Spray foam and lenders
Spray foam has been applied to the underside of a thatch. Why is that a product question for the lender and the thatcher, not a quilt the survey can ignore?
Because spray foam is on the underside of the thatch, it is a product question for the lender and the thatcher, not a quilt the survey can ignore. Foam bonded under thatch hides the underside and is not a quilt you lift at a corner. RICS says spray foam can restrict the view of roof timbers, and that lenders have their own questions. The survey does not set lender policy, and it does not shrug the foam off as ordinary insulation. The thatcher is the person for the thatch. The lender asks what the lender asks.
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?
A quilt can be pulled back so a surveyor can see rafters. Foam sprayed onto the underside of thatch does not pull back. The inspection then says what it could not see, which is the point rather than a nuisance to delete. Do not call it a quilt in the hope a lender will stop asking. Some lenders have been concerned about spray foam. The product and the missing view are what you pass on.
Ask the seller for the installation papers RICS points buyers towards, and ask the surveyor which parts of the thatch underside were hidden. Speak to a thatcher about the covering as a thatch, not as a foamed loft. If a lender wants answers, give them the limit of the inspection and the papers you actually hold. Do not invent a stripping cost, and do not ignore the foam because the ridge looks neat from the lane. The survey cannot see through it.
What should you ask your surveyor?
- Which parts of the thatch underside were hidden by the foam?
- Did you treat it as foam, not as a quilt you could lift?
- What papers should the lender see, without you setting their policy?
What are the typical next steps?
- Tell the lender and the thatcher there is foam under the thatch.
- Do not describe the foam as a quilt the survey ignored.
- Ask for the installation papers rather than guessing the roof is clear.
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 you are paying cash, can the foam be ignored?
No. Paying cash does not make the thatch underside visible. The foam still limits what the survey could see of the timbers above.
Does a neat thatch ridge prove the foam is fine?
No. The ridge is the outside. Foam on the underside is the product the survey could not see through, and it is not a quilt to ignore.