Risk of using spray foam insulation as homeowners struggle to sell properties
Britons are struggling to sell their homes after investing in the insulation, despite many fittings being funded by the previous government's Green Homes Grant Scheme.
A quarter of the UK's 20 biggest mortgage providers said they do not lend against properties where spray foam is found in the roof space.
Others also have conditions on whether they will accept mortgage applications.
There is concern spray foam insulation can leave moisture trapped if not fitted properly, which could cause roof timbers to rot.
The Insulation Manufacturers Association estimates more than 250,000 properties in the UK have been treated with polyurethane spray foam (SPF), and it has been used in the UK for more than 30 years.
The Green Homes Grant Scheme provided grants of up to £5,000 to homeowners and landlords to make energy efficiency improvements to homes.
In the scheme, that ran until 2021, the Government paid up to two thirds of the total cost of the improvements, or 100% for people on certain benefits.
The grant could be used for insulation to a solid wall, cavity wall, under-floor, loft, roof or park home. Heat pumps, solar thermal and biomass boilers were also covered.
However, TSB Bank, Skipton Building Society, Co-operative Bank, Principality and equity release lender Aviva told the BBC they did not offer mortgages on homes with spray foam in the roof.
The Yorkshire Building Society and Metro Bank said they do not usually lend if there is a significant amount of spray foam.
More 2 Life, an equity release provider, said it will lend to properties with spray foam but only if it was fitted as part of an authorised new build and there is necessary documentation to prove it.
Lloyds, Nationwide, Barclays, the NatWest Group and Santander told the BBC it decides applications on their merit, taking a valuer's report into consideration and often wanting to see documents proving it has been installed correctly.
HSBC says it may lend if a specialist report confirms the insulation has been installed and there is a warranty, according to the Homeowners Alliance.
What is spray foam insulation?
Spray foam insulation comes in two forms - closed or open cell. It can be used in walls and roofs of homes.
Closed cell spray foam roof insulation: This is rigid and solid when it sets and has been used in the past to glue old roofs in bad condition so they last longer.
If this type of foam is used to insulate a roof then it can put stress on roof timber and restrict air circulation which can cause condensation leading to rot.
Open cell spray foam roof insulation: This is specifically designed for insulation and sets soft.
The Homeowners Alliance says: "It needs to be carefully applied by a manufacturer-approved installer. In April 2024, the Health & Safety Executive published a report demonstrating the situations where there might be a high risk of condensation and potential timber decay from applying this type of spray foam directly to the roof tiles. It also highlighted other situations that were regarded as adequate when installed correctly."
'No reason for lenders to block finance'
The Insulation Manufacturers Association says spray foam can be beneficial if properly installed, and has a code of practice for installers which includes condensation risk analysis.
It now worries homeowners could needlessly remove well-installed foam and fall victim to cowboy removal companies.
On its website, the IMA says: "If an installation has been done correctly with all accompanying pre-installation checks and post installation documents, there should be no reason for the lender not to provide the necessary finance."
It added: "There has been a lot of mis-information recently about spray foam, with some homeowners being advised to remove spray foam in order to sell their property. This has given rise to unscrupulous traders gaining information about where spray foam has been installed and targeting the homeowner to have it removed at significant cost.
"The number of cases with a genuine reason to remove the spray foam is extremely small and in most cases where removal was carried out, no problems were identified, the roof was in good condition with no rot or additional moisture detected and the spray foam application had been correctly installed. Therefore, there was no technical or performance reason to remove the spray foam."
If a homeowner is approached by a spray foam removal company the IMA urges them to think about:
- If they have an ulterior motive,
- What are the company's credentials,
- Is the business on Companies House,
- Has it changed its name and had different trading activities, and,
- Are they making false claims about the Government's grants or schemes?
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