Buying a House with Spray Foam Insulation in Cornwall

Spray foam insulation has been widely installed in Cornwall over the past two decades, particularly in loft spaces. It was often marketed as a quick fix for energy efficiency or roof consolidation. Unfortunately, it has now become one of the most problematic features you can inherit when buying a property.

Open Cell vs Closed Cell Foam

Not all spray foam is the same.

• Open-cell foam is softer and lighter. It can often be removed without damaging the felt beneath, provided the roof is otherwise in reasonable condition. Removal projects usually cost between £2,500 and £8,000, depending on the roof size, complexity, and condition.

• Closed-cell foam is dense and rigid. It was frequently applied to roofs that were already failing, in an attempt to consolidate the structure. In most cases, removal of closed-cell foam is not possible without a complete re-roof. Buyers should assume that a new roof will be required where closed-cell spray foam is present.

Installation Standards

Another issue is that spray foam insulation has often been installed incorrectly, with little regard for British Standards or ventilation requirements. In many cases installers applied foam directly to the underside of roof coverings without allowing for airflow or inspection access. This has left roofs vulnerable to hidden decay, trapped condensation, and premature failure.

Mortgage Implications

Perhaps the most serious issue with spray foam insulation is its impact on lending. In practice, most mortgage providers will not lend on properties with spray foam present, regardless of whether it is open- or closed-cell. This effectively makes the property unmortgageable until the insulation has been removed and the roof fabric assessed.

Advice for Buyers

If you are buying with cash, caution is still advised. Personally, it would be wise to not purchase a property with spray foam insulation unless the full cost of a re-roof had been deducted from the asking price. Even with open-cell foam, it is always better for the current owner to arrange removal before completion. This ensures that any hidden roof defects uncovered during the process remain their responsibility, not yours.

Taking on the problem yourself can mean significant additional expense further down the line.

Conclusion

Spray foam insulation is now recognised as a major obstacle in the Cornish housing market. Removal is often essential before a sale can proceed, and in many cases a full re-roof will be required. If you are considering buying a property with spray foam insulation, make sure you obtain specialist advice and factor the potential costs into your negotiations.