Why the membrane is vapour-permeable

The central, invisible part of the membrane – the functional film – is responsible for its vapour permeability. If you looked at it under a microscope, you would see microchannels – small enough to keep liquid water out, but large enough for water vapour molecules to pass through.

Water vapour molecules are many times smaller than a drop of water. If a vapour molecule was the size of a tennis ball, the diameter of the channel would be about 280 m. But for a drop of water, this is still too tight to squeeze through. Now imagine how many tennis balls, which are our vapour molecules, could fit into such a channel at the same time. For water vapour, unlike for water droplets, the microchannel is gigantic and lets it pass freely. No drop of water will squeeze through it. This is our secret – a dry and safe roof with Corotop® membrane. But we do not keep secrets from you.

How long will the membrane last without tiling