Derbibrite waterproofing  system

Derbibrite is a multi-layer waterproofing system for warm, flat roofs on new build or refurbishment projects.

The membrane is a 3 mm thick, acrylic copolymer blend with glass-fibre and polyester reinforcement. It has a non-textured, integral acrylic surface.


The standard specification, applicable to timber, metal or concrete decks, is for the Derbibrite membrane to be cold bonded to the insulation, which is laid on an Alumasc Nilperm vapour barrier bonded to the deck in hot bitumen.

General information

Uniclass 2015

Ss_30_40_30_80 Single layer sheet warm roof covering systemsPrimary


J41/110 Built-up reinforced bitumen membrane warm deck roof covering

Specification data - Single layer sheet warm roof covering systems

Product Reference

Derbibrite waterproofing system

Vapour control layer

Nilperm vapour barrier


Derbifoam polyurethane GTF

Derbirock mineral wool

Waterproof membrane


Product Options


- Derbifoam polyurethane:

  • For warm, flat roofs. Suited to both new build and refurbishment applications. Available with one of three facings, to suit a wide range of waterproof membranes.
  • Thermal conductivity: 0.025–0.927 W/m²K.
  • Compressive strength: 150 kN/m².
  • Density: 32 kg/m³.
  • HFC and CFC free.
  • Tapered system available.

- Derbirock mineral wool:

  • Non-combustible insulation, with good noise absorption, making it suitable for use near airports and other noise sources.
  • Thermal conductivity: 0.038 W/m²K.
  • Compressive strength: 60 kN/m².
  • Density: Upper 15 mm face, 210 kg/m³; Standard element, 130 kg/m³.
  • HFC and CFC free.
  • Tapered system available.

Waterproof membrane:

Derbibrite: A modified bitumen membrane with a brilliant white, highly reflective finish. UV resistant, 3 mm thick.

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