Kerabit 700 UB is a bituminous underlay, that can be used laid on solid wood underlays or as a hanging, step-resistant underlay.

Both sides of the underlay are covered with a polypropylene fabric. This underlay has an adhesive edge. The surface has no sand.

Kerabit 700 UB can be used as an underlay for tin and tile roofings as well as bitumen shingles.

This product is diffusion-proof, therefore requiring ventilation in the space below the underlay.



  • Kerabit Sealing Adhesive for seaming gable seams
Manufacturer / Manufactured for Kerabit Oy, Lohja plant
Country of origin Sweden
Conformity marking CE
Nominal weight 700 g/m²
Supportive layer polyester
Surface type

polypropylene weave

Rolls size 1,0 x 30 m / 30 m²
Surface bitumen SBS modified bitumen
Colours black
Packages / pallet 24 pcs
Weight / package 21 kg
Weight / pallet 529 kg

Installation to be made on a solid underlay

Kerabit 700 UB is laid over tongue-and-groove boards or building boards suitable for the purpose, parallel to the ridge. Installation is carried out by nailing the underlay in place along the adhesive edge using concealed nailing.

Indicative suitability for different water roof materials:

  • bitumen shingles, inclination 1:5 or steeper
  • machine-seamed tin roofing, inclination 1:10 or steeper
  • tile roofing, inclination 1:5 or steeper.

Check the inclination and materials in the construction plan.


Installation in hanging solutions

The underlay is always laid perpendicular to roof trusses. In hanging solutions, the inclination must be at least 1:4 (14˚). The distance between the roof trusses must be no longer than 1200 mm. The underlay is laid in such a way that it hangs down 10 to 20 mm between the roof trusses.


Handling and storage information

Modified bitumen membranes are stored on pallets in a dry and cool place in an upright position. The rolls must be protected with plastic hoods or tarps. In temperatures in excess of +40 °C, the rolls must be stored away from sunlight.