Pitched Roofing

Underlays, membranes and systems for pitched tiled and slated roofs. Everything in this range sits beneath the tile or slate as the roof's secondary barrier — the layer that catches wind-driven rain and anything that gets past the covering, and carries it safely to the gutter.

Breathable or non-breathable?

Most modern UK pitched roofs use a breathable membrane, which lets water vapour escape the roof space and can often be used without additional high-level ventilation. Traditional non-breathable felt needs ventilation at eaves and ridge to stop condensation forming on the underside. Which one you need depends on how the roof is insulated and whether there is a vapour control layer at ceiling level.

Getting the detailing right

Underlay is laid in horizontal courses from the eaves upwards, each course lapping over the one below and supported by the tiling battens. Allow a slight drape between rafters so water runs down the membrane rather than pooling on a batten. At the eaves, make sure the underlay discharges into the gutter and not behind it.

Working on a flat or low-pitch section too? See our EPDM rubber roof kits and roof insulation boards. If you are weighing up doing the work yourself, read EPDM roofing: should you DIY or hire a roofer?