Spray foam insulation was at one point a highly popular insulation option across the UK, especially when use was encouraged by government grant funding schemes. However, what was once seen as an effective solution for improving energy efficiency has now become a significant concern for many homeowners.
From mortgage refusals to property devaluation, the issues surrounding spray foam insulation are causing real issues for thousands of UK households.
In this comprehensive guide, we’ll explore the key issues you need to know about spray foam insulation and what options are available if you’re affected.
What is Spray Foam Insulation?
Spray foam insulation is a liquid polymer that expands when applied to surfaces. It’s typically sprayed into roof spaces, lofts, and wall cavities where it hardens to create an insulating barrier. The material can expand up to 30 times its original size, filling gaps and cracks that traditional insulation might miss.
There are two types: open cell and closed. And there are problems with closed cell insulation and open cell.
Spray foam insulation gained significant popularity in the UK during the 2000s and 2010s. Government schemes, such as the Green Homes Grant, actively promoted its installation.
Naturally, many homeowners found promises of reduced energy bills and improved home efficiency an appealing proposition.
Open Cell vs Closed Cell Spray Foam
There are two main types of spray foam insulation, each with different properties and applications:
| Feature | Open Cell Foam | Closed Cell Foam |
| Density | Lighter and softer | Denser and rigid |
| R-Value | Lower insulation value | Higher insulation value |
| Moisture Permeability | More breathable | Creates a vapour barrier |
| Cost | Less expensive | More expensive |
| Common issues | Moisture trapping with poor ventilation | Structural stress, expansion problems |
Note: Open-cell foam is more commonly used in UK homes. It remains soft after installation and allows some air movement. Closed-cell foam creates a complete barrier but can cause structural issues if installed incorrectly. But that doesn’t mean open-cell insulation issues aren’t a thing – you should still be concerned because the following issues apply to both types of spray foam.
The Major Issues with Spray Foam Insulation
Despite its effectiveness as an insulator, spray foam insulation has created serious problems for many UK homeowners.
These issues have become so widespread that they’ve attracted significant media attention and government concern. Previously, major newspaper outlets, such as The Guardian and BBC, have talked to enraged homeowners on the matter.
Moisture and Ventilation Problems
The most significant issue with spray foam insulation is its impact on moisture control within your home. Traditional roof spaces rely on natural ventilation to prevent condensation buildup. Spray foam can disrupt this balance.
Key moisture-related problems include:
- Condensation trapping: Foam prevents natural air circulation, causing moisture to become trapped
- Timber rot risk: Persistent dampness can cause roof timbers to decay over time
- Mould growth: Poor ventilation creates ideal conditions for mould and mildew
- Structural damage: Rotting timbers can compromise your roof’s structural integrity
- Ventilation disruption: Foam blocks traditional airflow paths through the roof space
These problems are prevalent with closed-cell foam. However, even open-cell foam can cause issues if your roof lacks proper ventilation or has underlying moisture problems.
Read our guide about why moisture issues are such a problem for spray foam.
Installation and Removal Challenges
Spray foam insulation presents unique challenges both during installation and if removal becomes necessary. We’ve seen these practical difficulties catch homeowners off guard.
Installation challenges include:
- Professional requirement: DIY installation is dangerous and often ineffective
- Toxic fumes: Installation requires evacuating the property for 24-28 hours
- Rogue traders: Unqualified installers have caused widespread damage across the UK
- High costs: Professional installation typically costs £20-£50 per square metre
- Weather dependency: Installation requires specific temperature and humidity conditions
Removal is even more problematic since the foam bonds permanently to roof timbers and materials.
Additionally, removal often damages the underlying structure, and professional removal can cost thousands of pounds. Finally, some materials may need complete replacement after foam removal.
Mortgage and Property Value Problems
The mortgage market has become increasingly hostile towards properties with spray foam insulation, with many mortgage lenders rejecting spray foam properties.
This shift has caught many homeowners completely off guard. What was once a government-endorsed energy efficiency measure has become, for some, a serious barrier to selling your home, with many wondering: ‘can I sell my house with spray foam?’.
Lender Restrictions and Refusals
A BBC investigation revealed that a quarter of the UK’s biggest mortgage lenders now refuse properties with spray foam insulation.
This isn’t a small problem affecting niche lenders. Major high street banks and building societies have implemented these restrictions.
