Spray foam insulation found on a survey: what UK lenders do and what to do next
Spray foam on the underside of a roof is one of the few survey findings that can stop a mortgage however little it costs to fix. It isn’t automatically a disaster, but it has to be sorted out before exchange. I’m Ben Murrell, a builder for nearly 30 years. This is the order I’d tackle it in.
Last updated September 2026 · UK
Why lenders care about spray foam
Spray foam sprayed between the rafters turns a ventilated “cold” loft into a “warm” roof. Done badly, or on the wrong roof, it can trap moisture against the timbers. Because the timbers are covered, a valuer or surveyor can’t see what state they’re in (RICS consumer guide).
When the BBC asked the 20 largest UK lenders about spray foam in November 2024, some said they did not lend where spray foam was found in the roof space, some said they would not usually lend where there was a significant amount, and others said they looked at cases individually and might ask for installation documents or a specialist report (BBC News, 18 November 2024). Lender policies have kept changing since then, so don’t rely on any published list. Check your own lender’s current policy through your broker before you exchange.
Open-cell foam stays soft. Closed-cell foam sets rigid and was sometimes sold to “stabilise” failing roofs. The BBC report covers the difference. RICS also says its guidance doesn’t cover foam that was designed into a new-build roof or a properly designed loft conversion. Those are treated differently.
How worried should you be?
- Less worried: the seller has full documentation, the foam was installed to the manufacturer’s method, an independent inspection finds dry, sound timbers, and your lender accepts it.
- More worried: no paperwork, foam sprayed straight onto the back of tiles or onto bitumen felt (RICS flags both), signs of damp or rot, or a lender who won’t lend.
- Listed building: RICS says spray foam needs listed building consent in advance. Without it, get conservation and legal advice.
What to ask the seller, your surveyor and your lender
- Seller (through your conveyancer): when and why the foam was fitted, which product, who installed it, the contract, calculations, warranty or guarantee, and any BBA/Kiwa certificate. The HomeOwners Alliance suggests flagging it with your conveyancer so they get the right guarantees and paperwork (HOA).
- Surveyor: which type of foam they think it is, where it is, whether they could see any timbers, and whether they recommend a specialist inspection.
- Lender (through your broker): whether they’ll lend with the foam in place, what evidence they need, and whether they require removal.
Typical next steps, in order
- Ask your broker whether your lender will proceed, and on what evidence. This decides everything else.
- Get the paperwork from the seller.
- Book an independent spray foam inspection, from someone who doesn’t install or remove foam, that follows the PCA protocol.
- If removal is needed, get at least two independent quotes, and ask whether the roof covering or felt will need replacing at the same time. That’s often where the real cost is.
- Take the evidence back to the seller: a price reduction, the seller arranging removal before exchange, or a split.
On cost: I’m not going to give you a national figure, because removal depends on the foam type, the roof size and whether the covering has to come off. As one example, the BBC reported a family who replaced the whole roof at a cost of nearly £10,000, which they split with their buyers (BBC News). Get the job priced for your roof.
Beware cold callers. RICS and the BBC both warn about unsolicited offers to remove spray foam. Don’t let a removal firm be the one that “inspects” it.
If this is one problem among several, read should I pull out after a bad survey? If the lender has offered a mortgage with money held back, see mortgage retention on a valuation. For the roof itself, the roof replacement cost calculator and our guide to an aged roof covering give our typical ranges.
Frequently asked questions
Can I get a mortgage on a house with spray foam insulation?
Sometimes. It depends on the lender, the type of foam and the paperwork. When the BBC asked the 20 largest UK lenders in November 2024, some said they did not lend where spray foam was in the roof space, while others said they would consider cases individually, often asking for installation documents or a specialist report. Policies change, so check your lender’s current position with your broker before you exchange.
What paperwork should I ask the seller for?
RICS recommends having the installation contract, relevant calculations, details of works to the roof, any guarantee or warranty and any independent certificate such as BBA or Kiwa. Ask for it through your conveyancer as early as possible.
Does spray foam always have to be removed?
No. Some lenders will accept it with documentation or a satisfactory specialist inspection. Removal becomes likely where the lender insists, the timbers show damp or decay, or the foam was applied in a way RICS warns against, such as directly onto tiles or onto bitumen felt.
Who should inspect spray foam?
Someone independent of the installer, the manufacturer and any removal company. The Property Care Association published an inspection protocol for pitched roofs in 2023 to help surveyors and lenders assess the risk.
Does Chat to Your Builder remove spray foam?
No. We review your RICS survey and explain what the finding means, the likely routes and what they usually involve. We never quote for or carry out the work.
Sources
Free tools that go with this
Translate the report, price the findings, and work out what the whole purchase costs.