSR Hebel systems forFramed Construction

Residential Wall System

The CSR Hebel Residential Wall System(RWS) is designed for homes built usingeither timber or steel framing and canbe used in new dwelling construction,extensions or re-cladding.

The system consists of 75mm thick,steel-reinforced CSR Hebel RWS panels,fixed vertically to horizontal battensattached to the load-bearing frame. Forquick, clean construction, RWS panelscome in lengths of 2,400mm, 2,700mmor 3,000mm and widths of 300mm or 600mm.

Retrofit – an excitingopportunity

The RWS system is excellent for the retrofit or recladding of homesthat are clad in ‘fibro’, FC sheeting orweatherboard. It can be externally facefixed and site cut to suit most houses.The RWS system will provide a solid,thermally efficient wall to the dwellingwith minimal footing modifications,at a significant cost saving to usingtraditional brickwork with additionalstrip footings.

CSR™ HEBEL® RESIDENTIAL WALL SYSTEMS3

1.0 Introduction

Plastic shrink wrap cover

Metalstrapping

Support pallet

HandlingGuidelines

Han

dlin

gG

uide

lines

75RWS panels as delivered to site

2.0 Benefits of the Residential Wall System


Speed

■ With the CSR Hebel Residential Wall System(RWS), your home will reach lock-up stage sooner.The installation of CSR Hebel RWS panels is veryfast, especially on purpose-designed houses.

■ Any competent tradesperson can easily install RWS.Two people can install up to 100m2 of external wallin about three days.

■ The modular design of the dwelling minimises waste.

■ A standard panel weighs about 75kg, which twopeople can position. No cranes or cement mixersare required.

Space

■ The RWS gives you great freedom in designing yourhome, and you can customise the style by applyingcoloured and textured coatings to the panels.

■ A thinner external wall results in greater internal living space and design flexibility.A 55mm reduction in external wall thickness can provide about 2% extrainternal space for the same external dimensions.

Solidity

■ CSR Hebel is a solid choice. It’s extremely strong, and each RWS panel is steel reinforced.

■ With a fire rating of at least three hours you can’t beat CSR Hebel.

■ CSR Hebel offers excellent protection against vermin and does not provide a food source termites.


Lower Energy Costs

■ As with all CSR Hebel products, the RWS has excellent thermal properties. This feature results in lower heating and cooling costs

at no additional building expense.

CSR Hebel RWS Legend

Relevant Documents

CSR HebelRWS panels

Timber beam

Concrete Steel

■ CSR Hebel Technical Manual – No.HBL 700, June 2001

■ CSR Hebel PowerpanelTM, Design Calculations, May 1995,August 2000

■ CSR Hebel Powerwall, Design Calculations, June 1995

■ AS/NZS 1170 Series – Structural Design Actions

■ AS 1684 – 1999 Residential timber-framed construction

■ AS 1720.1 – 1997 Timber Structures Code –Part 1: Design Methods

■ AS 2870 – 1996 Residential Slabs and Footings

■ AS 3623 – 1993 Domestic Metal Framing

■ AS 3660.1 – 2000 Termite Management – New building work

■ AS 3566 – 2002 Series – Self-drilling screws for thebuilding and construction industries

■ ABCB Guideline Document – Durability in Buildings: 2003

■ AS/NZS 2312: 2002 Guide to the protection of structuralsteel against atmospheric corrosion by the use ofprotective coatings

■ ISO 9223: 1992 – Corrosion of metals and alloys – corrosivity of atmostpheres – classifiaction

■ AS2331 Series


3.0 Design3.1 Component Inventory

Table 3.1 Screws Specification

Note: Design Capacity = (Average - 2 x Std Dev) / Safety Factor, Safety Factor = 3.0 (for pullout design capacity) and 5.0 (for shear design capacity). The pullout and shear values in the above table have been provided by the screw manufacturer or determined by testing carried out by CSR Hebel through registered testing laboratories such as ETRS.

Photo 1 Photo 2 Photo 3 Photo 4

Durability of ComponentsIt is the responsibility of the building designer to ensure that the components, such as screws, tophat battens,and other steel components, have the appropriate corrosion protection to suit the required project design life.


Note: BTM is the smooth face.

Bars: 4x5mmø longitudinal & 5-6 transverse bars dependingon panel length.

