TRW Fibreclad Installation Manual

Introduction

The TRW Fibreclad System™ is made up of 75mm M Grade polystyrene (EPS) sheets that are fixed to timber or steel framing over the surface of a 25mm cavity. The EPS is then reinforced and over coated with a range of specially blended light weight renders and painted with a 100% acrylic paint system.

It must be clearly understood that the primary purpose of any external cladding is to weather proof the structure. TRW Fibreclad System™ provides a primary and secondary means of weather defence against water penetration by separating the cladding from the external wall framing with a nominal 25mm drained cavity.

All Polystyrene Insulation Board, starter foam, window sills, window reveals, window heads, polystyrene battens, fibreglass mesh, fixings and render products used for the TRW Fibreclad System™ must be supplied by TRW or one of its certified distributors.

This manual has been set out as near as possible to the actual construction sequence and it must be read in conjunction with the Technical Specifications.

Framing Set Out(Timber or Steel)

Timber framing must comply with AS 1648 National Timber Framing Code. There are four Wind Zone categories: Low, Medium, High and Very High. The Building Wind Zone for the job must be clearly understood before the installation of TRW Fibreclad System™ and the frame must be constructed and braced accordingly. In all cases studs must be set out at 450mm maximum centres. Noggins must be flush fitted at maximum 800mm centres. All eve junctions, openings, wall/roof junctions and foundation details must have support for the sheet edges. Timber framing must have a maximum moisture content of 24% at the time cladding commences. For steel framing the minimum framing specification is ‘C’ section studs and noggins of overall section size 75mm web and 32mm flange. Steel thickness must be a minimum of 0.55mm. TRW Fibreclad System™ requires a straight and true frame to be fixed to. We accept no responsibility for variations in horizontal or vertical straightness of walls due to the frame not being straight.

Building Wrap

A building wrap complying with AS/NZS4200.1 must be used in all circumstances. Building wrap must be installed horizontally and be continuous around corners. The wrap must be lapped 75mm minimum at horizontal joints and 150mm minimum over studs at vertical joints.

Flashings

Flashing tapes complying with Australian standards must be used around all penetrations. All penetrations must have internal air seals applied.

Joists designed to carry decks need to have a continuous flashing fitted before the polystyrene is fixed. Check if there are any special back flashings required where the TRW Fibreclad System™ joins another substrate or curtain wall construction.

Roofing

Where areas over roofs are to be fitted with TRW Fibreclad System™, the roof/wall flashing must be installed prior to the commencement of cladding.

Pipes & Meter Boxes

It is critical that pipes are flashed appropriately in accordance with AS/NZS 2904. All pipes must have the building wrap turned to the outside of the building and have the building paper taped to the outside of the pipe. All pipes must have a downward rake of a minimum of 5 degrees and must be sealed in place using Sikaflex or another approved equivalent both before the installation of the TRW Fibreclad System™ and after completion. All meter boxes must be correctly flashed in accordance with the detailed drawings for the TRW Fibreclad System™. Particular attention to detail and workmanship must be given to the weatherproofing details relating to flashing and sealing building penetrations or junctions with other building materials. All junctions between the TRW Fibreclad System™ substrate and dissimilar technical literature materials must be correctly flashed and sealed with Sikaflex or another approved equivalent. The sealant must be installed in strict accordance with the manufacturer’s requirements and must be left to properly cure prior to rendering.

Eves,Gable Ends & Unlined Walls

Eves shall be fixed into place before the cladding is installed and allowance made to close off the cavity with framing or battens to stop airflow into the roof space. After the TRW Fibreclad System™ has been completed a 5mm bead of Sikaflex or another approved equivalent should be installed at the eve/polystyrene intersection. Reverse raking eves or eves less than 450mm wide must be flashed. To ensure the EPS substrate is not affected by timber shrinkage in areas that are not traditionally lined (e.g. gable ends), it is highly recommended that the internal walls of these areas are adequately braced with a thin sheet of plywood or an alternative bracing material. Alternatively, the timber in these areas must have a moisture content of no greater than 18% and must remain that way throughout the entire construction process.

Builders Check List for Fitment of TRW Fibreclad System

TRW Fibreclad System requires all of the following to be completed PRIOR to the installation of the TRW Fibreclad System™.

