Spray foam and lenders
Nothing on the visit sampled spray foam, opened one dormer cheek only or tested the rafters still hidden on the main slope. What has to stay undecided?
The main-slope rafters, and the spray foam on them, have to stay undecided. Nothing on the visit sampled the foam. One dormer cheek only was opened, which is a side face of the dormer, not the main slope. Rafters still hidden on that slope were not tested. A look into one cheek does not show the timber, the fixings or the covering on the rest of the roof. The survey has recorded the limit of that opening. It has not decided that the hidden roof is sound, and it has not decided that it has failed.
Last reviewed 24 October 2026. Written for buyers in England and Wales unless this answer says otherwise. No named surveyor has signed this page. It is general guidance, not a report on your house, and not legal advice.
What is the fuller explanation?
Spray foam sticks to the rafters and fills the space a surveyor would use to see the timber. Opening one dormer cheek reaches only that small void. The main slope can remain fully coated, so nail heads, damp stains on the wood and the condition of the felt or boarding stay out of sight. The visit did not cut a sample from the foam and did not describe a test of those hidden rafters. One opened cheek is a limit, not a tour of the roof.
Tell the solicitor the foam was not sampled and the main slope stayed hidden. If a lender asks about sprayed roofs, that question is for the lender's own criteria, which this report does not invent or satisfy. A roofing firm would need a separate instruction to expose timber. Do not brief them that the cheek opening cleared the slope. The survey has left the hidden rafters undecided, and the papers should say that plainly.
What should you ask your surveyor?
- Was only one dormer cheek opened, with the main slope left coated?
- Was any sample taken from the spray foam?
- Which rafter defects stay unseen because the foam was left in place?
What are the typical next steps?
- Keep the main-slope rafters as not inspected under the foam.
- Tell the solicitor the cheek opening did not sample the foam.
- Do not tell a lender the hidden roof timber was cleared.
Costs vary with the building and with who you instruct. Where this page does not cite a published figure, ask the surveyor, a relevant specialist, or your solicitor for a written quote. Do not treat a forum average as the price.
Also asked about this
Does foam in one cheek mean the main slope is foamed too?
Not proved. The visit opened one dormer cheek only and did not sample the foam or test the rafters still hidden on the main slope. What is in the cheek does not describe the rest of the coating. The main slope stays undecided until someone looks at it under a fresh instruction. This report has not made that look.
Can the roof covering be signed off from inside the dormer?
No. One opened cheek does not show the covering on the main slope, and the foam stops that view where it coats the rafters. The survey did not test those hidden timbers and did not sample the foam. The covering condition from the underside remains undecided. A separate roof inspection would be needed before anyone treats it as seen.