Spray foam insulation has gained popularity in the UK as a quick solution to energy efficiency. It’s highly effective for cold walls of roof spaces, so much so that, on the surface, installing spray foam insulation seems like a no-brainer.
Yet, the reality is that many people fail to consider the potential moisture issues.
Is spray foam insulation waterproof, and should you be using it in the UK? Understanding the pros and cons of spray foam could help you avoid potential problems in your home!
What Is Spray Foam?
Spray foam is a type of insulation made from liquid polyurethane. Essentially, installers apply this foam on surfaces using a spray gun to form an insulating layer.
As the spray foam sets, it expands and fills crevices. The foam then hardens to create an air-tight seal that reduces heat loss.
Spray foam is convenient because it’s easier to install than traditional insulation materials. You can even use it for floors, walls, and roofs. That said, spray foam may not be ideal for places with high humidity, and there are many other reasons to remove spray foam insulation.
The Two Types of Spray Foam
Spray foam can come in these forms.
1. Closed-Cell Foam
Closed-cell spray foam is an effective insulation material due to its ability to trap air pockets. It’s relatively solid and can sometimes support failing structures.
However, closed-cell foam isn’t vapour permeable. This means that moisture in the air can’t travel through the foam, and it may restrict air circulation.
Because of this, using closed-cell foam isn’t suitable for high-humidity areas and it certainly affects closed-cell foam waterproofing and can lead to it’s removal becoming a necessity.
2. Open-Cell Foam
On the other hand, open-cell foam is more flexible and vapour-permeable.
The problem is that open-cell foam isn’t as effective for insulation. You may need to apply a thicker layer to get the same insulating effects as closed-cell foam.
Moreover, some installers install open-cell foam on moisture-resistant underlays. Ultimately, doing so also stops vapour from escaping.
Is Spray Foam Insulation Waterproof?
No. Spray foam insulation isn’t waterproof and there are many spray foam issues caused by water absorption.
While some spray foams resist moisture penetration, it doesn’t make your home waterproof. Moreover, spray foam can’t protect your structures from dampness.
In fact, spray foam can make matters worse by trapping existing moisture in walls or roofs.
The UK experiences high levels of rainfall and temperature fluctuations. If you live here, you’ll want to prepare for a damp climate. Our best advice is to consult with professionals before installing spray foam insulation.
What Happens When Spray Foam Gets Wet?
When spray foam gets wet, a number of damp issues may arise. It’s a huge problem, especially with the UK’s climate.
No doubt, damaged spray foam must be removed. Otherwise, here’s what can happen.
- Timber Rot: Rainwater can leak into the spray foam. As the rainwater collects, it can cause the timber to rot.
- Mould Growth: In cases of improper installation, gaps in the spray foam application can let water and moisture in. When this happens, mould can grow behind or directly on the spray foam.
- Property Damage: Mould growth and timber rot inevitably lead to damage. The spray foam causes structural problems, resulting in costly repairs and property devaluation.
How Can You Tell If Your Spray Foam Needs Replacement?
Spray foam insulation doesn’t last forever, especially when it gets wet. These are some signs that you need to replace your spray foam immediately.
- Musty Odours: Musty smells can happen when there’s mould and trapped moisture within your walls. Your spray foam may not have been installed properly and is in need of replacement.
- Cracking or Warping: Warped wooden beams and cracking walls are signs that the spray foam is degrading.
- Sagging or Warping: If your ceiling is sagging, it’s a sign that the spray foam expanded too much during installation. The spray foam must be replaced to avoid problems down the road.
- Damp Patches: Visible mould growth and damp patches on your walls can be caused by damaged insulation. Look out for wet spots or areas that are darker in colour.
- High Energy Bills: Unexplained increases to your energy bills can mean that your insulation is no longer effective. The spray foam may be compromised and is due for removal.
- Pest Infestation: Insects and rodents nest within cracks in insulation material. Having termites is also a sign that your timber may be rotting.
Should You Use Spray Foam in the UK?
Spray foam can be a good insulation material when installed correctly by licensed professionals. However, it may not be the best option in the long run and especially where moisture concerns are. This is true for both types of insulation as open-cell moisture resistance and closed-cell differ very little – both will ultimately fail if exposed to damp conditions.
UK homeowners can face issues with mortgage lenders due to spray foam installations. In 2024, over 25% of the UK’s biggest mortgage lenders refused to lend to homes with spray foam insulation present. The reason for this is poor fittings that trap moisture, leading to decaying structures.
Spray foam insulation can cause unexpected costs. Some homeowners even had to replace their roofs entirely, which may cost up to £10,000!
Spray Foam Alternatives
So, which insulation material is best in the UK? According to the Energy Saving Trust, insulation materials you can use include mineral wool, fibreglass, foam boards, cork, or wood.
The material you use should depend on the following.
- Dampness: If your home has a pre-existing damp problem, you should go for vapour-permeable insulation, like mineral wool. Be sure the surface is dry and in good condition before installing insulation.
- Ventilation: Insulation can alter the way air travels around your space. Wood fibre is a great option for those who need highly breathable insulation.
- Space: Some insulation materials are bulkier than others. Thinner foam boards may be the better option for those with limited space.
- Price: Installing insulation doesn’t have to break the bank. Affordable insulation materials include fibreglass and mineral wool.
There’s no one-size-fits-all answer to insulation. You should always consult a professional before installation.
How Do You Remove Spray Foam?
In general, removing spray foam is no easy task. It involves using serrated blades and countless hours of work. Professional removers may use cutting-edge dry ice blasting or similar technology.
If you are attempting DIY removal of spray foam, you run the risk of damaging the structure, pipes, or wiring underneath.
Here’s where we come in.
We work by creating a partnership of professional spray foam removal specialists. Expert removers will carefully assess your insulation and use the right tools to remove the spray foam thoroughly. This eliminates the risk of damage and the potential costs that can happen through DIY foam removals.
Hiring a professional is the safest and most efficient way to clear spray foam insulation from your home.
We can give you peace of mind and save you time and effort!
Are You Concerned With Spray Foam Issues? Here’s How We Can Help
If you’re dealing with spray foam insulation problems, then you’re not alone. Today, many UK homeowners are facing issues caused by spray foam such as mould and structural damage or even mortgage issues.
The good news is you can overcome spray foam issues, no matter how serious the problem is.
National Spray Foam Removal closely works with spray foam removal partners who offer competitive prices. All you have to do is fill in the form on the page, and a spray foam removal company will be in touch to provide you with a free no-obligation quotation as soon as possible.
Final Thoughts
So, is spray foam insulation waterproof? The quick answer is no, it isn’t.
Spray foam may seem like an easy solution for insulation. Yet, with the UK’s weather, it may not be the best option. Unfortunately, spray foam can accumulate moisture and eventually cause damage to your home.
Before your timber rots, it’s important to replace damaged spray foam. National Spray Foam Removal can help with that.
Whether you’re exploring removal options or you’re simply looking for advice, we’re here to guide you. You can reach out to us today for a free consultation and quotation!