• Builder to provide details of expansion joint locations (max 5 metres apart)
• Builder to install all corner and window studs to fix foam too prior to commencement. Windows require additional studs inside window studs above and below windows to fix sills, reveals and heads too
• Builder to fix off all windows prior to commencement
• Builder to fit eve sheets prior to commencement
• Builder to install all flashings required prior to commencement
• Builder to install building wrap prior to commencement
• Builder to provide safe and certified scaffold for work platforms and fall protection to all work areas required
• Builder to provide safe and certified access and egress to required work areas
• Builder to provide roof protection for all works undertaken on roof tops i.e. sheet flooring over metal roofing
• Builder to supply bin for disposal of all rubbish and waste materials
• Builder to provide clean and working toilets for workers
• Builder to caulk all window reveals, penetrations and expansion joint at completion of works
• Builder to sign and return contract and check list prior to commencement

Project Address:
Name of Authorised Signatory:
Signature:
Date:

 

Installation Steps

Flashing Tape

Building wrap must be taped to all penetration with an approved TRW flashing tape before any battens are fitted. Penetrations should be taped from the bottom up ensuring that any moisture can run freely over joints with no restriction. All joints should overlap a minimum 50mm.

Battens

TRW Fibreclad System™ battens for use under an EPS substrate are manufactured from high density (Class H) expanded polystyrene with an approximate density of 24kg/m3 and measuring 25mm x 45m. All battens must be nail to the framing or alternatively glued to the chosen building wrap. Additional vertical battens are required at internal and external corners and above and below openings. Were battens are used above openings ensure a minimum 5mm gap is left between the bottom of the batten and the head of the opening for water to be able to freely drain away. A 5mm gap between the sides of openings and battens is also required for water to be able to freely drain away. At the eve and external corners the airflow must be blocked off and gables must be lined or incorporate an air barrier. The fewer horizontal battens that are used the better. If any horizontal battens are required always leave a minimum 5mm gap to the vertical batten for water to drain away freely. In first storey applications batten must be stopped at the top edge of the roof flashing. If the batten runs over the roof flashing this will cause the starter foam to kick out.

Fixings

Polystyrene sheets are fixed through the cavity battens and spacers to the studs with 130 x 4mm hot-dipped galvanised screws topped with a 42mm washer. Screws are too be placed 50mm in from all joints and then 400mm centres (10 per sq/m). All external corners must have screws placed at spaces no more than 200mm centres.

TRW Starter Foam

TRW Starter Foam has been designed to eliminate the use of cavity closers. TRW Starter Foam will leave a 2mm-3mm gap between the flashing and the back of the Starter Foam. (Minimum 1000 sq/mm air gap per lineal metre). This will allow any water to escape and air flow to dry any condensation that may occur on the back of the foam. The bottom edge of TRW Starter Foam is pre coated to prevent UV rays and the elements degrading the foam. The bottom edge is also cut with an upward 25 degree rake to act as a drip edge and minimise the gap between the foam and the flashing on pitched roofs. TRW Starter Foam should be fitted after battens and before any other foam is fitted. On first storey applications a 15mm-20mm gap between the bottom edge of the starter foam and the roof is desirable. On each corner stud measure up the desired distance for the top edge of the starter foam to leave a 15mm – 20mm gap at the bottom edge, then flick a chalk line across the battens. This will ensure the bottom edge is straight. TRW Starter Foam must be mitre cut and glued at all internal and external corners. For ground floor applications TRW Starter Foam must be left 75mm above ground level.

TRW Sills & Reveals

TRW Sills are cut on a 25 degree fall to ensure water runs away from windows. The top edge of the sill and the internal edges of the reveals are pre coated eliminating the need for external angle beads around windows. 5mm gaps should be left between all joints. Window components should be fitted after battens and starter foam.

Foam Sheets

After flashing tape, battens, sills and reveals are fitted infill the rest of the wall with sheets. Sheets should be hung horizontal were possible and joints staggered. Leave 5mm gaps between all joints.

Back Blocking

Back Blocking is only required were sheets do not meet flush. For back blocking use strips of timber horizontally as ribbons. Timber should not be any thicker than 12mm ensuring that the cavity is not blocked and water can still drain.

Foam Glue

After the foam is fitted all joints must be glued with TRW approved foam glue. Allow glue to dry and then rasp excess glue plush with the face of the foam. It is important to leave 5mm gaps between joints to enable the foam glue to expand in the joint creating a strong bond.