They can also be used if two materials are chemically incompatible. The
same materials can be used as for the levelling courses.
Vapour barriers are used to regulate moisturetransmission inside
the building. > Chapter Pitched roofs, Types of finish They are not waterproof, but
simply inhibit vapour diffusion. The inhibition factor indicates how much
moisture can diffuse through the vapour barrier. They can be bitumen
roofing sheets, plastic vapour inhibiting sheets, elastomer roofing sheets,
or compound foils. They can be laid loose or spot