Wethan 280

Waterproofing, thixotropic, fibre-reinforced, UV-stable 1C polyurethane resin

Brief Description

Wethan 280 is a high-grade, thixotropic, fibre-reinforced 1C polyurethane resin for the flameless waterproofing of junctions, upstands and edges. As a highly elastic flashing product, Wethan 280 is tested, approved and classified in accordance with ETAG 005 as a category W3 product (minimum service life of 25 years).


1-component, highly elastic, thixotropic, polyurethane-based waterproofing resin with fibre additives

RAL colours

Wethan 280
is available in the following standard colours:



This product can be used on practically any flat roof. Areas susceptible to cracking, such as upstands, wall junctions, dome lights etc. can be permanently integrated in the waterproofing system without the need for an additional fleece. The junctions between different materials such as bitumenised sheets, PVC membranes, concrete/mortar/screed, various metals, wood etc. can be permanently waterproofed. Designed for residential, commercial and industrial developments with light-duty mechanical and chemical exposure. Wethan 141 is used as a primer on absorbent substrates such as concrete, stone or wood. Non-absorbent substrates, such as bitumenised sheets, metals, PVC etc. can be waterproofed without the need for a primer. (Please refer to the Weplus substrates table. Wethan 280 absorbs substrate movements due to temperature fluctuations between – 30 °C and + 80 °C (depending on the layer thickness applied). Wethan 280 is supplied ready for use. Additional fillers should never be added, as this would reduce the flexibility of the membrane. When fully cured, Wethan 280 is resistant to water, seawater and waste water as well as to numerous alkali solutions, diluted acids, salt solutions, mineral oils, lubricants and fuels, and to many solvents. Depending on the substance, concentration and duration, exposure to chemicals may result in superficial colour changes, although this will not affect the reliable function. Polyurethanes with this composition have a strong tendency to change colour under the influence of UV radiation.

Properties and advantages

  • When cured, Wethan 280 forms a seamless, fibre-reinforced elastic and waterproof membrane. Wethan 280 possesses good water-vapour diffusion capacity. The waterproofing is UV-resistant and offers good chemical and mechanical resistance.


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Postal address

WestWood Liquid Technologies Ltd.
31 Morris Road,
Nuffield Industrial Estate
Poole, Dorset BH17 0GG
United Kingdom

+44 800 808 5480

Trade Association

  • LRWA
  • DIBt
  • NFRC
  • EOTA
  • BPA
  • BBA