Description

The Hermpac Bevelback and Rebated Bevelback Weatherboard Cavity System is a cavity-based timber weatherboard external wall cladding system for residential and light commercial type buildings where domestic construction techniques are used. 

The system consists of horizontally fixed Hermpac bevelback and rebated bevelback weatherboards, cavity battens, flashings and accessories and is finished with a premium penetrating oil, stain or an exterior paint system to Hermpac specifications. 

The system incorporates a primary and secondary means of weather resistance (first and second line of defence) against water penetration by separating the cladding from the external wall frame with a minimum 18 mm drained cavity.

Scope

The Hermpac Bevelback and Rebated Bevelback Weatherboard Cavity System incorporating stain finished weatherboards and paint finished DuraLarch and Ashin-Dura weatherboards has been appraised as an external wall cladding system for buildings within the following scope:

• the scope limitations of NZBC Acceptable System E2/AS1, Paragraph 1.1; and,
• constructed with timber framing complying with the NZBC; and,
• with a risk score of 0-20, calculated in accordance with NZBC Acceptable Solution E2/AS1, Table 2; and,
• situated in NZS 3604 Wind Zones up to, and including Extra High.

The Hermpac Bevelback and Rebated Bevelback Weatherboard Cavity System incorporating stain finished weatherboards has also been appraised for weathertightness and structural wind loading when used as an external wall cladding system for buildings within the following scope:

• the scope limitations of NZBC Acceptable Solution E2/AS1, Paragraph 1.1 with regards to building height and floor plan area; and,
• constructed with timber framing subject to specific engineering design; and,
• situated in specific design wind pressures up to a maximum design differential ultimate limit state (ULS) of 2.5 kPa.

The Hermpac Bevelback and Rebated Bevelback Weatherboard Cavity System incorporating paint finished cedar weatherboards has been appraised as an external wall cladding system for buildings within the following scope:

• the scope limitations of NZBC Acceptable System E2/AS1, Paragraph 1.1; and,
• constructed with timber framing complying with the NZBC; and,
• with a risk score of 0-20, calculated in accordance with NZBC Acceptable Solution E2/AS1, Table 2; and,
• situated in NZS 3604 Wind Zones up to, and including Medium when studs are at maximum 600 mm centres, and NZS 3604 Wind Zones up to, and including Very High when studs are at maximum 400 mm centres.

The Hermpac Bevelback and Rebated Bevelback Weatherboard Cavity System must only be installed horizontally on vertical, flat surfaces.

The Hermpac Bevelback and Rebated Bevelback Weatherboard Cavity System is appraised for use with aluminium window and door joinery that is installed with vertical jambs and horizontal heads and sills. (The Appraisal of the Hermpac Bevelback and Rebated Bevelback Weatherboard Cavity System relies on the joinery meeting the requirements of NZS 4211 for the relevant Wind Zone or wind pressure.)