Spray foam insulation is not used as an internal waterproofing product on domestic roofs. When working on domestic roofs, our installers will carry out all necessary roof repairs before installing foam insulation, this allows us to guarantee the roof for 25 years against water ingress. Foam insulation is used to bond the roof after we have carried out any necessary repairs, our installers will make your roof waterproof before the foam is applied.
When used externally on industrial buildings or similar, foam insulation can be used to waterproof a roof. This is only when the foam is applied externally and covered in a suitable coating, this is not recommended for domestic roofs.