Open cell spray foam removal, identified and priced
Open cell foam is the softer, lighter of the two types, and it is usually the quicker and cheaper of the two to remove: £35 to £55 per square metre for removal and disposal. A free inspection tells you whether yours actually needs to come out at all.
Identification
How to tell if you have open cell foam
Open cell foam is soft. Press a thumb into it and it gives, and a small piece will crumble away rather than snap. It is lighter in weight and lighter in colour than closed cell foam, usually a pale cream or yellow, and it is most often sprayed between the rafters rather than directly onto the underside of the tiles, leaving a visible ventilation gap at the eaves. If you can see daylight or feel airflow at the eaves with the foam still in place, that is a strong sign of open cell with the ventilation path still intact.
None of that is a substitute for someone actually looking. A thumb through a loft hatch tells you which type you probably have, not whether it is causing a problem.
Prices
Open cell removal cost, £35 to £55 per m²
Softer, lighter and more common. Comes away more readily, so it is cheaper per square metre. Removal and disposal only, figures below are baseline rates for England and Wales.
| Property | Treated roof area | Removal and disposal |
|---|---|---|
| Terraced house Usually the quickest job on the list. Access is the variable, not the area. | 35 to 55m² | £1,800 to £3,050 |
| Semi-detached house The most common job we quote. A standard three-bed semi sits in the middle of this band. | 55 to 80m² | £1,950 to £4,400 |
| Bungalow A large roof over a small footprint. Often an equity release case, and usually straightforward to work in. | 60 to 95m² | £2,100 to £5,250 |
| Detached house Bigger area and more complex roof shapes: hips, dormers and valleys all add time. | 80 to 120m² | £2,800 to £6,600 |
| Large detached or barn conversion Priced on survey. Scaffolding and a longer programme are usual at this size. | 120 to 200m² | £4,200 to £11,000 |
Closed cell foam runs roughly 60% higher per square metre because it bonds harder and comes off slower. The full breakdown, region adjustment and every extra are on the cost page.
Why it costs less
Why open cell is the cheaper removal job
Three things drive the difference. It is less dense, so it comes away from the timber in bigger sections rather than fragments, which is simply faster work per square metre. It is more likely to have been sprayed with a ventilation gap left at the eaves, which means it is less likely to have trapped moisture against the timbers in the first place. And it usually parts from the breather membrane or sarking felt more cleanly than closed cell foam does, which means membrane replacement, one of the biggest extras on a removal job, is less often needed.
None of that is guaranteed on every roof. A badly installed open cell job with no ventilation gap can still cause problems, and the only way to know is to look.
No obligation, no deposit
Have someone look at it properly
An hour in the loft and you will know exactly where you stand, in writing, with photographs. If the foam is sound, that is what the report says and there is nothing to pay.
Book the free inspection
Two steps. No deposit, and nothing to pay if the foam is sound.
When it can stay
Open cell foam does not automatically need removing
Of more than 500 properties inspected by the Property Care Association and the HomeOwners Alliance, 35% had a defect caused by the foam, which means around two thirds did not, May 2025. Open cell foam with a working ventilation gap and sound timbers underneath is the configuration most likely to fall into that two thirds.
If the reason removal is being discussed is a lender who cannot see the timbers rather than a lender who has seen actual damage, a specialist inspection report can sometimes do the job that removal would otherwise be asked to do. Read do I actually need it removed before you commit to anything, and see what a proper evidence pack looks like either way.
Our rules, published
What we will never do
Trading Standards has prosecuted spray foam operations in this market, including a 2024 case with 25 victims whose average age was 77. Pretending that is not happening helps nobody. These are our rules and every one of them is checkable.
- We never cold call. If someone rang you unprompted about your loft, it was not us.Trading Standards has prosecuted cold-call spray foam operations, including a 2024 case with 25 victims whose average age was 77.
- We never take a deposit. You pay when the work is done and inspected.Advice Direct Scotland has warned about deposit-taking removal firms; one reported case took £550 against a £5,500 quote.
- We will tell you if the foam can stay.The Insulation Manufacturers Association stated in February 2026 that correctly installed foam is safe and rarely needs removing.
- We never claim your home is on a national database or worthless.The Property Care Association named that claim as fabricated in August 2026. No such database exists.
- The price is written down before anything starts.It changes only if you ask for extra work, in writing.
- If the membrane is damaged, the report says so.Foam frequently bonds to and destroys the old felt. Covering that up is the failure the PCA's new removal standard is written to stop.
Open cell removal questions
How do I know if my loft has open cell or closed cell foam?
Open cell is soft, crumbles under a thumb, lighter in colour and usually sprayed between the rafters with a visible gap at the eaves. Closed cell is hard and rigid, often sprayed straight onto the underside of the tiles with no gap. A proper inspection confirms it and checks what is underneath, which a description from a loft hatch cannot.
Does open cell spray foam ever need to come out?
Yes, when the timbers underneath show decay, when there was never a ventilation gap despite the foam being open cell, or when your specific lender will not accept a report regardless of condition. It is the less common outcome for open cell, not an impossible one.
Can open cell foam be removed without damaging the membrane?
Usually yes, more often than with closed cell foam, because it tends to part from the membrane more cleanly. It is not guaranteed on every roof, and any quote should say what happens, and what it costs, if the membrane does not survive.
How long does open cell removal take?
One to two days for a terrace or small semi, two to three days for a standard three-bed semi. Add time only if timber repair or membrane replacement is needed once the foam is off.
Is open cell foam less likely to cause damp problems?
Generally yes, mainly because it is more often installed with a ventilation gap that lets moisture escape rather than trapping it against the timber. Closed cell foam sprayed with no gap is the configuration most associated with trapped moisture. Neither type is risk free if it was installed badly.
Read next
Closed cell removal
Denser, more expensive, and the job most likely to need a new membrane.
Read thisRemoval and re-insulation
Once the foam is out the loft has no insulation left at all. Quoted as one job.
Read thisDo I actually need it removed?
Around two thirds of inspected lofts had no defect at all. Find out which kind yours is.
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