Morgan Sloane

Spray Foam Insulation

Spray Foam Insulation and why you should avoid it

Spray polyurethane foam (SPF) has been around for over 30 years. Increasingly offered as an alternative roof insulation, it tends to be a ‘quick fix’. But it’s also known for being a fire risk and can cause property damage in many instances. Here, we explain why spray foam insulation is considered ‘bad’ by many mortgage lenders (and good builders), and the damage it can do.
In theory, it sounds good. A spray foam that expands up to 60 times or more should provide excellent insulation. It is, in fact, a better insulator than mineral wool. But it’s also an expensive option that causes too many other issues.
There are two types of SPF – the spongey ‘open cell’ type and ‘closed cell’ that dries into a rigid state. They can be used in walls and floors as well as roofs and lofts. The issues arise mainly in roof spaces and in poorly ventilated conditions, where even the more spongey open cell SPF can block ventilation and exacerbate conditions, causing condensation and rotting timbers.
SPF is sprayed onto surfaces like wall cavities, roof timbers and rafters, sticking firmly. The problem with that is it can block ventilation, trapping any moisture inside the timbers. That trapped moisture can lead to rot, which you may not notice for years, making the whole roof dangerous and unrecoverable. 

The Government’s ‘Green Homes Grant’

Although the date for applications to the Green Homes Grant scheme is now closed, the Government is still keen to help homeowners create greener, carbon zero households. So further ‘green lending’ and similar grants should become available. This will enable lenders to provide lower rates for greener homes, being those with a better EPC rating. 
The worrying aspect of this, though, is that many contractors will use the one benefit of SPF (its good insulating properties), to encourage homeowners to use it and reduce their energy bills. 
This article sets out the reasons why you should never choose SPF to insulate your home. We urge you to consider the many costly issues of SPF, including: 
·         Moisture not able to fully dry out, leading to condensation and timber rot
·         Accelerates any existing issues if used in roofs and other areas already in poor repair
·         Poorly installed SPF can lead to structural safety problems
·         Many banks and mortgage providers won’t lend on properties containing foam insulation
·         It can be an issue with PVC insulated cables
·         Resale of properties with spray foam insulation can be badly affected
·         Removal of the hardened foam material is difficult and can damage the timbers, bricks and other material it was adhered to, especially where it’s penetrated crevices and gaps
·         Removal is often more expensive than installation, and the material is difficult to recycle, usually ending up in landfill 
·         As SPF is sprayed on-site, harmful fumes are released into your home during installation 
·         SPF cannot be installed as a DIY project due to its safety issues, and it cannot be decorated over 
If any dampness is found in roof spaces, we advise that you seek professional advice from a chartered surveyor, like us here at Morgan Sloane, to find out whether the damp is a condensation problem or a penetrating one.
Don’t do it! Say ‘no’ to SPF!

Mortgage lenders may find properties with SPF unmortgageable

SPF has become the Japanese Knotweed of mortgage lenders. If it’s known to be in your home, a mortgage provider may find it unmortgageable. Unless you go to the expense and upheaval of having your entire roof replaced, that is. Because getting rid of SPF once it’s in place can be exceedingly difficult, often causing even more damage.
The main reason that mortgage lenders may initially decline you is because the roof space has been sealed with SPF, which restricts air circulation, leading to condensation and wood rot, as mentioned above. This is understandably a major concern to mortgage lenders, especially when a buyer needs a minimum 20-year-term mortgage. 
Surveyors and valuers will then need to provide mortgage lenders with a discounted value. To do that, we need to request further information, such as a specialist report or a written long-term guarantee against the failure of the foam. Even then, the few mortgage lenders that will lend on properties with spray foam insulation will only usually do so if the property has open cell SPF. 
Requesting all this additional documentation can take a long time, prolonging the agony for you and your prospective purchaser as you wait for their mortgage offer. If they’re lucky enough to get it. 
Don’t ever agree to spray foam insulation!

The expense of rectifying SPF damage

Conducting remedial repairs prior to putting your house on the market will help mortgage providers agree to a valuation sooner. But of course, these repairs can take a long time.
No roof covering lasts forever. Spray foam insulation may save energy, but the cost of rectifying any damage is likely to far outweigh that energy saving. And if you need to have your entire roof replaced, as many people with SPF damage have had to, it can be an extremely expensive and stressful time while works are carried out. 
As valuers, we often find that spray foam insulation has been mis-sold to people, often by scammers and cold callers targeting the more vulnerable homeowners who can least afford to deal with the consequences. We find this particularly reprehensible. 
Some of the persuasive ways SPF is mis-sold include:
·         As a long-term (80+ years) energy saving investment
·         As a reinforcement for your roof, preventing slates and tiles from slipping
·         Protects water tanks and pipes from freezing
·         Creates a clean, dry loft space
·         May lower energy bills by up to 20%
These claims are debatable. Although SPF can be used safely in some houses if installed correctly, we advise to avoid it at all costs. 
Say ‘no’ to spray foam insulation!


SPF should never be used in older buildings

If you live in a beautiful old property, steer well clear of SPF! Spray foam insulation shouldn’t be used in heritage and thatched properties, historical buildings or properties in conservation areas.
In fact, according to Heritage House, they have seen entire roofs rotted and unrecoverable after SPF has been used. They state that by using SPF in your roof, ‘…you will devalue your home by the amount that a new roof will cost, and more.’ And we agree.
Indeed, a new roof can cost many thousands of pounds, especially for older listed properties that may need hand-made clay roof tiles to ensure it’s in keeping with the surrounding area.

Further guidance on SPF coming soon

I recently spoke with the Chairman of the RPSA, Alan Milstein, to discuss this topic. We agreed that spray foam is the Japanese Knotweed of roofs.  Milstein said that it causes many concerns and there needs to be a clearer understanding of the product.
To that end, Alan said that a stakeholder working group is being set up to include a range of experts with a mix of skill sets. Their objective is to provide clear guidance by spring or summer 2022. 
Panel members include:
  • Lenders
  • UK Finance
  • RICS
  • RPSA
  • PCA
  • English Heritage 
  • Historic Environment Scotland (Scottish Heritage)
  • Cadw (Welsh Heritage)
  • Government 
We look forward to hearing their findings. 

Never, ever agree to spray foam insulation!
If you’re concerned about SPF in your home, we will help. Get in touch to book an appointment to discuss your current situation, telephone 0800 161 5767, or email for a friendly initial chat. 

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