My surveyor flagged spray foam: what now?

RICS, the professional body for surveyors, publishes a consumer guide on spray foam, and it says foam in a roof can bear on a surveyor's view of what a property is worth. That is the main reason it shows up in reports. A surveyor cannot see the rafters behind a layer of foam, so they cannot confirm the timber is dry, and they have to say so.

The same guide explains that poor installation can lead to damp, uncontrolled condensation included. It also says a suitably qualified person should carry out condensation risk and thermal calculations ahead of installation. If the seller has nothing to show for those checks, the surveyor will usually record that too.

So the flag typically means unknown condition rather than defective roof. Your job is to turn the unknown into something specific that a lender, an insurer and a seller can respond to. The wider picture is on our spray foam insulation removal page.

Start by going back to the surveyor with precise questions, ideally by email or phone within a day or two of reading the report, while the visit is fresh in their mind. Which roof slopes are foamed? Did they see open-cell or closed-cell foam? Was there staining, a smell or an elevated damp meter reading? Ask for the answers in an email so there is a record.

Next, ask the seller's agent for whatever the seller holds: the installer's name, the date, any guarantee, an invoice, a condensation risk calculation and a note of any lender or insurer consent. Our page on whether a spray foam certificate exists explains why the paperwork is often thin.

Then arrange an independent roof void inspection before exchange. We can examine the foam, the visible timbers, the ventilation and the covering outside, and report back with photographs and a written quote for removal or repair. That single document gives you hard evidence for the price conversation with the seller, and something your broker can pass to a lender.

Lenders and insurers matter here because they can change what is possible. As of November 2024, a BBC investigation reported by Today's Conveyancer found that a group of lenders were declining mortgages on foamed homes, while another group judged every application separately. Positions move, so the only reliable check is to ask your own lender, and to ask before you go further.

The RICS guide gives the same advice: ask your mortgage provider if its lending policy allows such products, then ask your home insurer the same. If your lender refuses or wants the foam dealt with, a written roofing report and quote gives your broker material to work from. We do not handle mortgage or insurance applications, and nobody can promise how one will turn out, but the report shows the real condition of the roof.

Two further guides are useful at this point: restoring roof ventilation after removal shows what the repair work might involve, and spray foam and roof condensation shows the problem a surveyor has in mind.

Three outcomes are realistic. If the foam is sound, the timber behind it is dry, the roof breathes sensibly and the lender is content, the foam can stay. If there is doubt, a limited section can sometimes be opened up so the timber can be examined. Our page on partial spray foam removal sets out when that works and when it does not.

If the survey turns up moisture, rot or failed foam, removal and re-insulation is usually the answer. MyBuilder's guide, updated in August 2026, gives typical UK figures of £20 to £50 per square metre for removal, averaging around £1,500, plus £500 to £3,000 for repairs and new insulation. These are national figures, so use them for orientation only. Our quote follows the survey, and whatever quote you hold, find out if it includes VAT and the scaffold.

Removal is not always the quickest route to a sale, but it is often the cleanest way to end the doubt. Where Building Regulations notification applies, we talk you through the consents and file it, so the buyer inherits clean paperwork.

If you are mid-purchase, this sequence keeps you out of trouble. Get the surveyor's reasons in writing. Ask the seller for installer paperwork. Check with your lender and insurer. Commission an independent roof void inspection. Then use the written quote to negotiate the price, ask the seller to put the work right, or walk away if the cost and risk do not suit you.

If you already own the house and the report came out of a remortgage, the first three steps are the same, and you control the timing of the rest. In either case, a few weeks spent establishing the true condition of the roof usually costs less than buying a problem unseen, and it gives you a firm footing in any conversation with the other side.

To book an inspection, phone 01793 626096, write to us on WhatsApp or send the enquiry form, and paste in the surveyor's wording if you have it. Our work carries a written 10-year guarantee, and we leave the property tidy.