Spray Foam and Mortgages: Why Lenders Say No

Spray foam insulation was marketed as an energy-saving upgrade, and for several years it was heavily promoted and grant-funded. Yet many homeowners in Farnham and across the country now find it works against them the moment they try to sell, remortgage or insure. This guide explains why, in plain terms.

What changed

From around 2023, most major UK lenders and the surveyors who act for them tightened their approach to spray foam. It was not a single ban but a broad shift in caution, driven by concerns that had built up over years of installations.

What worries a lender

There are three linked concerns:

• Hidden timbers. When foam is sprayed onto the underside of the roof, a surveyor can no longer inspect the rafters and battens. They cannot confirm the roof is sound, so they flag it.
• Trapped moisture. Closed-cell foam in particular can seal moisture against the timber, and over time that risks rot. Because the timber is hidden, no one can rule it out.
• Future liability. Removing foam is skilled work, so the lender sees a property that may cost the next owner money — and prices that risk in, often by declining altogether.

What a surveyor actually looks for

A RICS surveyor wants to see the roof structure and confirm it is in good order. Spray foam prevents that. Where foam is present, the surveyor typically recommends either removal or a specialist inspection and report before the valuation can be relied upon.

How the problem is resolved

The route back to a mortgageable property is straightforward in principle:

1. Have the loft surveyed to confirm the foam type and roof condition.
2. Remove the foam cleanly if the report recommends it, exposing the timbers.
3. Treat any genuine timber issues found.
4. Obtain a written report confirming the work and the condition of the roof.

With the timbers visible and documented, the lender's three concerns fall away and the property is treated normally again.

A note on selling

If you are selling, it is often worth resolving this before you go to market, or at least being upfront about it. Buyers' lenders will raise the same objection, so a home advertised with a clear report and the foam already dealt with is a far easier sale.

If your own sale or remortgage has stalled over spray foam, request a free survey and we will explain exactly where you stand and what, if anything, needs doing.