FNS vapour open membrane
FNS: 3-layer: 125 g/m2 (70 g spunbonded polypropylene, 25 g film, 30 g spunbonded polypropylene)
3-layer laminate, comprising of 2 spunbonded layers and a UV stabilised film, which is breathable whilst maintaining good water repelling properties.
Use:
On the cold side of the (sloping) roof = on the outside of the building,
just below the roof tiles. Often in combination with a damp inhibitor.
Function:
ensures that the
condensation in the construction is able to get out quickly (damp-open)
ensures that powder
snow or water that ends up under the roof tiles does not get into the
construction (damp proofing)
Damp-open / damp proofing
the level of damp-openness
is expressed in the Vapour Transmission Rate: g/m2/24hours.
the level of damp
proofing is expressed in ‘water column’ in metres.
