Key facts
- Open-cell foam: A lightweight, spongy insulation material with broken cell walls that allows air and moisture to pass through.
- Closed-cell foam: A dense, rigid insulation material with sealed cells that acts as a strong barrier against water and air.
- R-value: A measure of thermal resistance; closed-cell foam typically offers a higher R-value per inch than open-cell foam.
- EBR-01: The UK's independent Code of Conduct and industry-standard framework for the professional removal of spray foam insulation.
- Removal impact: Closed-cell foam is generally more difficult and costly to remove due to its high density and strong bond to structural timbers.
What is the difference between open-cell and closed-cell spray foam insulation?
Open-cell spray foam is manufactured with intentionally broken cell walls. Once cured, it remains soft and flexible, with a sponge-like texture. It allows water vapour and air to pass through, which means moisture can accumulate within the material and in adjacent roof timbers if ventilation is inadequate.
Closed-cell spray foam is manufactured with fully sealed cells. It cures to a hard, rigid state and acts as a barrier to both air and liquid water. Its density means it bonds extremely firmly to the surfaces it contacts, including roof rafters, sarking boards, and felt underlays.
Both types have been installed in UK residential properties, predominantly in loft spaces, since the early 2000s. Both types present challenges when a property is sold or remortgaged, because many mortgage lenders treat the presence of spray foam insulation as a material consideration requiring professional assessment or removal.
Frequently asked questions
Does my mortgage lender require spray foam removal?
Many UK mortgage lenders, following guidance from RICS, will decline to lend or will impose a retention until spray foam insulation is professionally removed and the roof structure is verified as sound. Requirements vary between lenders. A report produced under the EBR-01 Code of Conduct can provide the documentation lenders and surveyors need to proceed with a transaction.
How can I tell if I have open or closed cell spray foam?
Press the foam gently with your finger. Open-cell foam compresses easily and feels spongy. Closed-cell foam is rigid and will not compress. Closed-cell foam also tends to have a smoother, harder surface. If you are uncertain, an EBR-01 registered contractor can inspect and identify the foam type as part of a professional assessment.
Is it more expensive to remove closed cell spray foam?
Industry data indicates that closed-cell foam removal is generally more costly than open-cell removal. Its rigid structure and strong adhesion to timber means mechanical removal is more labour-intensive and carries a higher risk of timber damage. In some cases, affected rafters or sarking boards require replacement following removal, adding further cost.
What is the EBR-01 standard for spray foam removal?
EBR-01 is the UK's independent Code of Conduct for spray foam insulation removal. It sets out minimum standards for assessment, removal methodology, timber inspection, and post-removal verification. Contractors registered under EBR-01 are required to follow these standards and issue compliant documentation upon completion of work.
Does spray foam insulation cause timber rot?
Open-cell foam is particularly associated with timber decay risk. Because it is permeable, moisture can become trapped against roof timbers, creating conditions that promote fungal rot. Closed-cell foam can also trap pre-existing moisture or condensation beneath its surface. Any spray foam installation that prevents adequate inspection of roof timbers is treated with caution by RICS surveyors.
How do I find an EBR-01 certified removal contractor?
The EBR-01 directory lists contractors who are registered under the Code of Conduct and have demonstrated compliance with its standards. You should only commission removal work from a registered contractor if you require documentation that will be accepted by mortgage lenders and RICS surveyors. The directory is available at ebr-01.co.uk/directory.
Can I sell my house with spray foam insulation in the loft?
You can market a property with spray foam insulation present, but buyers relying on mortgage finance may encounter lender restrictions. Many buyers' solicitors and surveyors will flag spray foam as a risk factor. Removal prior to sale, supported by EBR-01 compliant documentation, is the most straightforward way to resolve this issue and avoid delays or aborted transactions.
How EBR-01 documentation supports mortgage and surveyor requirements
When spray foam insulation is removed by an EBR-01 registered contractor, the completed work is verified against the Code of Conduct's technical standards. The contractor issues a post-removal report that records the foam type identified, the removal methodology used, the condition of exposed timbers, and confirmation that the roof structure has been inspected.
This documentation is structured to meet the information requirements of UK mortgage lenders and RICS-accredited surveyors. Where a surveyor has flagged spray foam as a risk in a valuation report, an EBR-01 compliant removal report provides the evidence needed to demonstrate that the risk has been professionally addressed and the property is suitable security for lending.
Without documentation produced to a recognised standard, vendors and buyers have no reliable means of demonstrating to a lender that removal has been carried out competently. EBR-01 fills this gap as the only independent Code of Conduct operating in this sector in the UK.
Find a registered removal contractor
If you have spray foam insulation in your property and need professional removal that meets mortgage lender and surveyor requirements, use the EBR-01 contractor directory to find a registered specialist in your area.
Find an EBR-01 registered contractor at ebr-01.co.uk/directory