Does spray foam affect home insurance?

In March 2023 the Royal Institution of Chartered Surveyors issued a consumer guide covering spray foam insulation. Among its do and do not points, it tells homeowners to check with their insurance provider whether the policy allows the installation of such products. It sits alongside a matching instruction to ask your mortgage provider about its policy.

That is the extent of what the guide says on insurance, and it is worth being exact about it. It does not state that insurers refuse cover, that premiums rise or that any named company has a particular position. What it tells you is that the policy wording and the insurer's own rules are what count, and that the time to find out is before the work, not after a claim.

The same guide points out that badly fitted foam can cause damp where condensation goes unmanaged. That is the kind of damage an insurer could ask about, which is one reason why the paperwork behind a foam installation matters. Lenders are dealt with separately, in our guide to spray foam and mortgages.

A phone call is a start, but a written answer is worth more. Ask your insurer, by email or letter, whether your policy allows spray foam insulation in the roof, whether foam that is already there needs to be declared, and whether the answer changes with the type of foam. Ask also whether the position is different for buildings cover and for contents cover, since the two are often written separately.

If you are removing foam, ask whether the insurer wants to be told, whether it wants a report from the contractor, and whether it needs to see evidence that the timber was found sound. If you are claiming for water damage and foam is present, ask how it is treated. Keep the reply with your house papers. A short note from an insurer, dated and specific to your address, is the sort of document that saves an argument later.

Which way any given insurer will jump is not something we can say, and we do not guess. What we can do is supply the roof side of the evidence. Our page on whether spray foam always has to be removed explains how that evidence feeds into the decision.

Insurers and surveyors both work from documents. The useful ones for a roof with foam in it are the installer's invoice and product data, any thermal calculation or condensation risk check done before the foam went in, and a survey of the roof timbers carried out afterwards. RICS wants condensation risk checks made by someone qualified ahead of installation, so if yours exist, keep them safe.

If they do not exist, a timber inspection now serves a similar purpose. We photograph the foam and the wood where we can reach it, take moisture readings and describe what we find. Where a section of foam is cut back to see the timber behind, that gets recorded too. For a deeper look at what such an inspection covers, see our guide to inspecting timbers behind spray foam.

If the foam is later removed, the removal record adds a before and after picture: the state of the rafters under the foam, any repairs, and the new insulation fitted. That combination is stronger than any single statement, and it costs far less than arguing over a claim without it. MyBuilder's 2026 guide puts an assessment at £100 to £200 nationally, which is modest next to the sums involved in a damp claim.

It helps to keep three conversations apart. Your insurer decides whether it will cover the building and on what terms. Your mortgage lender decides whether it will lend against it. A valuer or surveyor reports on its condition for one of those parties. An answer from one does not bind the others, and a lender that accepts foam does not mean an insurer will, nor the other way round.

On lending, Today's Conveyancer reported in November 2024, from a BBC investigation, that some lenders declined foamed homes and others reviewed them individually. That is lender behaviour, and we have no comparable sourced reporting on insurers. If an adviser tells you what insurers in general do, ask where it comes from.

Where foam is flagged during a sale, the practical steps usually run through the surveyor first, then your lender, then your insurer. Our page on what to do when a surveyor flags spray foam walks through that order.

Removing foam does not usually require you to do anything special with an insurer beyond what the policy says, but telling them is sensible if the foam was ever on record. The same goes if the work leads to repairs or a re-roof. Our answer on whether spray foam means replacing the roof explains when a whole new covering is needed and when it is not.

Cost-wise, removal sits in a typical national band of about £20 to £50 per m², averaging around £1,500, according to MyBuilder in 2026, with repairs and new insulation at £500 to £3,000. Your quote will show VAT, and our page on VAT on spray foam removal explains how the rates differ between the removal and the new insulation.

Send the photographs and any paperwork you hold, and we survey the roof and report on it. The quote that follows covers every element, the work is covered by a 10-year workmanship guarantee in writing, and we remove the waste. You can read about the full service on the spray foam insulation removal page.