Tolerance: The width andthickness of the panels aremanufactured to a tolerance of + or - 1.5mm.

Typical Cross Section

Typical Cross Section of 75RWS panel

Table 3.2 Tophat Specification

Note: Batten dimensions are nominal and may vary depending on the source. Suitability of tophat alternatives to be approvedby the tophat manufacturer.

Note: Mass of 75RWS panels are based on an average product working density of 670kg/m3 (30% moisture content by weight, average dry density of 510 kg/m3, characteristic compressive strength of 2.5MPa).

Mass of 100RWS panels are based on an average product working density of 720kg/m3 (30% moisture content by weight, average dry density of 550kg/m3, characteristics compressive strength of 2.5MPa.

Table 3.3 Panel: Sizes & Weights


Tools & Equipment

The tools required to assist in theinstallation of the RWS panels that maybe purchased through CSR Hebel are:

1. Mixing Bucket

2. Stirrer

3. Notched Trowels

4. Sanding Float

5. Panel Lifters

6.Anti Corrosion Agent

Extra equipment will also be requiredand includes the following:

■ Power drill (clutch driven)

■ Power saw with metal or diamond-tipped cutting blades

■ Dust extraction system

■ Sockets for screws

■ Safety equipment such as goggles and face mask, used when site cutting the panels.

20

450

100

4012012012050

Typical Cross Section of 100RWS panel

PERMISSIBLE

Note: BTM is the smooth face.

Bars: 4x5mmø longitudinal & 10 transverse bars in each face.

Tolerance: The width and thickness of the panels are manufactured to atolerance of + or - 1.5mm.

Note:

• Capacities determined for permissible wind load producing a panel deflection of span/180;

• 75RWS panel spans between tophats;and

• 100RWS panel spans between the top and bottom fixing points.

Table 3.4 Panel Loading CapacityLateral Permissible Wind Loads


3.2 Residential Wall System Design Guidelines

Introduction

This section provides the basicinformation on the installation of theResidential Wall System. The system hasbeen assessed by the Australian BuildingSystem Appraisal Council (ABSAC) and a summary of their technical opinion isincluded in the appendices. The principleson which the design is based include:

a) The lateral wind loads applied to thepanels are directly transferred to the

stud frame, which should be designedin accordance with the relevantAustralian Standards for the imposedloads. The frame should be designedfor all bracing and hold-downrequirements.

b) The design of the stud frame shallconsider the weight of suspendedpanels (such as the upper storey oftwo-storey construction).

c) The system is not considered ascavity construction, as the tophatclearly bridges the cavity, hence thedetails show the necessity of sealingthe windows and door frames, aswell as applying a water resistantexternal coating.

d) The system specifications vary withwind load. The notation used inAS1684-1999 Residential timberframed construction has been adopted.

e)The localised effects of wind aroundcorners of buildings have beenconsidered in the design and includedin the tables. The extent of this effect is discussed towards the end of thissection.

The tables below set out the installationcriteria for the system, and are based on design calculations using the materialspecifications detailed in Section 3.1.The following flow chart should beused as a guide for the design process:

Flow Chart for Design Process

Stud capacityand spacing


Criteria for Corner Panels

Due to the increase of wind load around the corners of buildings, extratophats and screws may be necessary(N3 and greater) for a distance of 20%of the wall length in each direction fromthe corner.

Tables 3.5 to 3.7 identify the installationcriteria in these areas, in the columnstitled Corner Panels.

Cyclonic Loading Effects

The Residential Wall System has beentested at the Cyclonic Loading Station

in Townsville to satisfy the requirementsof AS1170.2 – 1989 Section 2.6. Thepullout capacity of the screw into theback of the CSR Hebel panel is thecritical element in the design. The resultsfrom the cyclic testing showed that thesystem, in particular the pullout load of

Note: For fire rated construction a minimum of 3 screws per middle tophat is required (refer to section 3.7). Type of screw used is the 14-10 x 65mm Hex Head Type 17 screw, fixed from inside the building, or 14-10 x 100mm MP Bugle Head Battenscrew, fixed from outside the building (as per Table 3.1).

Note: 1. For the upper storey panels in two storey construction, a minimum of four tophats will be required.

