Roof Membrane Under Tiles

The main purpose of roofing underlay is to reduce the effect of wind loading on the slate or tile roof covering according to bs5534 the code of practice for slating and tiling.

Roof membrane under tiles.

Roof pitch is another important consideration since it will determine how big the membrane lap needs to be. Resistant to wind driven rain and snow these membranes must perform to a satisfactory level which includes criteria on wind uplift. Roof breather membrane on the other hand allows far greater moisture transfer making it crucial that there is adequate air movement above. Prevent tiles from being dislodged by assisting with the containment of upward pressure forces in a roof that can build up during storms.

As a general guide pitches under 14 degrees should have a lap of 150mm while those over 15 degrees usually require a lap of 100mm. Used for the prevention of draughts and dust penetration into the roof spaces through tiles and prevents damage to the ceilings rotting of timbers and corrosion of plumbing. When non breathable membrane is used below the slates or tiles very little moisture makes its way into the batten space above. According to bs 5534 the british standard for slating and tiling and bs 5250 the code of practice for the control of condensation there are two main types of roofing underlays.

The main purpose of under tile plastic membrane is to. Prevent leaks with roof membrane and tile underlayment. Tile roof underlayment is a membrane applied directly to the tile roof deck. The secondary purpose of sarking felt is to provide a waterproof barrier and allow for the safe disposal of water that has collected on the upper surface of the.

Prevent the ingress of wind driven rain and dust in roofs that are not 100 waterproof. Free delivery over 25. The material equalises the pressure and compliments the function of the roof tiles. Flexible and easily handled.

High resistance non breathable underlays and low resistance breathable or vapour permeable membranes. If your roof pitch is over 35 degrees you may be able to reduce the lap to 75mm. Let s look at these in more detail. Wind uplift was introduced as part of regulations in 2015 as with a lot of wind uplift under a membrane the material can force roof tiles off the roof and endanger pedestrians below.

Underlayment is indispensable in the construction of tile roofing for the following reasons.