Maxi Plus Roof Underlay

Maxi Plus Roof Underlay is a medium-duty, tri-laminate underlay comprising outer non-woven layers and a central functional membrane. It is coloured blue on the front and white on the back and is supplied in rolls of 45㎡, 1.45 m wide x 31.03 m long.

Maxi plus roof underlay is categorised in accordance with AS/NZS 4200.1 as follows: 

• Duty classification: Medium duty 

• Emittance classification: Non-reflective 

• Conductivity: Electrically non-conductive 

• Water control classification: Water barrier 

• Vapour control classification: Vapour permeability – Class 4 vapour permeable 

• Flammability classification: Low flammability.

Maxi Plus Roof Underlay may be used with all building classes (1-10) and where the primary structure is timber or steel framing in Class 1 and Class 10 buildings and steel framing only in Class 2, 3, 4, 5, 6, 7, 8, and 9 buildings. 

Maxi Plus Roof Underlay may be used in conjunction with masonry tile, pressed metal tile or profiled metal roof cladding.

Conditions of Use

• Maxi Plus Roof Underlay is suitable for non-cyclonic wind zones (AS 4055) up to and including N3. 

• Maxi Plus Roof Underlay has a flammability index of 1 and, therefore, an AS/NZS 4200.1 flammability index of low. However, in bushfire-prone areas, the designer and installer must establish compliance with AS 3959. 

• Maxi Plus Roof Underlay may be exposed to UV and weather for up to 60 days before being covered with a roofing system. Refer to the Masons Maxi plus roof underlay technical data statement.

If designed, installed and maintained in accordance with all Masons requirements, Maxi plus roof underlay will comply with or contribute to compliance with the following performance claims: 

NCC (2020) Provisions & state or territory variations 

Compliance with any manufacturer’s installation instructions, maintenance, OH & S statements, MSDS and other Health and Safety declarations will provide the necessary Health and Safety Information pertaining to the product.