Spray foam and lenders
What is the difference between spray foam under the roof and a quilt on the loft floor?
A quilt on the loft floor sits above the ceiling, between or over the joists, and leaves the rafters and the tiles visible. Spray foam under the roof is stuck to the rafters or the underlay and can hide them. Lenders’ questions are aimed at the second. A home survey should say which one is there.
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?
Both are insulation. They are not the same inspection problem. A thick quilt can hide the ceiling joists and the wiring in the loft floor. That is a different limitation from a hidden roof. The surveyor may need to note both if both are present. Do not let “the loft is insulated” blur them.
Energy Saving Trust material about ordinary insulation is not a comment on spray foam. Do not quote a cavity-wall cost as a foam removal cost. Removal of roof foam, if it happens, is a roofing job with a price for this roof. A deeper quilt, if you simply want more insulation on the floor, is a normal loft job and still must not block the eaves ventilation.
What should you ask your surveyor?
- Which insulation did you see: a quilt, foam on the rafters, or both?
- What is hidden by each?
- Is eaves ventilation blocked by the quilt?
What are the typical next steps?
- Describe the two products separately to the lender.
- Do not strip a sound quilt because of a spray-foam headline.
- If foam is on the rafters, follow the spray-foam questions. If it is only a quilt, say so and stop.
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
Can a quilt cause condensation?
If it blocks the eaves, moisture can build up in a cold roof. The surveyor should mention blocked vents if they saw them. That is a ventilation defect, not a lender foam ban.
Is multifoil the same as spray foam?
No. Multifoil is a sheet product. Name what is actually fixed to the roof. The surveyor should do the same.