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Thermakraft CoverTek 401

Covertek 401 is an affordable lightweight roof underlay designed to keep water out and allow moisture to escape. Covertek 401 is a more affordable option where a product does not require a fire-retardant underlay. It is stable, shrink resistant, easy to handle and easy to install.

Key Features
  • Tear resistant and strong
  • Affordable, lightweight synthetic underlay
  • BRANZ appraised
Scope of Use

Designed for use as a roof underlay 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
  • Situated in NZS3604 Wind Zones up to, and including, ‘Extra High’ (Roof only)

Refer BRANZ Appraisal No 943 (2016) for full details.

  • Suitable with masonry tile, metal tile or profiled metal roof cladding
  • Suitable for timber or steel framed buildings — Direct fix or cavity fix
  • Self-supporting in roof pitch application greater than or equal to 10 degrees (Refer to installation guide)
  • Will provide temporary weather protection during construction (maximum 7 days), same day coverage recommended
  • Covertek 401 may be installed during adverse conditions (rain/snow) without affecting durability or performance
  • Suitable for use under dark coloured roofs
Limitations on Use
  • Cannot be used as a wall underlay
  • Must not be exposed to the weather or UV for more than 7 days
Statement of Building Code Compliance

 Covertek 401 Roof Underlay, if used, designed, installed and maintained in accordance with the statements and conditions of the BRANZ Appraisal, will meet, or contribute to meeting the following provisions of the NZBC:

  • Clause B2 DURABILITY: Performance B2.3.1 (a), not less than 50 years, B2.3.1 (b), 15 years and B2.3.2. Covertek 401 Roof Underlay meets these requirements. See Paragraphs 9.1 and 9.2
  • Clause E2 EXTERNAL MOISTURE: Performance E2.3.2. When used as part of the roof cladding system, Covertek 401 Roof Underlay will contribute to meeting this requirement. See Paragraphs 12.1 and 12.2
  • Clause F2 HAZARDOUS BUILDING MATERIALS: Performance F2.3.1. Covertek 401 Roof Underlay meets this requirement and will not present a health hazard to people
BRANZ Appraised
BRANZ Appraised
Data Sheet

Issue 6, Jun 2021

Quick Reference Guide

Issue 4, Aug 2021

BRANZ Appraisal

No.943 [2021] 1 Dec 2021

Thermakraft Warranty Statement

Issue 2, Nov 2019

Thermakraft on Masterspec
Installation and Operation

Issue 1, Nov 2019

Thermakraft Ltd are a leading New Zealand manufacturer of Synthetic and Bituminous underlays for the roof and wall with over 30 years experience

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