The following table shows the current positions of major UK lenders:
| Lender | Position on Spray Foam | Requirements |
| TSB Bank | Will not lend | Complete Refusal |
| Principality | Will not lend | Complete Refusal |
| Nationwide | Case-by-case basis | Extensive documentation required |
| Halifax | Cautious approach | Specialist surveys are often required |
Such lenders cite several concerns. They worry about hidden structural damage that foam might conceal – a worry shared by industry bodies like RICS who have stated their worries about spray foam insulation clearly too.
For instance, assessing the condition of roof timbers becomes nearly impossible once foam is applied. As such, the potential for costly repairs makes properties too risky for standard living.
Impact on Property Sales
The lending restrictions have created a domino effect in the property market. Buyers struggle to secure mortgages for affected properties. This severely limits your potential buyer pool when selling.
Fact: Estate agents report that some now refuse to list properties with spray foam insulation. They don’t want to waste time on unsellable properties.
Cash buyers become your primary market. However, even cash buyers often demand significant price reductions. They factor in the cost of potential foam removal and repairs.
Health and Environmental Concerns
Spray foam insulation poses several health and environmental risks. These concerns affect both installation workers and residents.
Health Risks During and After Installation
The installation process releases potentially harmful chemicals into the air. These include isocyanates, which can cause serious respiratory problems.
Workers must wear full protective equipment during application. Homeowners must also evacuate the property for at least 24 hours.
Immediate health risks include:
- Respiratory irritation: Fumes can trigger asthma attacks and breathing difficulties
- Skin and eye irritation: Direct contact causes burns and allergic reactions
- Headaches and dizziness: Chemical exposure can cause neurological symptoms
- Sensitisation: Repeated exposure may cause long-term chemical sensitivities
Heads Up: Some older spray foam products contained more dangerous chemicals. These included potential carcinogens, such as benzene and toluene.
Long-term Environmental Impact
Many spray foam products use hydrofluorocarbons as blowing agents. These chemicals have extremely high global warming potential. Plus, they can be thousands of times more harmful than carbon dioxide.
The recycling challenges are equally serious. Foam bonds permanently to building materials. Because of this, separation and recycling are nearly impossible during renovations or demolition. Most foam-contaminated materials end up in a landfill as well.
However, the industry has begun developing more sustainable alternatives. Bio-based foam options are also emerging, though they remain limited in availability.
What to Do If You Have Spray Foam Issues
If you’re dealing with spray foam insulation problems, you’re not alone. Thousands of UK homeowners face similar challenges. Despite that, there are steps you can take to address these issues and protect your property investment.
Assessment and Documentation
Your first step should be gathering all documentation related to your spray foam installation. You need to have this paperwork on hand when dealing with lenders, surveyors, or removal specialists.
Essential documents include:
- Installation certificates: Proof of professional installation and compliance
- Product warranties: Manufacturer guarantees and performance specifications
- Before and after photographs: Visual evidence of the installation process
- BBA certificates: British Board of Agrément approval documents
- Insurance-backed warranties: Extended guarantees that lenders might accept
If you’re missing documentation, contact your original installer immediately. Many companies can provide replacement certificates.
Heads Up: If your installer has ceased trading, obtaining documentation becomes much more difficult.
Maybe consider commissioning an independent specialist survey. Property Care Association (PCA) qualified surveyors can assess your installation. Their reports carry weight with lenders and provide professional opinions on any risks.
Note: These surveys typically cost £500-£800 but can resolve uncertainty about your property’s condition.
Professional Removal Solutions
When you must remove spray foam, professional help is nearly always essential. DIY removal often causes more damage than the original foam, so we advise against it. Specialist removal companies have the equipment and expertise to minimise structural damage.
If you’re struggling to sell your property or facing mortgage difficulties due to spray foam insulation, our removal partners can provide competitive, no-obligation quotes. As leading spray foam removal experts, we understand the stress involved, but we make the process as streamlined as possible.
Simply fill out our quick form, and we’ll connect you with experienced professionals who understand the complexities of spray foam removal and can help restore your property’s marketability.
That said, the removal process typically takes several days. Contractors must carefully separate foam from timbers and materials. Some structural elements may need replacement if the foam has bonded too strongly.
Either way, after removal, you’ll need to address any revealed damage. This might include timber treatment, structural repairs, or traditional insulation installation. So, factor these additional costs into your planning and budget accordingly.
Final Thoughts
Spray foam insulation issues affect thousands of UK homeowners, creating serious challenges for property sales and mortgage applications.
While the insulation can be effective when properly installed, the risks often outweigh the benefits. If you’re experiencing problems with spray foam, don’t delay in seeking professional advice.
Just remember to document your installation thoroughly and consider specialist surveys to understand your options. Acting promptly can help protect your property investment and resolve mortgage difficulties before they escalate further.
