Spray foam under a roof can turn a routine mortgage into a stalled one. Sellers meet it when a buyer's lender declines the valuation. Owners meet it on a remortgage that was meant to be a formality. In both cases the question is the same: will the lender accept security that includes a roof it cannot inspect?
This guide is about the lender's side of that question. It covers what was reported in November 2024, why the refusals happen, what case by case means in practice, and what kinds of evidence move an application forward. It does not tell a buyer what to do step by step, which is the subject of buying a house in Stroud with spray foam. Lender policy changes without notice, so treat everything here as a dated snapshot and confirm the current position directly. The wider service is described at spray foam insulation assessment and removal.
The November 2024 snapshot
In November 2024 Today's Conveyancer reported on a BBC investigation into how lenders treat homes with spray foam. Its summary was that a group of lenders, including an equity release provider, would not lend on a property where the foam is installed. A second group told the investigators that they would take applications on a case-by-case basis. We describe this as some lenders declining and others assessing each case, and we leave the names to the original report, because positions shift and a list printed today can be wrong next quarter.
What the snapshot tells you
It tells you the market was split. There was no single rule across lenders, which means the answer for your house depends on who is lending and when. It also tells you that a refusal is a policy decision about the product, which is different from a finding that your own roof is damaged. A lender with a no-foam rule does not need to know whether your timbers are dry. It declines the category.
The gaps in the report
Nothing in it says that foam is unmortgageable, that lenders will never reconsider, or that removal is always required. None of it comes from a trade body either. The wording we use on every page of this site is deliberate: some lenders, a date and a source. If you need to know where a specific bank stands, phone them or ask your broker, and get any answer confirmed on paper.
Why a lender says no
From the outside a refusal can look arbitrary. Seen from the lender's desk it follows a chain of reasoning, and understanding the chain shows which parts you can influence.
The roof is part of the security
A mortgage is secured against the whole building. The lender needs to be confident that the structure will still be there in twenty-five years, and the roof timbers are structure. Rafters, battens and boards are normally checked by looking, probing and sometimes drilling a moisture reading. With foam sprayed across the underside, none of those checks is straightforward.
The risk that cannot be seen
The RICS consumer guide warns about uncontrolled condensation from incorrect installation. If condensation did occur, the first sign might be timber decay behind the foam, long before a stain reaches a ceiling. A valuer cannot rule that out from the loft hatch, and a lender cannot price a risk that nobody can measure.
The cost of putting it right
Even where the roof is sound today, the next owner inherits a difficult inspection. If a problem develops, the foam must come off before the timbers can be reached. Lenders, who sell repossessed properties as a last resort, take that into account when they decide what they will accept as security. The practical cost of removal is set out in what spray foam removal costs.
Concerns that sit alongside
Insurers and surveyors react to foam as well, and a lender is influenced by both. A surveyor's recommendation for specialist inspection is often what prompts the underwriter to hold the application. Our look at the RICS guidance shows where those recommendations come from.
What case by case means in practice
The lenders that said they would consider foam on an individual basis did not say they would approve it. A case-by-case policy means a person reads the file, and what is in the file matters. That is good news for anyone who can supply evidence and poor news for anyone who cannot.
A trigger in the valuation
The process usually starts with the valuer. If the surveyor notes foam and recommends further investigation, the lender may make the offer subject to a satisfactory report from a specialist. It may also reduce the loan, defer the decision, or decline. We cannot tell you which, because it is the lender's choice. The common thread is that the file has to resolve the surveyor's question.
Who writes the report
The lender will normally want a qualified person, independent of the seller where possible, to inspect the roof void. Roofers can supply that inspection. The report should record what was found and what could not be seen, and it should not be dressed up as more than it is. A lender reads dozens of these, and padding is spotted quickly.
Timing
Because every step takes time, a case-by-case lender can delay completion on a purchase. That is why evidence is best gathered early. If you are selling, an assessment you commissioned yourself puts a document in the buyer's hands before their lender asks. See selling a house with spray foam for the seller's view.
