How Long Does Spray Foam Insulation Last?

Spray foam insulation is often marketed as a “fit and forget” upgrade — something you install once and never have to worry about again. But is it really permanent? And how long does it actually last in a UK home?

In this post, we look at the real lifespan of spray foam insulation, what can shorten it, and why more people are choosing to remove it long before it ever "fails."

Manufacturer Claims vs. Real-World Results

Most manufacturers will say that spray foam lasts 25 to 80 years, depending on the type. Closed-cell foam in particular is extremely durable — in theory.

But in reality, its lifespan is affected by:

• The quality of installation
• Ventilation and airflow in the roof
• Moisture levels behind the foam
• Structural movement or settling

We regularly remove spray foam that’s less than 10 years old — not because it’s physically failed, but because it’s causing issues elsewhere in the home.

What Usually Goes Wrong?

Spray foam itself may not break down quickly, but problems often appear around it. These include:

• Condensation and damp behind the foam
• Rotting roof timbers hidden from view
• Surveyors refusing to sign off mortgage reports
• Insurers rejecting claims due to non-breathable systems

In other words, the foam might still be intact — but it’s the impact on your home that shortens its useful life.

Can It Be Left In Place?

If your loft is dry, well-ventilated, and you’re not planning to sell or remortgage — some homeowners leave it in. But most people run into one of the following:

• A blocked sale
• A failed survey
• A lender or buyer who demands removal

That’s why we always say: just because it’s still there doesn’t mean it’s working in your favour.

What’s the Alternative?

When spray foam is removed, it can be replaced with:

• Mineral wool or fibreglass loft roll
• Multifoil insulation
• Natural, breathable options like sheep’s wool

These options may not last 80 years on paper — but they don’t come with survey red flags, and they let your roof breathe properly, avoiding future damp and structural concerns.

You can read more about that process here.

Final Thoughts

Spray foam might be sold as permanent — but that doesn't mean it's problem-free. In the real world, its “lifetime” can be cut short by survey issues, moisture problems, or simple lack of documentation.

If you're unsure whether to keep it or take it out, get in touch for a no-pressure quote — or explore more advice in our blog.