The short answer
- The spray foam stories are mostly residential. The concerns in the UK press centre on houses, typically foam sprayed between or onto timber rafters in pitched roofs, where surveyors cannot see the timber.
- Irish banks have said spray foam is not a factor for them. In an Irish Times article on 12 September 2024, Bank of Ireland said spray foam "is not currently a factor in relation to mortgage declines", and AIB said it was not aware of any issues.
- Commercial buildings are a different case. Most have steel sheets on steel purlins, concrete or asbestos cement, not timber rafters. There the main job of the foam is to insulate and stop condensation on a cold sheet.
- Records are what matter. The product data, warranty, installer, thickness readings, photographs and fire strategy answer the questions a buyer, lender, insurer or surveyor will ask.
Where the spray foam stories come from
Most of what you read about spray foam and mortgages comes from the UK residential market. The stories follow a familiar pattern: a homeowner had foam sprayed into the loft, often to the underside of the roof between timber rafters, and later found a lender or surveyor reluctant to value the house.
The worries raised in those cases are specific to that kind of roof:
- Hidden timber. A surveyor cannot see the condition of rafters and battens once they are covered in foam.
- Moisture against timber. Poorly specified or poorly installed foam in an unventilated timber roof may trap moisture against the wood.
- Unknown products and installers. Many domestic jobs were done with no records of the product, the thickness or who installed it.
- Removal cost. If a lender asks for the foam to come out, the owner faces an unplanned bill.
Those are real concerns for a house with a timber roof and no paperwork. They do not transfer automatically to a steel-framed warehouse, a dairy unit or a concrete-roofed factory.
What Irish lenders have said on record
In September 2024 the Irish Times looked at whether Irish homeowners should avoid spray foam as UK lenders clamped down. The article carried statements from two of the main Irish banks:
- Bank of Ireland: "Spray foam is not currently a factor in relation to mortgage declines".
- AIB: AIB said it is not aware of any issues in relation to spray foam.
Two points of context matter. First, the article was about residential mortgages, not commercial lending, so it does not tell you how a commercial lender or insurer will view a particular building. Second, it is a statement from September 2024. Lending policies change, so ask your own lender, broker or insurer directly if a transaction depends on it.
We do not quote any other Irish lender, insurer or surveyor position here, because we have not seen one on the record from a primary source.
Why commercial buildings are a different case
| Typical house with loft foam | Typical commercial or agricultural building | |
|---|---|---|
| Roof structure | Timber rafters and battens | Steel purlins, steel or concrete frame |
| Roof covering | Tiles or slates on felt | Profiled metal, fibre cement, asbestos cement, concrete |
| Why foam is used | Loft insulation | Insulation, condensation control, sealing laps and gaps |
| Main risk if done badly | Moisture and decay in hidden timber | Leaks hidden under the foam; missing fire protection |
| Records usually kept | Often none | Specification, product data, warranty, photographs, readings |
General comparison. Every building is surveyed on its own merits.
On a metal roof, the problem closed-cell foam solves is a cold sheet that drips condensation. See why metal roofs drip. Steel purlins do not rot. Asbestos cement sheets are best left undrilled, and bonded foam avoids fixings through them.
Where caution is still justified
- Timber roofs in commercial buildings. Some older workshops, halls and barns do have timber. The survey checks the timber condition and ventilation before any foam is specified.
- The wrong foam. Open-cell and closed-cell foams behave very differently. Read open-cell vs closed-cell spray foam.
- Leaks under the foam. A leaking roof is repaired or coated before the underside is sprayed.
- No fire strategy. The designer confirms fire requirements under TGD B in the Republic or Technical Booklet E in Northern Ireland.
- No records. Without product, thickness and installer records, a future buyer has only your word.
Buying, selling or refinancing a building with spray foam?
Tell us what is in the roof and what records you have. We will explain what a lender or surveyor is likely to ask for.
The due-diligence file to keep
If you insulate a commercial building with spray foam, put these in the building file on handover. If you are buying one that already has foam, ask for them.
- Pre-works survey. Roof type, sheet and fixing condition, leaks, moisture readings, any asbestos, photographs.
- Specification. Product, thickness per area, the U-value it was designed to reach, any protective coating.
- Product data. The technical data sheet with declared values. Enverge Nexseal LE, for example, publishes a thermal conductivity of 0.027 W/m·K and a closed-cell content above 90% (Nexseal LE product data).
- Warranty documents. Nexseal LE carries a 25-year manufacturer-backed product warranty. Keep the certificate and any installer workmanship warranty together.
- Installer details. Who installed it and on what dates. Use an approved spray foam installer.
- Thickness readings and photographs. Before, during and after, zone by zone.
- Fire strategy record. What was required and what was applied, for example DC315 intumescent coating where specified.
- Asbestos records where relevant: survey, plan of work and permit. See asbestos regulations in Ireland.
- Energy and compliance records. The BER and any building control or assigned certifier correspondence. See TGD L 2022 insulation requirements.
Selling or refinancing? A tidy file with the specification, warranty and photographs turns "there's spray foam in the roof" from an open question into a documented upgrade.