Description

Thermakraft Covertek 403 Roof and Wall Underlay is a synthetic, fire retardant, absorbent, breathable building underlay for use under roof and wall claddings.

The product consists of a micro-porous water resistant film ultrasonically bonded between two layers of non woven spun-bonded polyolefin.

Thermakraft Covertek 403 Roof and Wall Underlay is coloured white on the top and bottom faces with green Covertek 403 branding on the exposed face.

Scope

Thermakraft Covertek 403 Roof and Wall Underlay use is certified

a). as non self supporting roof underlay on buildings:

• i. within the scope limitations of NZBC Acceptable Solution E2/AS1, Third Edition including amendment 10 (5 November 2020), Paragraph 1.1 with regards to building height and floor plan area; and,
• ii. with
  
  • masonry tile roof cladding; or,
  • with metal tile roof cladding or
  • profiled metal roof cladding; and,
• iii. situated in NZS 3604-2011 and NASH Standard Part 2 Wind Zones up to, and including Extra High.
• iv. with a roof pitch of 10° and above

b). as flexible wall underlay for buildings:

• i. within the scope limitations of
  
  • NZBC Acceptable Solution E2/AS1, Third Edition including amendment 10 (5 November 2020), Paragraph 1.1 for timber-framed buildings; or,
  • NASH Building Envelope Solutions, Paragraph 1.1 for steel-framed buildings; and,
• ii. with absorbent or non-absorbent wall claddings either direct fixed or installed over an 18 mm minimum drained cavity; or,
• iii. with masonry veneer in accordance with
  
  • NZBC Acceptable Solution E2/AS1 Third Edition including amendment 10 (5 November 2020) for timber-framed buildings or
  • NASH Building Envelope Solutions for steel-framed buildings; and,
• iv. situated in
  
  • NZS 3604 and NASH Standard Part 2 Wind Zones up to, and including, Very High; or,
  • NZS 3604 and NASH Standard Part 2 Wind Zones up to, and including, Extra High when used over a rigid wall underlay in accordance with NZBC Acceptable Solution E2/AS1 Third Edition including amendment 10 (5 November 2020) or NASH Building Envelope Solutions Paragraph 9.1.7.2.