Spray foam insulation was once seen as a clever fix for draughty homes and high energy bills. But over time, it's become clear that this type of insulation brings more risks than rewards — especially when used in roof spaces.
From hidden moisture and timber rot to health concerns and mortgage refusals, the hazards of spray foam are well-documented. At Countrywide Roofing and Insulation, we've helped countless homeowners across the UK safely remove spray foam from their lofts after things went wrong. In this post, we'll explain why spray foam is considered hazardous — and what to do if you already have it in your home.
1. It Traps Moisture and Damages Roof Timbers
Spray foam insulation is applied directly to the underside of the roof, sealing the loft space. While that may sound good in theory, it also traps any moisture that enters the area — which is where the real problems begin.
Closed cell spray foam is particularly problematic. It forms a rigid, airtight barrier that blocks ventilation. Even a small leak or buildup of condensation can lead to trapped moisture, which eventually seeps into the timber. Over time, that causes rot, mould growth, and in some cases, serious structural weakening.
Even open cell spray foam, which is softer and more breathable, can absorb moisture like a sponge — while hiding early signs of decay.
📊 Stat: Around 1 in 4 homes with spray foam insulation experience moisture-related issues within five years.
2. It Can Make Your Home Unmortgageable
Another major hazard is the impact on your property's value and financial flexibility. Most UK lenders and surveyors now treat spray foam as a red flag — and many will not approve mortgages or remortgages where spray foam has been applied in the loft.
The reason? Spray foam makes it nearly impossible for surveyors to inspect the condition of your roof timbers. If they can't see what's going on underneath, they won't sign off on the structure — and neither will most lenders.
This leaves many homeowners unable to sell, release equity, or refinance until the foam is completely removed.
📊 Stat: Over 70% of UK lenders now restrict or reject mortgage applications for homes with spray foam insulation.
3. Health Risks Linked to Spray Foam
Spray foam contains chemicals — particularly isocyanates — that can cause irritation to the skin, eyes, and lungs. During application, these are released into the air and can linger if the area isn't ventilated properly.
Poor installation or foam that begins to degrade over time can release unpleasant odours and harmful particles into the air. Some homeowners report respiratory problems, headaches, and persistent irritation — especially in poorly ventilated loft conversions.
While risk is highest during installation, long-term exposure can also cause concern — which is why safe and thorough spray foam removal is essential.
4. Removal Isn't Simple — But It's Often the Only Option
Once spray foam is installed, it doesn't just peel off. Especially in the case of closed cell foam, the material bonds tightly to the rafters and roof felt. Removing it requires skill, specialist tools, and care to avoid damaging the roof structure further.
That said, removal is often the only way to restore your property's value, breathability, and mortgage eligibility.
At Countrywide Roofing and Insulation, we're specialists in open cell spray foam removal and closed cell spray foam removal, and we handle each job with care — ensuring your roof is left in a safe, breathable state, ready for resale or refinancing.
Like Sealing a Wet Sponge in Plastic
Imagine taking a slightly damp sponge and sealing it in an airtight plastic bag. At first, it looks fine — but inside, the moisture festers. Mould grows, and decay sets in. That's exactly how spray foam behaves in a roof space. It seals in heat — and all the moisture and hidden problems along with it.
What Should You Do If You Have Spray Foam in Your Loft?
If you've already had spray foam installed, don't panic. But don't ignore it either. Here's how to deal with it:
1. Get a Professional Assessment
We'll inspect your loft, identify the type of spray foam used, and check for any signs of damp or rot.
2. Request a Free Removal Quote
Based on what we find, we'll give you a clear, fixed-price quote for safe removal — with no pressure and no surprises.
3. Restore Your Roof's Health
Once the foam is removed, we can re-insulate your loft with breathable, mortgage-compliant materials that won't compromise your roof structure.
FAQs: The Hazards of Spray Foam
Is spray foam insulation dangerous?
It can be. It traps moisture, can damage roof timbers, and may cause health problems if poorly installed or left to degrade.Can spray foam affect my mortgage?
Yes. Many lenders now reject homes with spray foam insulation, especially in the roof. Removal is often required before a sale or remortgage.
How long does it take to remove spray foam?
Most jobs take between 2–5 days, depending on the size of your loft and the type of foam.
Is it expensive to remove spray foam?
Costs vary, but it's often less than the potential financial impact of leaving it in place. We offer free quotes and expert advice.
Is removal disruptive?
We work quickly, cleanly, and with care — minimising disruption and leaving your loft in safe, clean condition.
Final Thoughts
Spray foam might have once seemed like a smart upgrade, but for many UK homeowners, it's proven to be a costly mistake. From health concerns to property devaluation and mortgage refusals, it's clear that spray foam brings risks that far outweigh its claimed benefits.At Countrywide Roofing and Insulation, we help homeowners safely remove spray foam and restore their roof space. Whether it's open cell or closed cell, we'll guide you through the process — and help you breathe easy again.
Worried about the impact of spray foam insulation?
Contact Countrywide Roofing and Insulation today for expert advice and a free, no-obligation removal quote.