Masons VHP Value Roof Underlay

VHP Value is a high performance, self-supporting, highly breathable, tough, synthetic roof underlay. A huge upgrade from Bituminous Paper.

3 pliable layers: a very high vapour permeable water-resistant membrane and two tough layers of non-woven polyolefin fabric. These layers assist in the control of condensation and water vapour. VHP Value Roof Underlay is not fire retardant.

It has the following benefits:

• Premium performance
• Assists in moisture control - deflects water and air both during construction and as part of the finished roof
• Affordable
• Self-supporting
• Highly breathable - transforms water vapour at higher rates than bitumen impregnated paper
• Temporary weather protection - UV resistance for 21 days - although same-day coverage is strongly recommended
• Codemark Certified

Intended Use

Masons Roof Underlays are for use as a self-supporting roofing underlay.

Building Code Provisions

• B2 Durability: B2.3.1(a), B2.3.2
• C3 Fire affecting areas beyond the fire source: C3.4(c)
• E2 External moisture: E2.3.1 (contributes to), E2.3.2 (contributes to) ; E2.3.5 (ontributes to), (E2.3.6 (contributes to) E2.3.7
• F2 Hazardous building materials: F2.3.1

Conditions and Limitations of Use

1. Masons Roof Underlays are certified for use as a roof underlay and air barrier:

a) on buildings situated in wind zones up to and including Extra High (as set out in NZS3604) with a minimum roof pitch of 3°,

b) under masonry or metal tile and profiled metal roof claddings,

c) in all locations including where it is exposed to view.

2. Masons Roof Underlay shall be:

a) installed in accordance with the manufacturer's installation manual, and

b) installed run vertically or horizontally with or without support for roof pitches greater than 10°, run horizontally with or without support or run vertically with support for roof pitches less than 10°, provided that support is provided where the span is greater than 1200mm, and

c) protected from direct sunlight within 21 days of installation.