3 Layers Laminated Breathable Membrane Pitched Roof Underlay

3 layers laminated Breathable Membrane pitched roof underlay

High-quality polyethylene breathable membrane is being used more and more. Building regulations have encouraged the development of more energy efficient building construction techniques. Therefore buildings are becoming more air tight via improved draught proofing, double glazing and the use of central heating. The result is an increase in the water vapour content within the building and this combined with better insulated buildings can create a colder loft space and the risk of condensation forming. Condensation, be it surface or interstitial, can damage the roof construction. 

People and their normal activities within the building can produce 5-15 litres of water vapour per day. Of this up to 60% can diffuse through gaps in the ceiling, light fittings and loft hatches and enter the roof space. To counteract this, it has been  recommended to ventilate the loft space to allow water vapour to disperse before it is possible to condense and cause damage.