2.Additional tophats will be required below all window openings and above openings if a panel or sill block is to be installedin this location. In either case, the maximum spacing of the tophats should be maintained as set out in Table 3.6 below.

Table 3.5 Number of Tophats (Horizontal)

Table 3.6 Maximum Spacing of Tophats (mm)

Table 3.7 Number of Screws Per Panel for Each Tophat Location


the screw, is unaffected by the cyclicloading.The detailing presented in thismanual is satisfactory for cyclonic areas.

Coastal Regions

CSR Hebel RWS panels may be used in coastal regions. It is the responsibility of the building designer to ensure theitems specified will maintain their strengthand integrity for the project design life.For guidance, refer to the followingdocuments when assessing durability:

• ABCB Guideline Document –Durability in buildings: 2003

• AS/NZS 2312: 2002 – Guide to theprotection of structural steel againstatmospheric corrosion by the use of protective coatings.

• ISO 9223: 1992 – Corrosion of metals and alloys – Corrosivity ofatmospheres – Classification.

• AS3566: 2002 – Self drilling screws for the building and constructionindustries.

• AS2331 Series.

Reference to AS3566 – 1988 shouldalways be adhered to when selecting thescrews corrosion resistance classification.

Timber Treated Frames

The tophat section specified in thismanual can ONLY be used on untreatedand dry timber frames. CCA treatedpine or green timber frames have adeleterious effect on the tophatcoatings which can lead to corrosion.Where timber is CCA treated provide

a barrier between tophat and timbermember. Refer to screw manufacturerfor appropriate screw specification forthis application.

3.3 100RWS panelDesign Guidelines

Introduction

This section provides the basicinformation on the installation of the100RWS system. The principles onwhich the design is based include:

(a) The 100mm thick panel has beendesigned to resist all lateral windloads without the need for a studframe.The load reactions aretransferred to the top and bottomsupports via the fixings detailed in the table below.

(b) The walling system has beendesigned for use in N2 and N3

non-cyclonic wind regions. It isrecommended that the 75RWSsystem be used in the higher wind regions.

(c) The vertical dead and live loads on the roof are taken by piers whichsupport a perimeter beam on whichall the roof framing/trusses bear. Theuplift forces are taken by the wallsystem itself for N2 regions and bysteel SHS posts for the N3 regions.

(d) The localised effects of wind aroundthe corners of the building have alsobeen considered in the design of the100RWS system and are included inthe following tables.

Tables 3.8 and 3.9 set out the installationcriteria for the system, based on designcalculations using the material specificationsdetailed in Section 3.1. The followingflow chart should be used as a guide for the design process.

Typical corner panel areas


Note: • The Spacing of Fixings applies for both single and double garages.

• Dynabolts can only be used for N2 Tiled Roof as this type of fixing has not been designed for the cyclic loading associatedwith uplift, hence the M8 Trubolt should be used for N2 Sheet and all N3 conditions.

Connection detail for corner panels

Detail for N3 Corner Panels

■ M8 galvanised bolt and 40x40x3square washer fixed through thecentre of the corner panels only

■ Allow to recess the large washer20mm maximum into the externalface of the panel

■ Refer to Section 3.2 for furtherinformation on the corner panels

Note: • Load width based on 3.5m for a double garage and 2.0m for a single garage;

• *Identifies the need for an additional M8 bolt and 40x40mm washer through each panel (refer to the detail below); and,

• As per Table 3.1, the fixing used is the 14-10 x 65mm Hex Head Type 17 screw.

Table 3.8 Fixing of Garage Angle to the Slab

Table 3.9 Fixing of 100 RWS panels to Garage Angle


Installation of Piers

The installation of 100mm thick piers is required each side of the garage door opening. These piers can be site-cut to a minimumwidth of 200mm from a stock 100RWS panel. The piers are used to support the installation of a horizontal 100mm thick panelacross the head of the opening, as per Details 5.2.2/3.

Piers are also required along the side walls of the garage to support the perimeter beam.Table 3.11 below sets out the criteria ofthese piers for the different wind categories, while Table 3.12 specifies the installation criteria for the SHS post used in N3 regions.

Note: • Load width based on 3.5m for a double garage and 2.0m for a single garage.

• As per Table 3.1, the fixing used is the 14-10x100 Bugle Head Batten screw.

Note: • The pier capacities and spacings shown allow for the load of a tile roof spanning over a 6m wide double garage.

