Single ply membranes are offered in a limited range of standard colours, usually a selection of greys. Non-standard colours are available subject to minimum order quantities and extended lead times.
As well as naming the colours of their single ply membrane, waterproofing manufacturers commonly also use the closest matching RAL number, to allow for more accurate specification. Two different manufacturers might have a ‘dark grey’ in their range, so a RAL number gives a specifier more certainty about how they compare.
For example, in IKO Polymeric’s range, the Armourplan membrane is available in Mid Grey (RAL 7046), Slate Grey (RAL 7015) and Light Grey (RAL 7047). The Spectraplan membrane, meanwhile, is available in Light Grey (RAL 7035).