CertClad | Bevelback Cavity System | Radiata Pine | Installation Manual
© ITI Timspec Ltd | BC-RP-IM-V5 | CertClad is a registered Trademark of ITI Timspec Ltd
Last Updated March 2021
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INSTALLING CAVITY BATTENS
7.1 CAVITY CONSTRUCTION
7.1.1 COMPLIANCE
Cavities must comply with NZBC Clause E2/AS1 paragraphs 9.1.8 to 9.1.9.4.
7.1.2 PRECAUTIONS
As solvents in LOSP treatments can affect bitumen based building papers, it is necessary to fillet stack
LOSP treated timber for 7 days after treatment to ensure that solvent has evaporated before contact with
any bitumen-based building paper.
7.1.3 FIXING (NON-STRUCTURAL) CAVITY BATTENS
Cavity battens are to be fixed over underlay to the studs with extra vertical battens to corners to support
flashing when required.
NOTE
Fixing is only temporary for cavity battens as the weatherboard fasteners are used to
permanently fix the batten.
7.1.4 TOP OF WALL DETAIL
No ventilation shall be provided at the top of the cavity. Use a horizontal D4S profile (not a Cavibat batten)
at the top of the wall to close off the top of the cavity. This prevents damp air circulating from the cavity
space into interior spaces such as roof framing or eaves and is extremely
important
where the cavity
finishes beneath an area that is open to a roof space (such as a wall finishing under a soffit).
7.1.5 BOTTOM OF WALL DETAIL
Use a ‘Cavity Base Closure Flashing’ at the bottom of the wall to allow drainage and ventilation but prevent
the entry of vermin. This also applies where cavities end over a window, door or another opening. Ensure
building underlay laps over rear upstand of
the cavity base closure or use flashing tape to seal the top of
the cavity base closure to the building underlay. An angle packer (or part board) may be required to support
bottom of lower weatherboard.