• The beam around the top of the wall which spans between the piers will need to be in accordance with AS1684 – 1999 Residential Timber-Framed Construction or to Structural Engineers’s approval.

• The 75RWS panel piers and those around the garage door should be packed where necessary to the undersideof the beam above with FC sheeting or other non compressible material, when necessary.

Table 3.10 Fixing of 100RWS panels to Garage Beam

Table 3.11 Piers along the Side Walls


Detail for SHS Posts in Garage

■ Refer to Table 3.12

■ 8mm steel angle used typically

■ Top fixing bolt is installed through full thickness of beam

Bracing Capacity of 100RWS panels

In some cases the side wall of the garage is required to resist aracking wind load. Table 3.13 below provides the bracing capacityfor a number of panels.The theory associated with this table takesinto consideration the following items:

■The self weight of the panels

■The capacities of the various fixing systems

■ Assumes 3 screws per panel are installedthrough the garage angle at the base

■ Assumes the garage angle is fixed with Truboltsat a maximum spacing of 600mm

Note: Each section must contain full height panels that are fully glued with Thin Bed Adhesive, and contain no openings or control joints.

Table 3.12 Fixing of SHS Post (N3 only)

Table 3.12 Fixing of SHS Post (N3 only)


3.4 Building Setout

CSR Hebel RWS is principally designed for modular construction.The full benefit of savings in time andcost will be fully realised when thehouses are designed to suit a 300mmmodule. In principle, thoughtful setouton the drawing board will minimise the site-cutting of panels, which is timeconsuming and wasteful, as comparedto the installation of stock panels.

(A) Vertical Dimensions

A few important criteria affect thevertical setout of the building:

(i) A stepdown from the main slab is required for 75RWS panelinstallation. The stepdown should begreater than 50mm deep and amaximum of 95mm wide.

The actual depth of the stepdown isdependent on the height of the eavesabove the slab level, and is rarely greaterthan 150mm.

The following quick check can be usedto confirm the stepdown dimensions.

Example:

1. Stepdown = 2400-2200-50 = 150mm

2. Stepdown = 2700-2500-50 = 150mm.Here, 450mm widepanels will berequired over the windows whichhave a head height of 2100mm abovethe slab.

(ii) For all Residential Wall Systeminstallation the bottom of the panel must remain 75mm abovethe finished ground level (FGL).This minimum distance satisfies recommendations of the currenttermite guidelines (refer, BCA Vol. 2,3.1.3. and AS 3660.1.) The buildershould ensure that this requirementis clearly communicated to thefuture home owner.

(iii) The top of the panel should extend50mm above the eaves to preventany water running down betweenthe panel and the stud frame.Attention should be given to thedraining of the eaves.

(iv) The vertical setout and verticaldimension of the windows andother openings is not critical for RWS construction,as all the panels are site-cut toaccommodate this setout.However, if windows are installed in the garage, they must be locatedup to the underside of the eavesor to the top of the 100mmpanels, if there are panels above (ie. in a gable wall).

(v) When 2.7m or 3.0m long panelsare used, a panel can be installedhorizontally over the openings, withtheir length and width site-cut tosuit. No galvanised steel angle lintelor additional top hat is required ifno other panels are seated directlyon top of this horizontal panel. Ingables, a steel angle is required on

top of the horizontal panel oradditional tophats to the panelsover, to carry the weight of thegable panels above. Refer to Detail5.1.7 for further information.

(vi) As a guide, the following table givesthe appropriate panel lengths for avariety of possible buildingconfigurations:

Stepdown = Panel Length - EavesHeight - 50

Typical stepdown detail Typical window head detail

Typical eaves detail

FGL75

min.


(B) Horizontal Dimensions

The horizontal setout of the building is vital, as incorrect drawings lead toproblems with the frame and hence the panel installation. Please note thefollowing items which require carefulconsideration during the building design stage.

(i) Setting the building out to a 300mmor 600mm module is mostimportant. All openings should be clearly dimensioned on the plan,as well as the exact size of theopening. Although site tolerances canbe made up during the installationprocess, it is important to achieve an efficient layout on the drawingboard first.

