How Do I Know If I Have Spray Foam Insulation? A Homeowner’s Guide

If you’re not sure whether your property has spray foam insulation, there are several clear signs you can check yourself before booking a professional inspection.

Check Your Loft First

Head into the loft and look up rather than down. Standard mineral wool or fibreglass insulation lies flat between or over the joists on the loft floor. Spray foam is different: it is usually sprayed directly onto the underside of the roof rafters and sarking felt, so it forms a solid layer that follows the shape of the roof itself rather than sitting on the floor.

What Spray Foam Insulation Looks and Feels Like

Two main types are used in UK properties, and they look and feel quite different from each other.

• Open-cell foam: soft, spongy and slightly yellow or off-white, similar to a sponge and easy to press a finger into.
• Closed-cell foam: hard, rigid and dense once cured, often pale yellow, grey or white, and does not compress when you press it.

Other Signs You May Have Spray Foam Insulation

• Your EPC certificate or a previous survey mentions an insulated or upgraded roof, without visible loft insulation on the floor.
• Roof timbers, felt or the underside of tiles are partially or fully covered rather than exposed and visible.
• A previous owner, estate agent or paperwork mentioned eco upgrades, a green retrofit, or grant-funded insulation work.
• You struggle to see the original felt or roof structure when looking up into the loft space.

Why It Matters If You Find Spray Foam Insulation

Identifying spray foam early matters because it directly affects your ability to get a mortgage, remortgage or sell your property. Many UK lenders, including Halifax, Nationwide, TSB, NatWest and Santander, will decline or delay applications on properties with spray foam until a specialist evidence report or removal has taken place. Finding out early gives you time to plan, rather than discovering it during a sale or remortgage when a survey is already underway.

What To Do Next

If you think you have spray foam insulation, the next step is a professional inspection to confirm the type, extent and condition of the foam, and whether it is affecting ventilation or the timbers underneath. This will also tell you whether removal is necessary, or whether the situation can be managed with documentation and improved ventilation.

Get Free, Independent Spray Foam Advice

The National Spray Foam Advisory provides free, independent guidance to UK homeowners who think they may have spray foam insulation, and can connect you with vetted specialists for an inspection or removal quote. Get in touch to discuss your situation.

Worried about spray foam problems in your home? Call us free on 0800 494 7163 or leave a message about your situation and we will give you the advice you need to resolve it — and a full understanding of the guidance around spray foam and how it applies to your home. We are a free, independent advisory service and we carry out no removals ourselves.

Related guidance

• what loft spray foam removal actually costs — and how to compare quotes — 2026 price ranges by property size, foam type and roof access.
• compare quotes from vetted loft spray foam removal companies — Free, no obligation, and your details go to nobody until you choose.