Roofers Choice 170 is a multi layer laminate film composite made of polyolefin materials, resulting in a pitched roof underlay that has high vapour permeability but is also highly water resistant.
Roofers Choice 170 is suitable for both Commercial and Domestic buildings, it is the ideal roof underlay for Warm and Cold Pitched Roofs
Roofers Choice 170 membrane has recieved BBA Approval and complies with BS5534: 2014 Code of Practice for slating and tiling for pitched roofs.
Manufactured without the use of CFC’s Roofers Choice 170 is 100% recyclable and is very durable with high tensile and nail tear strength properties. These, coupled with excellent UV and heat stability properties ensure a life-span in excess of 30 years
.
Recommendations for the use of vapour permeable membranes in pitched roofs are contained in BS 5250 : 2011 ‘Code of practice for control of condensation in buildings’.
Roof Space Ventilation
Prevention of Condensation The complete roof construction, ceiling boards, underlay, insulation and roof tiles should be considered as a total roof system with regard to condensation risk, details of which can be found in our BBA certificate. The risk of condensation is greatest during the first heating period when the moisture levels are high. Roof Space Ventilation The NHBC require that for all New Build Homes, ridge or high level ventilation is installed when a vapour permeable membrane such as Roofers Choice 170 is used. We recommend the membrane should stop 5 to 30 mm from the apex of the roof and a ventilated dry ridge system be used to achieve the required level of ventilation. General Roofers Choice 170 must be installed with the black printed side face- up and overlapped with the minimum dimensions listed. Trimming is achieved with a sharp knife. When partially supported with a horizontal lap between battens, an extra batten should be introduced 25 mm above the bottom edge. This will restrain the lap from opening under wind uplift. Weather Tightness VapR-free Plus is highly water resistant and prevents the ingress of wind driven rain. It can be used as a temporary roof covering and left exposed to the elements, however this period should be kept to a minimum.
Technical Data
| Property | Units | Value |
|---|---|---|
| Weight | g/m² | 170 |
| Water Vapour Resistance | Sd (M) | c.0.02 |
| MN/sg | 0.19 | |
| Water Vapour Transmission | g/m²/24hr | 1065 |
| Fire Rating | - | EN13501-1 |
| Exposure Times UV Degradation | - | 3 months |