Anyone can say a roof has spray foam in it. A report says which kind, where it runs, how far it extends, what is happening underneath it and what should happen next. That difference is what makes an assessment useful when a surveyor queries your loft, a lender hesitates, or you are weighing up whether to remove the foam at all.
This guide walks through the parts of a report in the order they usually appear, so you can tell a thorough one from a thin one. It is about the content of the document. If you want the detail on one element, our guide to inspecting roof timbers under spray foam goes deeper than we do here. Costs for the work that may follow are on the spray foam removal cost page, and the whole service is described under spray foam insulation removal.
Who asks for an assessment, and what it cannot be
People ask for a spray foam survey for different reasons. A seller wants evidence. A buyer has had a flag in their homebuyer report. An owner has noticed a musty smell in the bedrooms, or a mortgage broker has asked a question. Others simply want to know what the previous owner did.
The report is a record of condition and a set of recommendations. It is not a structural calculation, a legal opinion on whether a lender will accept the house, or a valuation. The Royal Institution of Chartered Surveyors (RICS) consumer guide of March 2023 expects a qualified professional to carry out the thermal and condensation calculations. Some questions, such as whether a roof's moisture balance stacks up on paper, may need a surveyor or specialist working alongside us.
What we do and what we pass on
Our survey covers the roof from the loft side and, where it is safe, from outside. We record what we can see and measure, photograph it, and say what we would do. Where the findings point beyond roofing, such as a damp wall or an insurance question, the report names that and suggests who to ask next.
MyBuilder's 2026 guide puts a typical national assessment at about £100 to £200. Should work follow, the quote for it comes after the survey.
Foam type and how it was fitted
The first thing a report identifies is the foam itself. Spray foams broadly fall into two families, usually called open-cell and closed-cell. Open-cell foam is soft and spongy to the touch. Closed-cell foam is denser, firmer and often has a harder skin. Our answer on open-cell and closed-cell foam sets out why that matters for removal.
What the report notes
- Type. Which family the foam appears to belong to, based on appearance, feel and how it has aged.
- Thickness. Measured at several points and recorded as a range, since depth varies.
- Finish. Whether it has a smooth, even surface or a rough, uneven one, and whether it has cracked, shrunk or pulled away.
- Where it sits. Sprayed onto the back of the slates or tiles, to the underlay, between rafters, over them, or to the loft floor.
- Any labels or paperwork. A product name, an installer sticker or a guarantee on the loft hatch can help trace what was used.
This is not trivia. How the foam was applied decides how it comes off, whether the covering can be reused and how long removal is likely to take. A report that skips this section cannot support a sensible quote.
Coverage: how much of the roof is foamed
Coverage is a plain question with a plain answer, and it drives the price. The report maps where foam has gone and where it has not.
What gets measured
We record the roof slopes involved, noting each one by orientation, and estimate the area in square metres, since removal is priced per m². MyBuilder's 2026 figures give a typical national range of about £20 to £50 per m², averaging about £1,500 for a job, with disposal and any repairs and re-insulation on top. A map and a measured area turn that range into a number for your roof.
Partial coverage
Some roofs have foam on one slope only, or on one extension. Others have patches around chimneys or valleys where an installer sprayed the awkward corners. Our answer on partial spray foam removal looks at when taking out part is enough. The report supports that decision by showing exactly where the boundary lies.
Awkward areas
Eaves, the zone around chimney stacks, party walls and the junctions where an old roof meets a newer one are recorded separately, because foam in these places is harder to reach and to inspect. A thorough report says where we could not see, rather than implying we saw everything.
Moisture, ventilation and signs of trouble
This is the section lenders and buyers read hardest, because the RICS guide names moisture as the main hazard. Its warning is that badly fitted foam can bring dampness, with condensation that nobody controls and damage elsewhere in the structure.
Moisture readings
Where timbers or boards are reachable, we use a moisture meter to take readings and note the pattern. We also look for staining, tide marks, softening, mould growth on exposed surfaces and any drips or damp patches on ceilings below. A single high reading is a prompt to look further, not a verdict, and the report says so.
