Description

Thermakraft Covertek 401 Roof and Wall Underlay is a non-fire-retardant, synthetic building underlay for use under roof and wall claddings. 

Scope

Roof Underlay

Thermakraft Covertek 401 has been appraised for use as a self-supporting roof underlay on lined buildings within the following scope:

• the scope limitations of NZBC Acceptable Solution E2/AS1, Paragraph 1.1 for timber-framed buildings; or,
• the scope limitations of NASH Building Envelope Solutions, Paragraph 1.1 for steel-framed buildings; and,
• with masonry tile roof cladding; and,
• with metal tile roof cladding; and,
• with profiled metal roof cladding; and,
• situated in NZS 3604 and NASH Standard Part 2 Wind Zones up to, and including, Extra High.

Wall Underlay

Thermakraft Covertek 401 has also been appraised for use as a flexible wall underlay for lined buildings within the following scope:

• the scope limitations of NZBC Acceptable Solution E2/AS1, Paragraph 1.1 for timber-framed buildings; or,
• the scope limitations of NASH Building Envelope Solutions, Paragraph 1.1 for steel-framed buildings; and,
• with direct-fixed absorbent and non-absorbent wall claddings; or,
• with absorbent and non-absorbent wall claddings installed over an 18 mm minimum drained cavity; or,
• with masonry veneer in accordance with NZBC Acceptable Solution E2/AS1 for timber-framed buildings or to NASH Building Envelope Solutions for steel-framed buildings; and,
• situated in NZS 3604 and NASH Standard Part 2 Wind Zones up to, and including, Very High; or,
• situated in 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 or NASH Building Envelope Solutions Paragraph 9.1.7.2.

Specific Design

Thermakraft Covertek 401 Roof and Wall Underlay has also been appraised for use on lined buildings subject to specific weathertightness design. Building designers are responsible for the building design and for the incorporation of Thermakraft Covertek 401 Roof and Wall Underlay into their design in accordance with the declared properties and the instructions of Kingspan Insulation NZ Limited.