Both types are sprayed onto the underside of the roof, but they behave very differently once you try to take them off. Identifying which you have is the first step to a realistic cost.
On this page
- Open-cell foam
- Closed-cell foam
- What removal involves
- Realistic expectations
Open-cell foam
- Soft, spongy and light — it gives when pressed
- Vapour-open, so moisture can pass through it
- Removes more readily, though it still leaves residue on timbers
- Removal charged at £45/m²
Closed-cell foam
- Dense and rigid — it does not compress under thumb pressure
- Effectively a vapour barrier against the roof covering
- Bonds hard to timbers and felt, making removal slow and labour-intensive
- Removal charged at £65/m²
What removal involves
Foam is cut back and stripped from rafters and membrane, timbers are scraped back as far as practical, waste is bagged and removed, and the loft is left clear for reinsulation. Where timbers show fungal growth, anti-fungal treatment is applied before new insulation goes in.
Realistic expectations
Complete removal down to bare, pristine timber is rarely achievable — residual staining is normal. The aim is timbers that can be inspected and a roof that can breathe again.
Common questions
How do I know if my spray foam is open or closed cell?
Press it. Open-cell foam is soft and spongy; closed-cell foam is rigid and does not give. Photographs are usually enough for us to identify it remotely.
If you would like an honest opinion on your own loft, send us your postcode and a few photographs. Most lofts can be assessed and quoted remotely using satellite imagery, and we will tell you if work is not necessary.
Related: Spray foam removal • Price list • Project planner • Contact