Description

James Hardie Rigid Air Barriers are a range of rigid wall underlay materials including RAB^TM Board and HomeRAB^TM Pre-Cladding. They are sealed fibre cement sheets designed for use as rigid wall underlay behind wall cladding systems. HomeRAB^TM Pre-Cladding and RAB^TM Board are manufactured using a medium density fibre cement formulation.

Scope

HomeRAB^TM Pre-Cladding

HomeRAB^TM Pre-Cladding has been appraised for use as a rigid wall underlay and temporary weather-protecting sheathing on timber framed buildings within the following scope:

• the scope limitations of NZBC Acceptable Solution E2/AS1; and,
• situated in NZS 3604 Wind Zones up to, and including, Very High; and,
• with the following claddings:
  • absorbent wall claddings directly fixed to framing; and,
  • non-absorbent wall claddings directly fixed to framing with a flexible wall underlay over the HomeRAB™ Pre-Cladding; and,
  • absorbent and non-absorbent wall claddings installed over a nominal 20 mm drained cavity; and,
  • masonry veneer in accordance with NZBC Acceptable Solution E2/AS1.

RAB^TM Board

RAB^TM Board has been appraised for use as a rigid wall underlay and temporary weather-protecting sheathing on timber framed buildings within the following scope:

• the scope limitations of NZBC Acceptable Solution E2/AS1 with regard to building height and floor plan area; and,
• constructed with timber framing, or timber frame infill complying with the NZBC; and,
• with absorbent wall claddings directly fixed to framing; and,
• with non-absorbent wall claddings directly fixed to framing with a flexible wall underlay over the RAB™ Board; and,
• with absorbent and non-absorbent wall claddings installed over an nominal 20 mm drained cavity; and,
• with masonry veneer in accordance with NZBC Acceptable Solution E2/AS1; and,
• when used in conjunction with wall cladding systems suitable for use with maximum wind pressures for structural and weathertightness design of 2.1 kPa serviceability limit state (SLS) and 3.2 kPa ultimate limit state (ULS) where studs are at maximum 600 mm centres, and 3 kPa SLS and 4.5 kPa ULS where studs are at maximum 400 mm centres. 

RAB^TM Board has also been appraised for use as a rigid wall underlay and temporary weather-protecting sheathing on timber framed buildings within the following scope:

• Buildings with a building height not exceeding 25 m; and,
• constructed with timber framing complying with the NZBC; and,
• with inter-storey deflections designed for up to height/180 of horizontal in-plane movement during seismic SLS events (based on a 3 m inter-storey height); and,
• with absorbent and non-absorbent wall claddings installed over a nominal 20 mm drained cavity; and,
• when used in conjunction with either James Hardie or other cladding systems suitable for use with maximum wind pressures for structural and weathertightness design of 2.1 kPa Serviceability Limit State (SLS) and 3.2 kPa Ultimate Limit State (ULS) where studs are at maximum 600 mm centres, and 3 kPa SLS and 4.5 kPa ULS where studs are at maximum 400 mm centres. 

Note: James Hardie Rigid Air Barriers can be used to provide structural bracing. RAB™ Board can also be used in fire resistance rated construction. These aspects have not been assessed by this Appraisal and are outside its scope.