Spray foam and lenders
Spray foam fills a dormer cheek and the main slopes are unfoamed. What tile or slate under that cheek can no longer be seen?
The tile or slate under the foamed dormer cheek can no longer be seen from inside. Spray foam fills that cheek, and the main slopes are unfoamed, so the main slopes are a different view. The cheek covering, its fixings, and the underside of the tile or slate there are hidden by the foam. The survey has recorded foam in the cheek and clear slopes elsewhere. It has not removed the foam and has not seen the covering that the cheek conceals. That hidden face is the one this note cannot describe.
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 applied to the underside of a roof stops the surveyor seeing the materials it covers. On a dormer cheek that is a small area, but it is the whole of that cheek. Unfoamed main slopes can still be looked at from the loft, and their condition must not be copied onto the cheek or copied back the other way. The survey has not said the hidden tile or slate is sound, and it has not said it has failed. It has said it cannot be seen.
Read the cheek and the main slopes as separate. Tell the solicitor foam hides the covering under the dormer cheek and the main slopes were unfoamed. If someone needs to see that cheek covering, that is a further look the survey has not done, and it is not a licence to rip the foam out on a whim. Do not describe the unseen tile or slate as inspected. Keep any foam paperwork apart from the slopes you can still see.
What should you ask your surveyor?
- Which dormer cheek is filled with spray foam?
- What tile or slate under that cheek can you no longer see?
- Were the main slopes unfoamed, and were they a separate view?
What are the typical next steps?
- Read the foamed cheek and the unfoamed slopes as separate.
- Tell the solicitor the covering under the cheek was not seen.
- Do not describe that hidden tile or slate as inspected.
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
If the main slopes look sound, is the covering under the foamed cheek known?
No. Sound-looking main slopes are the unfoamed slopes. They do not show the tile or slate under the foamed cheek, which can no longer be seen. The survey has not transferred their condition sideways. The cheek remains concealed, and the slopes remain the part that was visible.
Did the survey lift the cheek covering, or only see foam from inside?
No. The survey did not lift tiles on the cheek. It saw spray foam from inside and could not see the covering under it. The main slopes being unfoamed does not mean the cheek was opened. The tile or slate under the cheek was not inspected.