Underlay membranes

Tuoteryhmäkuva-aluskatteet

An underlay is an essential part of the roof construction

Special attention should be paid to the selection of the underlay, particularly with discontinuous roofing (tile, tin etc.) which are not waterproof. There are many types of underlay available and it is not immaterial which one you choose. The lightest solution to lay under a tin or tile roof is a plastic hanging underlay, whereas the sturdiest and most compact alternative is a solid wood decking and an underlaymembrane laid on top. 

Feature Kerabit
RA-TA
60 K+
Kerabit
Protect
Kerabit
Super
Kerabit
700 UB
Kerabit
2200 UB
Kerabit
2500 UB
Kerabit
2600 UB
Fleece
Kerabit
3000 UB
Underlay classification AKV 1 - AKV 1 AKV 1,
AKK 1
AKK 2 TL 3,
AKK 1
TL 2,
AKK 1
TL 2,
AKK 1
Basis weight, g 130 130 210 700 2200 2500 2600 3000
Bitumen underlay       x x x x x
Plastic underlay x x x          
Carrier layer
material
Poly-
ethene
Poly-
propylene
Poly-
propylene
Poly-
ester
Fibre-
glass
Reinforced
polyester
Reinforced
polyester
Reinforced
polyester
Diffusion-open   x x          
Adhesive edge     x x x x x x
Hanging installation x x x x        
Fixed installation       x x x x x
Step resistant
as hanging
    x x        
Under bitumen roofing       x x x x x
Under tile roofing x x x x x x x x
Under tin roofing x x x x x x x x
Sand on surface         x x   x
Roofing to be installed within
one
month
within
one
month
within
one
month
within
one
month
within
one
month
When
necessary
after
winter
within
one
month
When
necessary
after
winter
 
* If you install an underlay membrane late in the autumn, we recommend that you choose Kerabit 2500 UB or 3000 UB, whereby the end result is better and more durable. In such a case, you can install the surface roofing of a high-pitched roof in the spring when the weather is warmer.