Spray foam insulation was once promoted as a modern solution for energy efficiency, reducing heating bills and improving EPC ratings. Unfortunately, it’s now one of the most common reasons UK property sales collapse.
If you’re an estate agent, homebuyer, or homeowner looking to sell, you need to understand why spray foam insulation causes problems and, more importantly, how to fix them.
Why Spray Foam Is a Deal-Breaker in Property Sales
Mortgage refusals – The majority of UK lenders will not approve mortgages on homes with spray foam loft insulation.
Surveyor red flags – RICS surveyors consistently down-value homes with spray foam because it:
Blocks ventilation
Traps moisture
Makes roof structures impossible to assess properly
Buyer hesitation – Even cash buyers often walk away, fearing hidden costs or roof damage.
Insurance difficulties – Many insurers won’t cover properties with spray foam, leaving owners exposed.
👉 In short: spray foam insulation makes a home unmortgageable until it is removed.
How This Affects Estate Agents
Estate agents are often the first to feel the pain:
Sales collapse when the buyer’s lender refuses the property.
Chains break because one house in the chain has spray foam.
Valuations come in lower, frustrating both buyer and seller.
Forward-thinking agents are now identifying spray foam early and guiding homeowners to get it removed before listing. By doing so, they prevent wasted time, avoid fall-throughs, and restore confidence for buyers and lenders.
What Homebuyers Need to Know
If your survey report highlights spray foam insulation, don’t panic — but don’t ignore it either.
Identify the foam type – Is it open cell (soft) or closed cell (hard, rigid)? Closed cell is more problematic.
Understand removal costs –
Open cell: £50–£60 per sqm
Closed cell: £75–£90 per sqm
Negotiate – You may be able to ask the seller to pay for removal or reduce the asking price accordingly.
Insist on certification – If removal has already been carried out, ask to see the spray foam removal certificate. Without this document, lenders may still refuse the property.
How Homeowners Can Protect Their Sale
If you’re selling a home with spray foam, it’s best to deal with the issue before listing.
Get a professional inspection. A spray foam removal company will confirm the foam type and condition.
Have the foam safely removed. Manual removal only – no dry ice blasting, no re-roofing.
Obtain a spray foam removal certificate. Signed by the company director, this proves to buyers, lenders, and insurers that:
The foam has been fully removed
Ventilation has been restored
Membranes remain intact
Timbers have been inspected and treated
With the certificate in hand, your property becomes mortgageable again — preventing sales from collapsing and giving buyers confidence.