(ii) Setting up a grid across the plan willnot help to achieve the requiredlayout, as the orientation of the panelsin each corner affects the setout.There are no rules to setting out acorner; however, be aware that a10mm control joint is normallyrequired at every corner. Thereforean 85mm offset occurs along one side.

You may choose to set a standardcorner orientation. For example, jointswill occur only in the side walls, andhence the offset will occur on these walls.

(iii) The location of all control jointsshould be noted on the drawingand a 10mm gap allowed in thedimensioning of the building. Referto Section 3.6 for guidelines on the location of control joints arounda building.

Typical modular layout of window

Typical corner detail

Typical control joint detail


(iv) To assist in maintaining the modularsetout of the building, windowsshould be ordered to suit the300mm module. However, if thelength of panel required below thesill is less than 600mm, then a sitecut horizontal panel (rather thanvertical panels) can be installedhere and hence the width of thewindow is not critical. Typically,external doors and sliding doorsare full height and hence theirwidth is not critical to the module,as there are no panels requiredabove or below, but it should benoted on the drawing.

While most standard window sizes do not exactly fit the 300mm module,often being 10mm greater in size,this is easily incorporated into theconstruction (Refer to Detail 5.1.4).

Additionally, a number of manufacturersare prepared to supply the windows tothe desired width with volume orders.

(v) The distance between openingsshould not be less than 300mm,obviously to suit a standard panel.With regard to splays and baywindows, the same principle applies.Note that for 45° splays, a 600mmwide panel can be site-cut to aminimum width of 270mm.

3.5 Footings

Footings for the Residential WallSystem should comply with conventional masonry veneerconstruction as specified in AustralianStandard AS 2870 – 1996. This is aminimum requirement.

Local engineering advice should alwaysbe sought, especially in areas of highlyreactive ground conditions.

3.6 Control Joints

Control joints should be spaced at amaximum of 6m centres. However localengineering advice should always prevail.

At all corners the tophat section isdiscontinuous and therefore a weaknessexists at the vertical panel joint in theselocations. Hence control joints shouldbe located at most external corners,and all internal corners. Control jointsshould also occur at the interfacebetween 75RWS and 100RWS panelconstruction and next to openings, tocomply with the maximum spacing

requirements. Refer to the drawing onDetail 5.1.8 for a typical control jointlayout around a dwelling.

The width of the control joint shouldbe between 5-10mm. During thecoating application all joints should be sealed with a backing rod and a polyurethane sealant.

For fire rated walls an approved firerated sealant should be used.

If an external corner has a full heightopening within 1200mm of the corner,then the control joint in the cornercan be repositioned to the closestedge of this opening. The panel jointat the corner should, in this case, befully glued with Thin Bed Adhesive,screwed with a maximum of 3 off 14 – 10 x 150mm Hex Head Type 17coarse threaded screws at 900mmmaximum centres and meshed acrossduring the coating application (refer to the Coating Specification).

At all control joints, the tophat should be discontinuous to allowfor the effective movement of the building at these locations.Refer to Detail 5.1.3 for a typical tophatlayout across a control joint.

Panels below window detail

Typical bay window detail Typical panel layout for window


3.7 Fire RatedConstruction

The full Residential Wall System,including the frame and CSR GyprockTM

has been fire assessed by the CSIROand cleared to achieve a FireResistance Level (FRL) of 240/180/180in accordance with the Building Code of Australia (BCA), from the outside of the wall only.

This excellent result enables the RWSto be used in the following applications:

■ walls on zero line allotment blocks

■ multi-storey residential dwellings –external walls

■ commercial developments

■ infill panels

Note that in the above applications, eachpanel should be screwed as specified inthis manual, except a minimum of threescrews should be installed through themiddle tophat into each panel.

3.8 WindowsFurther to the discussion on windowsizes in Section 3.4 (B) (iv) the buildershould also ensure that the reveal size is

correct to suit the Residential WallSystem. Refer to the table on nextcolumn for recommendations:

The sizes above typically apply toaluminium framed windows. If timberwindows are being used similartolerances and guidelines apply. Refer to Detail 5.1.5 for a section through the sill of a timber window.

In the garage, 100RWS panels are used,the windows should be orderedwithout reveals.

3.9 Two-StoreyConstruction

The use of the Residential Wall System in two-storey constructioninvolves a number of design issues thatrequire attention. In conjunction withthe following, refer to the ConstructionDetails in Section 5.3 & 5.4.

