Kerabit OSB Roof Board

The Kerabit OSB roof board is a durable building board made from cross-glued strands of wood. As no formaldehyde is used in its production, this product is environmentally friendly. The size of the boards is 2.7 x 1.2 m.

During the manufacturing process the glue forms a surface that prevents dirt and moisture from permeating the boards.

The 18 mm thick boards are suitable for k600 and k900 truss spacings. The boards are fixed onto the trusses with at least 50 mm nails or screws with approximately 15 cm spacing.

The 15 mm thick OSB roof boards are suitable for k600 truss spacing.

Both boards are tongued and grooved all around.


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

D, s2, d0

Nominal thickness
18 mm / 15 mm
Packages / pallet
36 / 44 boards on a pallet
Weight / package
36,9 kg / 30,7 kg
Weight / pallet
1478,4 kg

Fastening of Kerabit OSB roof boards

For fastening Kerabit OSB roof boards, we recommend:

Alternative 1: Partially threaded screw

  • there is a smooth area between the screw head and thread
  • weatherproof 
  • length minimum 55 mm, drills down into the substrate at least 2/3
  • gauge minimum 4.2 mm
  • fastening with 15 cm spacing

Alternative 2: Hot-galvanised nail

  • Length minimum 60 mm
  • fastening with 15 cm spacing

Expansion gaps

With all square adged panels an expansion gap of at least 3 mm should be allowd between the individual panels. Panels with a tongue and groove prolife hav an expansion gap included in the tongue and groove joint. In long runs more than 12 meters and additional expansion gap of approximately 25 mm should be allowed every 12 metre in either direction of the area.

  • fastened with minimum 50 mm ring shank nails or threaded nails or self-drilling screws