BEVELBACK WEATHERBOARD CAVITY SYSTEM
which provide a minimum ventilation opening area of 1000 mm2 per lineal metre of wall.
The Hermpac Bevelback and Rebated Bevelback Weatherboard Cavity System must be installed over building paper or wrap complying with NZBC Acceptable Solution E2/AS1, Table 23, or other BRANZ Appraised breather-type membranes.
Unlined gables and walls must incorporate a rigid sheathing or an air barrier fixed to the framing, which meets the requirements of NZBC Acceptable Solution E2/AS1, Table 23. Where rigid sheathings are used, the fixing length must be increased by a minimum of the thickness of the sheathing.
Inter-storey drained joints must be provided for walls over two storeys in height in accordance with the requirements of NZBC Acceptable Solution E2/AS1, Paragraph
Hermpac Bevelback and Rebated Bevelback Weatherboards
Hermpac Bevelback weatherboards must be overlapped a minimum of 32 mm. Hermpac Rebated Bevelback weatherboards must be overlapped a minimum of 25 mm with an expansion gap of 2 mm at the overlap between boards. Hermpac Bevelback and Rebated Bevelback profiles are all manufactured in accordance with BRANZ Bulletin 411 (Refer to E2/AS1 page 106, paragraph 220.127.116.11).
The weatherboards shall be pre-coated with the selected coating (prior to site delivery and installation) by Herman Pacific Limited associate Machinecoat (NZ) Ltd, by the flood coat inundation method or in-line spray coat system (subject to coating type selected).
Pre-finished Bevelback and Rebated Bevelback weatherboards shall be over-coated and maintained in accordance with the coating manufacturer’s specification. All cut ends and/or uncoated surfaces shall be coated during installation to protect against the penetration of moisture, post installation.
The weatherboards shall be fixed through the cavity battens to the studs at maximum 600mm centres using Hermpac weatherboard fixings (refer to Section 1.5 of this specification).
External corners shall be weatherproofed by the use of corrosion resistant corner flashings and Western Red Cedar corner battens HP 201 or HP 202 with Hermpac scribers, or Hermpac corner soakers.
Published: September 2009