Note, when panels are suspended fromthe stud frame the project engineershall design the frame to support theweight of the panels.

Steel Frame Construction

Two storey construction suits a steelframed dwelling as the weight of theupper storey panels bear directly on the lower storey panels. Note, lowerstorey panels are to bear on the slab.However consideration should begiven to the sectional size of thelintels over openings on the lowerstorey. As the details reveal, only an‘Ableflex’ joint is required at thehorizontal panel junction between the upper and lower panels.

Timber Frame Construction

In contrast, the upper storey panelscannot rest on the lower storey panels in timber framed dwellings, due to the

effects of timber shrinkage. Movementsin the order of 25mm can occur in atwo storey timber frame with a timberfirst floor. The fixing method used in the75RWS system does not allow for thisextent of differential movementbetween the external skin and thetimber frame.

It is therefore recommended that theupper storey panels be installed 35mmclear of the lower storey panels.During construction a temporarypacker is used to separate the panelsand is then removed after the panelshave been screwed to the tophats.The impact of this construction is toload the lower storey frame with theweight of the upper storey panels. Ineffect, an extra 55kg/m2 (for the height of the upper panels) is beingadded to the load already carried by the timber frame. The loadapproximates1.3 kN/m (2.4m panel).

To simplify the design implications of thisextra load, it is recommended to add anextra 1.5m of tributary width for a90kg/m2 Tile Roof load (for 2.4m longupper panels) for the design of thelower storey frame and timber lintels,when using AS1684 -1999.

The support of the full weight of theupper storey panels can be adequatelysupported by the tophat system.A full design using a safety factor of five hasbeen undertaken and checked toconfirm this. The only requirement isthat a minimum of four tophats beused to support the suspended panels,and the panels screw fixed as per Table 3.7.

Design Tip

In order to reduce the load of the upper storey panels and make installation easier, the lowerstorey panels should be specified as2700mm/3000mm in length and the


upper storey panels as 2400mm inlength. The vertical dimensions can be adjusted to suit.

A garage is considered ‘attached’ whenat least one full side of the garage isconnected to the main dwelling.

3.10 Attached GaragesThe use of the 75RWS panels is notpossible in attached garages if a studframe is not included for the lateralsupport of the panels. For this application100RWS panels are required. Thesepanels can adequately span 2.6mvertically between supports with amaximum applied lateral wind load of 2.58 kPa.

Piers along the side walls of the garageshould be installed to support a headtimber beam sized in accordance withAS1684 – 1999 or to StructuralEngineers detail. Refer to Tables 3.11and 3.12 in Section 3.3 for additionalinformation on the type and installationof these piers.

Section 3.3 provides information on the fixing requirements of this system.Section 4.2 gives a detailed constructionsequence and Section 5.2 incorporatesthe construction details. Refer to theCSR Hebel web page or contact thetechnical department for further details.

3.11 RWS RetrofitExisting dwellings clad with FC or ACsheeting and weatherboard are easilyre-clad with 75RWS panels to provide a solid external wall withexcellent thermal insulation.

However, the original design of thehouse frame would not have includedan allowance for the weight of thepanels. Therefore the panels need torest on a ‘shelf ’ angle (such as 100x75x8galvanised angle) at the base of the wall.The angle should be installed to spanbetween the piers or supports at amaximum spacing of 2.0m. This anglewill also assist during the constructionprocess. For further details refer tosection 4.6. The project engineer shall certify the structural adequacy of the foundations.

The additional panel weight may resultin some footing settlement. The extent of the movement and its effect on theinternal wall linings is impossible to predict.The builder should consider allowing forsome rectification of possible hairlinecracks appearing in the internal walls.

Control joints between the panelsshould be incorporated at all cornersand at no greater than 4.2m centres.In either case, local engineering adviceshould always prevail.

If existing two-storey dwellings are tobe retrofitted with 75RWS panels,there may not be a need to provide a gap between the lower and upperpanels (depending on the age of thebuilding) as all the timber movementmay have taken place. The upper panelscould sit directly on the lower panelswith 50mm wide ‘Abelflex’ in the joint.

Refer to Section 4.6 & 5.5 for additionalguidelines and details for retrofittingwith RWS panels.

