Open Cell Spray Foam
Open cell foam is the soft, spongy type — usually white or pale cream, and much thicker than closed cell foam. It squashes under a finger and springs back. It lets some water vapour through, which is why it’s sometimes described as “breathable”, but it still covers every rafter and the underside of the roof, so a surveyor can’t see the structure.
It’s the most common type we find in Exeter lofts, particularly in installations from the last ten or fifteen years.
Removing Open Cell Foam
Because it’s soft, open cell foam usually comes away faster than rigid foam. We slice it back from the face of each rafter and lift it out of each bay in sections, then clean the timbers and underside of the felt. There’s more volume to bag up, so waste handling is a bigger part of the job than the cutting.
Where It Can Hide Problems
Open cell foam can soak up water from a leak and hold it against the timber. In older roofs with broken slates or failing ridge mortar, we sometimes find damp patches behind otherwise dry-looking foam. That’s one of the main reasons lenders want it out: what looks fine from the hatch can be different behind.
Membranes and Breathable Felt
Many newer roofs have a breathable membrane rather than old bitumen felt. Open cell foam sprayed onto a membrane can sometimes be peeled away cleanly; in other cases it has soaked into the fabric. We’ll show you in the test bay and explain whether the membrane is likely to need attention afterwards.
What it typically costs
Open cell foam in a typical Exeter family loft usually falls in the middle band. Small or partial jobs are at the lower end.
- Small or partial spray foam removalFrom £1,500 to £3,000
- Typical 3-bed loft spray foam removalAround £3,000 to £5,000
- Larger or difficult closed-cell foam removal£5,000 to £8,000+
- Per square metre guideRoughly £40 to £80+ per m²
Guide prices only. Every loft is different, so a confirmed quote usually needs an inspection or at least clear photos. A guide, not a fixed price. See how we price Exeter jobs.