Open Cell and Closed Cell Spray Foam Removal: Getting the Right Foam Out Properly

Not all spray foam comes out the same way, and not all spray foam should be removed by the same method. That’s the bit most homeowners aren’t told when they start ringing round for quotes.

This page covers the practical differences between removing open cell and closed cell spray foam from a Leeds loft — how each one behaves, what tools and time each one takes, and what it costs. If you’ve landed here because a RICS surveyor flagged foam in your roof, or a mortgage valuation came back with a condition attached, you may want to start with our main Spray Foam Removal Leeds page first, which covers the mortgage and survey side in more depth. This page goes deeper into the technical removal work itself.

We’re based at Unit 9, Admiral’s Yard, Low Road, Hunslet — a proper Leeds unit, not a call centre routing you to whoever’s nearest. Every job starts with a free, no-obligation survey and a written quote.

How to Tell Which Foam You Have

Open cell and closed cell foam look similar from the loft hatch, but they behave very differently once you try to remove them. Open cell foam is soft, spongy, and pale yellow — you can usually push a thumb into it and leave a dent. It’s lightweight and was often applied more thickly, sometimes 200mm or more, because it’s a less effective insulator per millimetre than closed cell.

Closed cell foam is rigid, dense, and typically a darker cream or off-white colour. It doesn’t compress under thumb pressure and it’s usually applied in a much thinner layer — 50mm to 75mm is common — because it insulates more efficiently and also adds structural stiffness to the roof timbers, which is part of the mortgage problem.

If you’re not sure which you’ve got, don’t guess based on a previous installer’s paperwork — foam types get misdescribed surprisingly often. During our free survey we identify the type on site, check adhesion to the timber, and note this clearly in the written report you’ll need for your lender or buyer.

Removing Open Cell Foam

Open cell removal is generally the more straightforward of the two jobs. The foam’s soft, cellular structure means it tends to peel and break away from timber in sheets or chunks rather than fusing permanently to the wood grain. Most of it can be stripped by hand using scrapers and specialist tools, working section by section across the rafters and sarking board.

This suits lofts where the foam was sprayed directly onto the roof felt or timber without excessive overspray into eaves or hard-to-reach corners. Because it comes away more cleanly, there’s usually less risk of timber damage, and dust and debris levels — while still requiring full extraction and PPE — tend to be lower than with closed cell.

Homeowners with open cell foam typically see this job completed faster and at a lower cost, simply because the material cooperates. That said, “easier” doesn’t mean “quick” — a typical semi-detached loft with open cell foam still takes a full day’s work to clear properly, vacuum the residue, and leave timbers ready for inspection.

Removing Closed Cell Foam

Closed cell is a different job entirely. It bonds tightly to timber and forms a rigid, almost plastic-like shell once cured. It won’t peel away in sheets — it has to be mechanically cut and chiselled off the timber in smaller sections, often using oscillating tools, scrapers, and in some cases controlled abrasion to lift the final residue without gouging the wood underneath.

This is slower, physically harder work, and it demands more care. Rafters and sarking boards are softwood, and closed cell foam’s grip on the surface means an inexperienced operator can easily tear timber fibres away with the foam, leaving a rougher surface than what you started with. We work section by section, checking timber condition as we go, rather than forcing large sections off at speed.

Closed cell removal suits any loft where the foam has been sprayed directly to the underside of the roof and has fully cured — which is most installations from the last fifteen years. It’s the more common scenario we’re called out to across Leeds, and it’s the one that takes longest to quote accurately, because coverage and thickness vary so much between installers.

Why Closed Cell Costs More

Three things drive the price difference. First, time — closed cell simply takes longer to remove per square metre because of the mechanical cutting involved, sometimes double the labour hours of an equivalent open cell job. Second, tooling — closed cell requires more specialist blades and abrasive equipment, which wear down faster against the denser material and need replacing more often. Third, timber risk management — because closed cell bonds so aggressively, more time goes into working carefully around joints, nail heads, and roof felt without causing damage that then needs separate repair.

There’s also a disposal factor. Closed cell foam is denser by volume, so a loft of the same size generates heavier waste loads, which affects skip and tipping costs. None of this is a mark-up — it reflects the genuine extra labour and material cost of doing the job without wrecking your roof structure in the process. We’ll confirm which type you have and price accordingly at the survey stage, in writing, before any work starts.

Who Needs This Service

This work is for homeowners facing a mortgage valuation or RICS Level 2/3 survey that’s flagged spray foam as a concern, for anyone selling a property where a buyer’s surveyor has raised it, and for landlords whose EPC assessment or lender is asking questions about roof timber access and ventilation. It’s also for homeowners who’ve simply had cold, damp, or musty-smelling lofts since foam was installed and want it properly assessed and, where needed, taken out.

Step by Step: How the Job Runs

1. Free survey — we inspect the loft, identify open or closed cell foam, check timber condition, and assess extent of coverage.
2. Written quote — a fixed price based on foam type, roof area, and access, with no obligation to proceed.
3. Protection and containment — loft space, hatch, and surrounding areas are sheeted and sealed before any tools come out.
4. Removal — foam is stripped by hand (open cell) or mechanically cut away (closed cell), section by section.
5. Timber inspection — rafters and sarking boards are checked for damage, rot, or moisture once cleared.
6. Clearance, vacuum and certification — all debris is removed, the loft is vacuumed, and you receive a written completion certificate for your lender, buyer, or records.

What You Gain

A cleared loft passes RICS scrutiny and satisfies most mortgage lenders’ conditions outright. Timber becomes visible again for damp and rot inspection — something insurers and surveyors both want to see. Ventilation is restored, which reduces the condensation risk that trapped foam can cause against roof felt. And if you’re re-insulating afterwards with mineral wool or a BBA-approved system, you get a fresh, compliant install rather than a repair over old foam. For sellers, it removes a sticking point from the transaction rather than leaving it to be negotiated off the asking price.

Cost and Timescale

Open cell removal typically runs from £45 to £65 per square metre. Closed cell runs higher, generally £65 to £90 per square metre, reflecting the extra labour and tooling described above. A standard semi-detached loft (35–45m²) usually takes one to two days for open cell, and two to four days for closed cell. Larger detached properties or heavily-coated roofs can take longer — we’ll give you a realistic timeline at survey stage, not a guess.

The free survey includes a visual inspection, foam type identification, a moisture check on visible timber, and a written quote itemising labour, disposal, and certification. There’s no charge and no obligation to book the work.

Book Your Free Survey

If you’ve got spray foam in the loft and you’re not sure whether it needs to come out, the honest answer starts with a proper look, not a quote over the phone. We’ll tell you plainly if removal isn’t necessary. Call 0113 365 1084, open 9am to 7pm, seven days a week, or book a free survey online — we cover Leeds and West Yorkshire, work is backed by BBA-approved products with a 25 year guarantee where re-insulation follows, and there’s no obligation to proceed.

Book a Free Survey