3.12 Design &Detailing for Termite Resistance

It is the builder’s responsibility to ensurethat all council and Australian coderequirements are fully adhered to inregard to the design of the house forpreventing termite attack.

The construction details contained in this guide do not attempt to fullyaddress the issues, due to the variationof requirements from state to state.The specific Residential Wall System is ideally suited to the exposed edgemethod of perimeter protection.


4.0 Construction4.1 Installation – 75RWS panels

■ Corner panel installed first

■ 3 screws from outside

■ Check panel orientation at corners

■ First panel vertical with level

■ Check number of screws per tophat

■ Check control joint locations

■ Fix to bottom plate

■ Cover step completely

■ Lap at corners

1. Frames and TrussesComplete

2. Fix Tophats

3. Install DPC

4. Install RWS panel

■ 2 screws/stud

■ Check number of tophats required

■ Extras under openings

■ Thin bed adhesive to vertical joints ■ Site-cutting to suit

■ Coating of exposed reinforcement

■ Check overlap at corners

■ Check detail around control joints,ensuring tophats are discontinuous at Control Joint locations


4.1 Installation – 75RWS panels (Cont.)

5. Window Detail

6. Prepare for Coating

7. Coatings

■ Panel hard against window frame ■ Weather strip down sill

■ Flashing behind panel

■ Site-cut sill with slope

■ Apply anti-corrosion agent

■ Add special feature eg. Quoins etc ■ Sand joints flush

■ Fill joints and patch any damage ■ Fill external screw holes as required

■ Seal windows

■ Seal control joints

■ Refer to specification from coatingmanufacturer for further details


4.2 Installation – 100RWS panels

3. Install DPC

4. Install RWS panels

6. Window Details

■ Fix angle to slab to specification and details

■ 65mm long Hex Head screws atbase as per specifications

■ Thin bed adhesive to joints

■ 100mm long screws at top of beam asper specifications (pre-drilling required)

■ Install 300 x 75 piers to underside of garage beam as per specifications

■ Install panel over garage door, referto details

7. Prepare for Coating

■ Refer to 4.1:6.

8. Coatings

■ Refer to 4.1:7.

■ Refer to details

■ 110mm wide DPC on top of angle

2. Install Garage Angle1. Frame/Beam andTrusses Complete

5. Install Piers


4.3 Bracing of the Building

The walls of the dwelling should bebraced using steel cross bracingwherever possible, to allow the fixing of the panels from inside the building,such as Teco speed bracing.

Ply or sheet bracing should be used on the external wall, if the walls are too short for the steel cross bracing(Refer AS 1684-1999). In this case, thefull length of the wall should be sheetedto prevent misalignment of the panels.Alternatively, localised strips of thesheeting can be fixed to the intermediatestuds, between the areas of full sheetbracing, to maintain the panel alignment.

The panels to be installed over the areasof full plywood sheeting will need to befixed from the outside of the buildingusing the 100mm long Bugle HeadBatten screw (refer to Table 3.1).

The extent of the bracing should be determined by the timber framedesigner or Structural Engineer.CSR Hebel do not recommend fixingRWS panels from the inside when sheet bracing is installed.

If sheet bracing is used over steel ortimber frame construction then increasethe length of the screw (for fixing thetophats – refer to Section 3) by thethickness of the sheet bracing.


The installation of services in the buildingis very similar to the methods currentlybeing used throughout the industry.

The gap between the panel and theframe, which nominally measures 20mm,is quite adequate to allow electricalservices to be installed as usual. Theelectrical meter box can be face fixed tothe outside of the panels, or alternatively,recessed into the stud frame through thepanels. In the latter case, appropriatesetout of the opening should also suitthe 300mm module and all sides of thebox should be sealed to the panels withan approved sealant.

With regard to plumbing services,the hot and cold water pipes can beexternally face fixed to the studs, ifnecessary.As the Residential Wall Systemis not classified as cavity construction, thisinstallation technique is satisfactory. Theonly difficulty occurs when the pipes arerun vertically. In this case the pipes mustbe mounted between the studs, so asnot to foul the horizontal installation ofthe tophats. Tophats are not to be cut to allow clearance for services.

Penetrations through the panel forservices should be neatly filled and thejoint sealed with a polyurethane sealant.

