The short answer
Yes. Spray foam is easy to see from the loft hatch, because it coats the rafters and the inner face of the covering in one continuous layer. What an inspection cannot do is see through it. The timbers, battens and underlay behind the foam stay hidden, so we record where it is, photograph it and tell you what we could not check.
Spotting foam in a loft is easy once you look up. The harder question is what it covers, and what a lender will say about it.
How foam shows up in the loft
The loft check is where spray foam is found. Where you would expect bare timber and the dark back of the covering, you see a sprayed skin that follows the slope from eaves to ridge, with no gaps between the rafters. Insulation laid on the loft floor looks entirely different, so the two are easy to tell apart, even in a dim loft with only a torch.
What do we record when we find it?
We photograph the foam where it starts and stops, note if the layer runs across every slope or only some, and look at its surface for cracks, gaps or places where it has pulled away. We also look at the edges, the eaves and the area around the chimney, where the foam often meets masonry.
The foam is described in the report as it is seen. We cannot say how thick it is without cutting into it, and who applied it, and when, is for the owner's paperwork to say. If paperwork from the original installer exists, the owner is the best person to find it, and we are glad to read it alongside the photos.
What the foam hides from an inspection
This is the limit that matters. A roof inspection from inside normally relies on seeing the timbers and the back of the covering, because that is where a slow leak leaves staining, rot and daylight. Once those surfaces are covered, a leak can continue unseen.
Can a leak go undetected under foam?
It can. Water that gets past a cracked slate or a worn flashing meets the foam rather than open air, and it may sit against the battens and rafters without showing in the loft. Staining on the ceiling below, or damp showing on the foam itself, are clues, but they are not certain.
Energy Saving Trust advice on a roof that already leaks is blunt: "We don't recommend doing this" (last updated 8 May 2026). Trapping damp under foam is the risk it points to. Where we cannot see behind the foam, the report says so in plain words, and we check the outside of the roof carefully, because the covering, ridge, valleys and flashings are still visible from above. Timber that stays damp behind foam can rot unseen for years, which is why a clean outside matters so much.
Spray foam, mortgages and your lender
Spray foam has become a talking point when homes are bought and sold. The RICS consumer guide on spray foam tells buyers to put the question to their mortgage provider: does the lender's policy permit such products at all? That is advice for you, not something a roofer can settle.
Should I ask my lender before I buy or sell?
Yes. If you are buying a home with foam in the loft, ask your mortgage provider and your solicitor what they need to see before you commit. If you are selling, find out early whether the buyer's lender may raise the point, so it does not land as a shock halfway through.
Our inspection supports that conversation with evidence. The photos show the extent of the foam and the condition of the outer roof, and the written notes say what could and could not be seen. We do not give lending advice, and nowhere does it say the foam has to come out. Whether to keep it is a decision for you, your lender and your adviser once you have the facts, and the report gives you a clear record to take to each of them.
If the foam has to come out
Sometimes the inspection finds a reason to look further, such as damp behind the foam or a lender's condition. Removal is its own specialist job, separate from the roof survey and priced on its own merits, and we cover it on our spray foam removal page.
What sets the cost of taking foam off?
The amount of foam, how it was applied, the state of the timbers beneath it and the access to the loft all set the cost. We cannot give a sensible figure until we have seen the roof, so the price comes after a survey, as one total in writing.
What happens next is straightforward. After the foam is taken off, the timbers can be checked, any rot dealt with and the underside of the covering inspected, often for the first time in years. Owners are often relieved to see timber they were never sure about. Our guides to checking a roof from the loft and the roof inspection report explain what you will receive, and our main roof inspections page is the place to book.
Foam and roof checks
Can you tell from outside whether a roof has spray foam under it?
No. From the outside the tiles and slates look the same either way. The foam is found from the loft, where it coats the rafters and the back of the covering. If you are unsure, say so when you book and the loft check joins the visit.
Does finding foam mean the roof is leaking?
No. Foam on its own says nothing about leaks. The concern is that it hides the timbers, so a leak would be harder to spot, and a hidden leak is harder to fix cheaply. We check the outside covering, ridge, valleys and flashings closely, and report what we could and could not see.
The full picture: Roof inspections in Taunton ยท More short answers