Ventilation
Roofs without foam often rely on gaps at the eaves and the ridge to let air through. The relevant moisture code of practice is BS 5250, and manufacturer guidance describes small continuous gaps at the eaves and sometimes at high level, depending on pitch and span. The report records whether any such route still exists, whether foam has blocked it and whether vents, tiles or fascia details have been altered.
Signs from outside
On the roof itself we note slates and tiles that have slipped, cracked or gone, flashings and lead that are failing, and gutters that are blocked, because those are the routes by which rain gets in. Our answer on spray foam and condensation explains how moisture builds up in a foamed roof. If the signs point to a leak instead, the report records that, since the remedy differs.
Timbers: what can and cannot be said
Foam hides the timbers it touches, and that is the weak point of many reports. It is also the reason we explain our method in the report itself, so that a reader can judge how far to rely on each finding. Nobody can pronounce a rafter sound while it is buried under a layer of set foam.
What can be recorded
We inspect every timber that can be reached: the rafter feet resting on the wall plate, ceiling joists, purlins and gable ends, and any section where foam has broken away or been cut back. We look for discoloration, softness, insect flight holes, cracking and distortion, and photograph anything unusual.
What cannot
Under unbroken foam, a timber can only be assessed from the surface that shows, from moisture readings through the foam where an instrument allows it, and from signs on the other side such as stained ceilings. The report states which timbers were seen and which were not.
Where the evidence is uncertain, the sensible recommendation is often a staged one: remove a trial area of foam in a low-risk spot, look at the wood, and decide the rest from what is found. That is more useful than a blanket statement either way, and it fits the RICS position that removal is not automatic. For the full method, see the timber inspection guide.
A report that declares timbers sound without saying how they were checked is a weak document. Look for the method as well as the conclusion.
Recommendations: leave, monitor, part-remove or remove
The last section is the one most readers turn to first. It sets out what we would do, and why, in plain terms.
The usual outcomes
- Leave and monitor. Timbers dry, covering sound, ventilation adequate. The report recommends a re-check at a stated interval and keeps the evidence on file.
- Part-remove. A defined area, such as one slope or a damp zone, comes out and the rest stays.
- Remove. The foam comes off by hand, the timbers are inspected and treated if needed, and the roof is re-insulated.
- Refer on. A specialist such as a chartered surveyor or timber and damp specialist is asked to look at something beyond a roofer's remit.
How it is priced
Removal comes with national ranges for disposal, about £150 to £400, and for repairs plus new insulation, about £500 to £3,000 (MyBuilder, 2026). Your own figures come in the quote we write once the survey is done, covering scaffold, removal, disposal, repairs, re-insulation and making good.
No recommendation says foam must always come out. Our answer on whether spray foam must be removed covers that position.
Using the report with a lender, buyer or insurer
An assessment earns its fee when someone else reads it. The audience changes what to emphasise.
Lenders and brokers
As of November 2024, news reports based on a BBC investigation described some lenders refusing homes with foam and others looking at each case. A broker may ask for the report to support an application, and our guide to spray foam and equity release covers the later-life lending side.
Buyers and sellers
For a seller, the document turns an unknown into a known condition. For a buyer, it separates a harmless coating from a live problem. Either way, the dated photographs from your own roof are what people look at first, and they are quick to read even for someone who has never been in a loft.
Insurers
RICS says to check with your insurer whether the policy allows foam. Send the report if they ask, and keep their reply on file alongside it, because a policy wording can change between one renewal and the next and you will want proof of what was agreed.
Next steps with us
If you want an assessment, the number is 01453 933613, and WhatsApp or the enquiry form work too. Tell us the address, the roof type and whether the loft hatch is easy to reach. On the day we take pictures of your own roof and write up the findings in the order set out above. Any work that follows carries a 10-year workmanship guarantee in writing, and we finish with the site cleared and the waste gone.