Understanding Closed Cell Spray Foam Insulation
Spray foam insulation has been widely promoted across the UK for years as a quick solution to draughty lofts and high heating bills. At first glance, it looks like a smart upgrade: airtight insulation, warmer rooms, and what many installers claimed was a stronger roof.
But the reality is more complicated. Spray foam comes in two very different forms — open cell and closed cell.
Open cell spray foam → soft, flexible, sponge-like, and allows some airflow.
Closed cell spray foam → dense, rigid, rock-hard, and bonds directly to tiles and rafters.
It’s this closed cell spray foam that has caused serious problems for UK homeowners. Once applied, it forms a rigid barrier that traps moisture, prevents ventilation, and hides structural issues from view.
When a surveyor inspects a property with closed cell spray foam, they can’t properly see or test the roof timbers. For mortgage lenders and equity release providers, that’s a major red flag. In many cases, applications are refused outright until the foam is completely removed.
This makes closed cell spray foam a property value problem, not just an insulation one.
Closed Cell vs Open Cell: Why It Matters
Not all spray foam is equal, and lenders know the difference.
Open Cell Foam → Easier to remove, still a problem but less damaging.
Closed Cell Foam → Hard, brittle, and almost glued to tiles and rafters.
Removal Difficulty → Open cell can be fiddly. Closed cell requires careful, manual, tile-safe removal by trained specialists.
This is why closed cell foam is viewed so negatively. It’s not just awkward — it’s risky, and it takes skill to remove without destroying your roof.
The Consequences of Having Closed Cell Spray Foam
Homeowners often discover they have closed cell foam when it’s too late — usually during a sale, remortgage, or equity release application. That’s when the problems start:
Mortgage refusals → Many lenders won’t approve loans until the foam is removed.
Equity release blocked → Funds cannot be released with spray foam in place.
Surveyor red flags → Inspectors can’t give your roof a clean bill of health.
Hidden damage → Moisture trapped beneath the foam can lead to timber rot and mould.
Until it’s removed, your home may be effectively unsellable.
The Risks of Improper Removal
Removing closed cell spray foam isn’t straightforward. It clings tightly to tile backs, rafters, and felt. Trying to prise it off without the right methods risks major damage.
Tile Damage
Closed cell foam bonds directly to tiles. If it’s hacked or chipped away, tiles often crack or slip out of place. One cracked tile can cause a leak; several may mean costly repairs or a full roof replacement.
Hidden Damp Problems
Closed cell foam often masks existing damp or rot. An inexperienced contractor may miss the warning signs or even make them worse. Specialists know how to identify and document structural issues during removal.
Surveyor Rejection
Even if the foam is gone, lenders won’t approve your property unless the removal is documented with a proper certificate. Poor workmanship or missing paperwork means your mortgage can still be refused.
Cowboy Methods to Avoid
Unfortunately, the spray foam removal industry is unregulated. That means some contractors push methods that sound impressive but are risky, invasive, or completely unnecessary.
❌ Dry Ice Blasting
Dry ice blasting is often marketed as a modern, “chemical-free” way to strip spray foam. In reality, it’s highly invasive and dangerous:
The force can crack tiles, rip underlay, and splinter rafters.
It creates condensation and debris inside your loft.
It produces uncontrolled results that surveyors won’t accept.
It might look good in a demo video, but in practice, dry ice blasting risks leaving your roof in worse condition — with no lender-approved certificate at the end.
❌ Full Re-Roofing
Another common cowboy tactic is claiming you need a full re-roof. Unless your roof is already beyond repair, this is unnecessary.
Why do contractors suggest it? Because it massively increases their margins. A re-roof costs tens of thousands of pounds, compared with safe removal at a fraction of the cost.
Lenders don’t ask for a new roof. They ask for foam removal with certification. Re-roofing is usually just an expensive upsell.
Why Specialists Are Essential
A true closed cell spray foam removal specialist doesn’t rely on gimmicks or scare tactics. They use skilled, manual techniques that protect your tiles, leave a clean finish, and provide full documentation.
Manual, Tile-Safe Removal
Specialists use hand tools to carefully separate foam from tiles and rafters. They work section by section, protecting valleys, gutters, and eaves. It’s painstaking work, but it avoids costly damage.
Clean Finish for Surveyors
Surveyors must be able to see every part of your roof. Specialists ensure a smooth, residue-free finish, making inspections straightforward and compliant.
Lender-Approved Documentation
At the end of the process, a professional will provide:
Before-and-after photos of all areas.
Notes on rafters, underlay, and ventilation.
A Spray Foam Removal Certificate accepted by lenders.
Without this paperwork, you’re still at risk of mortgage rejection — even if the foam is technically gone.
The Professional Removal Process: What to Expect
When you hire a trusted specialist, the process is structured and transparent:
Initial Inspection → Roof checked for damp, rot, and damage.
Careful Manual Removal → Foam scraped off in small, controlled sections.
Clean Finish → Surfaces smoothed, rafters and tiles left visible.
Documentation Pack → Photos, notes, and your Spray Foam Removal Certificate.
This process ensures your roof is safe and your property is lender-compliant.
How Much Does Closed Cell Spray Foam Removal Cost?
The cost depends on loft size, accessibility, and the amount of foam.
Smaller lofts → £3,000–£4,000
Medium homes → £4,500–£6,000
Large or complex roofs → £6,000–£7,000+
While not cheap, removal usually unlocks your home’s full market value. A property blocked from selling or remortgaging may lose tens of thousands in value — far more than the cost of proper removal.
The Cost of Doing Nothing
Ignoring closed cell foam only delays the inevitable:
Failed sales and lost buyers.
Refused mortgages and blocked equity release.
Worsening damp and structural problems.
For most homeowners, removal pays for itself by restoring financial flexibility and protecting property value.
Avoid Rogue Contractors, Choose Trusted Specialists
Closed cell spray foam removal isn’t something you can risk with just any builder or roofer. The wrong choice — whether it’s dry ice blasting, a pushy re-roof, or a cheap shortcut — can leave you with a damaged roof, wasted money, and still no certificate for your lender.
The only safe way forward is manual, tile-safe removal by trusted specialists — and that’s exactly what we connect you with at National Spray Foam Advice.
We don’t carry out removals ourselves. Instead, we put you in touch with vetted, lender-approved companies across the UK who:
Use safe, compliant methods.
Protect your tiles and rafters.
Provide full documentation, including the Spray Foam Removal Certificate.
That’s how you avoid cowboys, scams, and rogue operators — by choosing experts who do the job right the first time.
