The nature of spray foam can make it tricky for valuers acting on behalf of lenders to inspect the condition of roof timbers.
When the BBC contacted the 20 largest lenders in the UK, external, five of them, TSB Bank, Skipton Building Society, Co-operative Bank, Principality and equity release lender Aviva – said they did not lend against properties where spray foam is found in the roof space.
The Yorkshire Building Society and Metro Bank said they would not usually lend where there is a significant amount of spray foam.
Equity release provider More 2 Life told the BBC it will only lend on properties with spray foam where it was fitted as part of an authorised new build and has the necessary documentation.
Other lenders such as Lloyds, Nationwide, Barclays, the NatWest Group and Santander have said they consider applications on a case-by-case basis, and will take a valuer’s report into account.
They may, however, ask homeowners for documentation showing it has been installed correctly or for a specialist report to be carried out.
In 2023, the PCA published an inspection protocol in a bid to help surveyors and lenders assess any potential risk in pitched roofs.