Kerabit Protect

Kerabit Protect is a diffusion-open underlay. This product consists of two layers of polypropylene fabric interlayered by a microporous polypropylene sheet.

Kerabit Protect can be installed directly on the surface of thermal insulation. However, a provision must be made for a ventilation gap between the roofing and the underlay.


Manufacturer / Manufactured for
Nordic Waterproofing Oy, Lohja plant
Country of origin
Conformity marking
Fire Classification

category E

Nominal weight
132 g/m²
Rolls size
1,5 x 50 m / 75 m²
Packages / pallet
36 rlls
Weight / package
9,7 kg
Weight / pallet
375 kg


Kerabit Protect underlay can be used on roof pitches of 1:3 and steeper. Tightness can be ensured by glueing the seams with a mesh-reinforced Kerabit Butyl Strip, laid between the lengths of the underlay, or by glueing Isola Wind Barrier Tape over the seams. The overlaps must be at least 15 cm.

Kerabit Protect is installed longitudinally, starting from the eaves. Before the installation of the first length of the underlay, a supportive board and an eave flashing must be installed on the lower section of the roof plane.

  • Tyvek Windbarrier tape for seaming, repairing and waterproofing the underlay
  • Isola FlexWrap for fastening the underlay to a chimney and for lead-throughs.
  • Kerabit Butyl Strip for fastening the underlay to the eaves flashings and the laths and the underlay