Beware Spray Foam Insulation

It is estimated as many as 250,000 homes in the UK have this type of insulation, with much of it installed under the Green Homes Grant scheme. Some mortgage firms are reluctant to deal with homes with spray foam insulation due to concerns over poor fitting leaving moisture trapped and roof timbers at risk of decay. 

 

Spray foam insulation has been used to stop heat escaping from roofs, lofts and attics for decades and comes in two forms and the Insulation Manufacturers Association insists that spray foam can be beneficial if properly installed. 

Closed cell spray foam is rigid once set. It is a better thermal insulator and was previously sold to stabilise failing roofs. But if it has been used inappropriately or installed poorly, it might put stress on timbers, restrict air circulation and put them at risk of decaying. 

 

Open cell spray foam remains soft once set and is only used for insulation. It is more breathable but is often installed where a highly-resistant underlay like bitumen felt is already present, stopping vapour from escaping. 

A recent survey by the BBC of the 20 largest lenders in the UK revealed 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 whilst 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. 

“We were blissfully unaware of any issues to do with it until we put the house on the market,” said one family who struggled to sell their late father’s home because of it and ended up paying thousands to have the insulation removed.