Kerabit 1800 UB Fleece

Kerabit 1800 UB Fleece K-MS 150/1800 is a modified bitumen underlay membrane and an underlay membrane for discontinuous roofings.

The product is used as an underlay membrane for machine-seamed and other steel and tile roofings, for example.

The carrier consists of strong polyester. The top surface of the product is coated with a polypropylene fibre cloth and sand granules at the bottom surface. The 100 mm wide  adhesive sections are located on the top and bottom surfaces, on opposing sides.


As far as using of torch-on membrane is allowed, Kerabit 3700 UT Fleece is well suited for details of standing seam metal roof (e.g. upstands, valleys and chimneys), where Kerabit 2600 UB Fleece with self-adhesive edge is used as underlay.

Manufacturer / Manufactured for Kerabit Oy, Lohja plant
Country of origin Finland
Conformity marking CE mark
Reaction to fire Manufacturer’s fire testing certificate
Fire Classification


Manufacturer’s declaration of conformity Kerabit modified bitumen roofing materials
Quality control Quality control agreement between the Plant and Eurofins Expert Services Oy
Nominal thickness 1,7 mm
Nominal weight 1800 g/m²
Weight of the supportive layer 150 g/m² (+/- 10 g/m²)
Supportive layer polyester
Surface type

PP fibre cloth on both top and bottom surface

Rolls size 1 x 15 m / 15 m²
Packages / pallet 24 rolls
Weight / package 27 kg
Weight / pallet 673 kg


The product is used as an underlay membrane for discontinuous roofings on, for example, machine-seamed and other steel and tile roofings. The top surface with no sand does not scratch the zinc coating of the steel roofing.

Handling and storage 

Modified bitumen membranes are to be stored on pallets in a dry and cool place. Use a plastic hood or tarpaulin for protection. When the outdoor temperature exceeds +40°C, the rolls must be protected from sunlight.

Before installation, the rolls must be stored at a temperature of +15 °C, or warmer, for at least a day. The membrane rolls are unrolled in advance to straighten
out, which prevents bumps in the product. The time that the straightening out requires depends on the temperature (approximately 1 to 4 hours).