4.4 Installation of Services


4.5 75RWS panel Checklist

4.5.1 Checklist – Designer


4.5.2 Checklist – Builder

Note: It is important that the builder understands his responsibilities as outlined in the previous two checklists and refers to theconstruction details in the manual, in order to ensure that the greatest benefit is achieved through the use of the ResidentialWall System, and to avoid incurring additional costs.


4.5.3 Checklist – Installer


4.5.4 Checklist – Inspector/Superviser


4.6 Retrofit Construction

(v) Existing Frame

As the Residential Wall System panel is directly connected to the frame of the house, the qualityof the existingframe is an important consideration.If the frame is out of alignment in anyway, the final quality of the installedpanels can be affected. It may benecessary to pack the tophats to ensure a vertical and straight wall.

(vi) Structural Adequacy

We recommend consultation with a practicing structural engineer toinvestigate the structural adequacy of the existing footings and foundation to support the additional load that willbe imposed upon them after the panelshave been installed.

(iv) Subfloor Zone

The type of construction of the externalface of the house below floor level variesfrom open with piers, clad with sheetingto continuous brickwork. Considerationof the finish in this area is necessary. Thedetails in Section 5.5 show the variety ofpossible finish alternatives, some using theinstallation of panels. However, it may bedecided to keep this zone open and infillwith timber or fibre cement lattice work.

(iii) Services

A number of services are typicallymounted on the external face of thebuilding, such as down pipes, water pipesand possibly sewer pipes. The cost ofremoval and replacement (or relocation)of these items will need to beconsidered in the project budget.

(A) Preliminaries

The installation of 75RWS panels on an existing dwelling involves a number of issues that require consideration prior to commencing.

(i) Council Approval

The installation of the Residential Wall System to an existing buildingwill add a minimum of 95mm to theexternal dimensions of the building.The local council may require abuilding application to be lodged for this change in building size.

(ii) Windows

The existing windows may or may notsuit the proposed change in the dwelling’sappearance. In addition, the actualprofile of the window frame should bechecked to consider how well the panelswill butt up to the edge of the frame.A storm mould may be required tobridge a gap if the window frame doesnot extend out 20mm to pass the tophat.

These issues raise the question ofwhether or not the windows shouldbe completely replaced.


(i) Tophat Installation

If the building is sheeted with fibrecement or asbestos cement sheets,the trims and mouldings need only beremoved. The sheeting can remain fixedto the building. The tophats can bescrewed straight through the sheetinginto the studs. If the building has timbercladding, such as weatherboards, it will benecessary for this type of cladding to beremoved, prior to the installation of thetophats.

(ii) Cutting Panels

It may be necessary for more panels to be cut to size (in width) on site to fitthe geometry and setout of the dwellingthan that necessary for a new home. Inthis regard, the usual restriction applies,being a 270mm minimum width cutfrom a 600mm wide panel.

An example of where this applies is forsay, an 800mm wide section. Here thesection cannot be installed with a600mm (stock) panel and a 200mmwide (cut) panel. The correct solution is to use a 300mm (stock) panel and a 500mm wide (cut) panel. In this case,still only one site-cut panel is required.

If the distance between two openings isless than 270mm, it will be necessary toframe this section with timber, clad withFC sheeting to suit, and coat to matchthe rest of the dwelling.

Some of these setout problems may beovercome if the windows are replacedand sightly relocated to allow for the300mm module.

(iii) Installation

All the panels will need to be fixed to the tophat from the outside of thebuilding using the 100mm long BugleHead Batten screw (refer to Table 3.1).The screw should stop a maximum of5mm below the face of the panel andshould be patched prior to coating using CSR Hebel Patching Mortar or a mixture of thin bedded adhesive and dust (created from cutting panels)to form a paste.

The shelf angle should be installed withconsideration of the length of the stockpanels available. For instance, if using a2700 mm long panel then allow adistance of 2715mm below the eaveslining to the angle. The 15mm gap at thetop will make installation easy and can becovered with a timber moulding.

If the wall is higher than 3000mm to the eaves, a horizontal panel (possibly300mm wide) could be installed on topof the vertical panels. In this case, twoadditional tophats will be required to fixthis extra panel to the wall.

Panels over the windows and in thegables should be installed as alreadydetailed in this manual.

(B) Construction

The installation of the panels is very similar to the processes already detailedin this manual, with consideration given to the following items.