A moisture-variable vapour barrier for use in the air-tight layer. The functional membrane changes its diffusion resistance depending on the current humidity. During the winter months room atmosphere is generally dryer. The sd-value of the vapour barrier increases. This process results in the penetration of only a little water vapour into the construction and/or into the insulation. In summer, when there is sufficient solar insulation, the relative humidity behind the membrane is higher as a result of reverse diffusion. The water molecules are stored in the membrane. The sd-value sinks, causing more water vapour to escape from the construction and into the rooms and the building element becomes dryer.
Delivery takes 2-3 working days and is free for orders over £200.00 for most of our products. Orders under this amount have a £10 shipping fee. Please note, some may incur a surcharge due to the dimensions and weight of the product. This will be calculated at the cart stage.
We offer a 30 day return policy for goods that are undamaged and are in their original packaging. Buyer pays the return postage (£30.00 plus Vat) unless the item is faulty or damaged upon receiving the goods then we would kindly ask for photographic evidence so that we can take the matter up with our shippers.