What Are the Downsides of Spray Foam Insulation?

At first glance, spray foam insulation seems like a no-brainer. It’s airtight, energy-efficient, and promises to keep your home warm all year round.

But over the last few years, a growing number of UK homeowners have run into major problems — particularly with spray foam installed in lofts and roof spaces.

If you're wondering what the catch is, this guide breaks down the most common downsides, and why so many people are now choosing to remove it.

1. Mortgage and Survey Issues

This is the big one.

Spray foam — especially closed-cell foam — makes it difficult or impossible for surveyors to inspect roof timbers. That raises red flags during:

• House sales
• Remortgages
• Equity release applications

Many lenders now either decline applications or require full removal of the foam before they'll proceed. We cover this in detail on our Spray Foam Removal page.

2. Moisture and Condensation Risks

Spray foam forms an airtight seal — which sounds good until it traps condensation in your loft. This can lead to:

• Mould and mildew
• Timber rot
• Reduced lifespan of roof components

Older roofs, in particular, were never designed to be completely sealed. They rely on passive airflow — something spray foam blocks completely.

3. Difficulty Spotting Problems

Because the foam is applied directly to the underside of the roof, it hides:

• Leaks
• Insect activity
• Damp patches
• Timber damage

In many cases, homeowners only find out there's an issue when the foam is removed — often years after it was installed.

4. Hard to Remove

Unlike traditional insulation, spray foam can’t just be pulled out.

It adheres tightly to tiles, rafters, and membranes. Removal requires:

• Careful manual labour
• Proper disposal
• A follow-up re-insulation plan

At Snug & Secure, we specialise in this kind of work — and regularly help homeowners restore breathability and structure to their lofts.

5. Unknown Installation Quality

There’s no national certification scheme or oversight for spray foam installers. As a result, quality varies wildly — and we see far too many homes with:

• Poor ventilation
• Incomplete coverage
• No paperwork or guarantees
• Foam sprayed over damp or debris

Final Thoughts

Spray foam insulation might look tidy on the surface — but beneath it, problems can brew for years.

If you're planning to sell, access equity, or just want peace of mind, removing it may be the smartest option. We offer straightforward advice and no-pressure quotes to help you move forward.

Get in touch, or explore our full blog to learn more about insulation that works — without causing future problems.