Rooftec Pro Breathable Roofing Membrane 140gsm 1.5m x 50m

Rooftec Pro 140gsm is a polypropylene breathable roofing membrane designed for pitched roof installations where you need reliable waterproofing combined with vapour permeability. At 0.70mm thick and 140gsm, it sits in the mid-weight category that most roofers reach for on standard domestic and commercial projects. BBA certified and conforming to BS 5534:2014 Annex A, this is a membrane you can specify with confidence.

The key balance with any breathable roofing membrane is stopping liquid water getting in while letting water vapour escape from the building below. Rooftec Pro handles both. The water vapour resistance is rated at 0.02m, which means moisture from inside the structure can pass through without accumulating in the roof build-up. Water penetration resistance is classified W1, the highest classification for resistance to water ingress. It is also UV stable for up to three months, which gives you a reasonable window between laying the membrane and completing the tile or slate work above it.

Where Rooftec Pro Breathable Roofing Membrane Gets Used

Rooftec Pro is suitable across a wide range of pitched roof applications. The pitch range of 12.5° to 75° covers the vast majority of domestic roofs, from shallower pitches right up to near-vertical. It works in both supported installations, where the membrane sits over close-boarded sarking, and unsupported installations, where it spans freely between rafters. Scottish sarking board applications are specifically covered, which is useful on cross-border projects where building practice differs.

The membrane performs equally well in warm roof and cold roof configurations, and it is compatible with both timber frame and metal frame construction. That covers a broad range of new build and refurbishment work without needing to specify a different product for each scenario.

Fixing and Sealing the Membrane

Rooftec Pro is installed horizontally across the roof, running over the rafters or insulation. Overlaps at the ridge should be a minimum of 20cm, with an additional 15cm lap along the printed guideline. On pitches below 22°, increase the horizontal overlaps to 20cm or more to account for slower water run-off.

Any seams, butt joints or areas of accidental damage should be masked with a compatible membrane adhesive tape before tiling commences. Where the membrane meets masonry or other substrates at verges, abutments or around penetrations, use silicone or self-adhesive butyl tape to form a continuous seal. The 1.5m width covers three rafter bays in one pass on most standard roof structures, which keeps installation moving at a decent pace.

Available in 1m and 1.5m widths, both on 50m rolls, so you can match the roll width to the rafter spacing and minimise waste on awkward roofs. Reaction to fire classification is E-d2, in line with standard polypropylene underlay products used in the UK market.