Ask the lender what it would accept before commissioning any report. A report written to the wrong brief can cost the same as one that works.
Evidence that helps an application
Lenders respond to documents. Anything that replaces an unknown with a measured fact helps, and the more specific the better.
Records from the installation
Product data sheets, the thickness applied, the surface it was sprayed onto and the installer's invoice all help. Strongest of all is a calculation of heat loss and a moisture-risk check made by a qualified professional before the foam went on, which is the step the RICS guide asks for. If you hold these, they are the strongest paper you can show.
A moisture and condition report
When records are missing, a survey of the roof void as it is today fills the gap. Ours identifies the foam type, measures thickness, notes what it is stuck to and takes moisture readings in each timber within reach, and photographs your own roof as we go. Where we cannot reach a timber, the report says so plainly instead of implying a clean bill of health. Type matters, and open-cell and closed-cell foam are read differently.
Roof ventilation and the covering
Evidence about how the roof breathes, and the state of the tiles or slates above the foam, shows the lender the foam is not sitting on a failing covering. Photographs from inside and outside make the point better than a paragraph.
Insurer confirmation
Because the RICS guide tells owners to check with their insurer, a short written confirmation of cover is worth adding to the file. Lenders like to see that the building can be insured on normal terms.
What does not help
General statements that foam is fine, marketing claims from product suppliers and verbal reassurance do not persuade an underwriter. Specific readings, dates and photographs do.
When removal becomes the sensible route
Removal is not the first thing to reach for, and the answer on whether spray foam must be removed explains why. But some situations point that way. The assessment may show wet timbers. The lender may be one of those declining the category outright. The buyer's lender may insist on removal as a condition. In those cases, taking the foam off and fitting insulation that the roof can breathe through resolves the lender's question by removing the thing it objects to.
What the lender then sees
After removal the timbers are exposed and can be inspected, so we photograph them before the new insulation goes in. A set of dated photographs, moisture readings and a description of the new build-up is a document a valuer can read. It shows that the problem was found and dealt with, which is a stronger position than showing that it was argued about.
Doing it in the right order
If a sale or remortgage is pending, agree the sequence with your solicitor and the lender so the work is accepted as the answer. The method, from first cut to final checks, is described in how spray foam is removed from a roof.
Notification and VAT
Some of this work is notifiable under the Building Regulations, and when it is we send the notice to building control ourselves. The Planning Portal thresholds for roof work are 25 per cent of the building envelope and 50 per cent of the roof. On VAT, the insulation itself is zero-rated in a dwelling until 31 March 2027, while the stripping is standard-rated, and the quote states the VAT rate that applies.
Equity release, remortgaging and keeping the paper trail
Not every mortgage conversation is about buying. The November 2024 report named an equity release lender among those declining foam, so a later-life borrower faces the same question under different rules. Equity release products are long-term and the lender holds the property for many years, which is one reason the roof matters to them. We cover this in spray foam and equity release.
Remortgaging
A remortgage often triggers a fresh valuation, and with it a fresh look at the roof. An owner who has lived happily with foam for years can be caught out. The advice is to ask the new lender about foam before paying any fees, and to avoid assuming that your current lender's silence means anything about a different one.
Keep a file
Whatever route you take, keep one folder, paper or digital, with installation records, any assessment, photographs, correspondence with lenders and insurers, and invoices. Each document answers a question that someone, later, will ask. The folder transfers to the next owner and saves them the work.
What we do and do not do
We inspect, report, remove and re-insulate. We do not negotiate with your lender and we cannot guarantee how a lender will respond. What we can give you is the roof evidence. Once we have surveyed, you get a written quote for the whole job. Our workmanship guarantee runs for 10 years and is issued on paper, and the waste leaves with us.
If a lender has already named the foam, send us its wording along with photographs from inside the loft. Those tell us which questions the survey must answer.