Ventilation membranes
Main purpose of the vapour diffusion roofing membranes is to waterproof the roof but they also possess ventilation function allowing water excess to escape from under the membrane. Specialist vapour diffusion torch-on membrane Wentylacyjny Werner PYE PV250 S54 is used to make  new roofs as well as renovate old ones.

Membrane’s underside contains specially formed maze of channels which allow excess vapour move from the roof to the breather vent and prevent blistering.

Using single layer vapour diffusion membrane Wentylacyjny Werner PYE250 S54 allows effectively ventilate surface of the roof without the need to use additional layer of perforated underlay.