In 40 seconds
Spray foam insulation is removed mainly because many mortgage lenders and surveyors are cautious about it: once it is applied to the underside of the roof it can obscure the timbers and reduce ventilation, so a surveyor cannot easily confirm the roof is sound or free of condensation and decay. Foam is not automatically dangerous — correctly specified, ventilated and installed foam can perform — but problems arise where it traps moisture against timbers or hides defects. Whether yours needs removing depends on the foam type, install quality, ventilation and the timbers’ condition. Professional removal typically costs £2,000–£5,000+, but an independent inspection (from a RICS surveyor or qualified specialist who does not profit from removal) is far cheaper and should always come first. RICS published guidance in 2023 to help surveyors assess foam more consistently.