Cavity Wall Insulation

Cavity Wall Insulation can save up to 25% on your heating costs if you have a ventilated cavity void with no insulation present. It has been an insulation process that has existed for many years, however, some older insulation materials such as fibre and Urea Formaldehyde are no longer recommended.

We offer two options for retrofit cavity walls. Resin bonded EPS beads are popular as a cost effective way to insulate a cavity wall whereas Closed Cell Polyurethane Injection Foam is deemed to be the most thermally efficient way to maximise the thermal performance in the cavity space available.


Cavity wall insulation can provide a monolithic thermal seal to reduce heat loss and prevent driving moisture


Good cavity wall insulation can help to reduce heat loss and prevent draughts from entering your home.


Good cavity wall insulation can help to reduce heat loss and prevent draughts from entering your home.

Closed Cell Injection Foam

Closed Cell Polyurethane Foam is injected into your cavity wall void via a series of drilled holes on the outside of your home. Its low thermal conductivity makes it the very best form of retrofit insulation material and it will last with the life of your property without slipping, shrinking or degrading. Carried out by an experienced professional, the gradual rise of the closed cell foam will completely fill the cavity void, much in the way a loaf of bread rises in the oven. Injection foam installations should be carried out with absolute care to avoid over expansion within the cavity and resulting structural damage. Closed cell foam can be classified as a flood defence barrier in cavity walls and will therefore not allow driving moisture from penetrating through into the home.


Resin Bonded EPS Beads

Resin Bonded EPS Beads are blown into a cavity wall void using just a few drill holes on each wall elevation. The process is fast, simple and low risk. They allow moisture that enters the wall cavity to fall down to the damp proof course and escape the wall, hence the reason they are coated with a waterproof resin material. Resin Bonded beads are around 35% less thermally efficient than Closed Cell Injection Foam and whilst more cost effective, their performance should be considered before choosing to proceed with an install. Whilst the EPS beads do not act as an absolute barrier against moisture ingress through walls, they do not promote the tracking of moisture from the outer wall to the inner wall and are therefore considered to be the next best alternative to Closed Cell Injection Foam.

Cavity Wall Insulation Extraction

Some older, failing cavity wall insulation materials can, in most scenarios, be extracted from the cavity wall by drilling a series of holes and using a a specialist vacuum to suck the insulation out. Commonly, cavity wall extraction may occur when there is a problem such as older fibre insulation that has broken down and slipped within the wall to create cold thermal bridging. Cavity wall extraction may be required if you are looking to upgrade the thermal performance of your wall, for example, replacing old blown fibre insulation with high performance injection foam. In most circumstances, the extraction process shouldn’t cause any damage to your homes structure and it should leave your wall cavity completely clear and free from problems. Most extraction jobs take a day or less.


What Cavity Wall Insulation is best?

The thermal performance of closed cell injection foam cannot be rivalled by any other retrofit cavity wall insulation product. It provides a seamless, monolithic thermal barrier that vastly reduces heat loss and stops moisture from tracking through the wall. With cavity wall insulation designed to be a long term solution, it’s important that you weigh up the choices before committing.


Can Cavity Wall Insulation cause damage?

Once installed, a fully fill of the cavity void should not cause future damage to the property. It is only when the insulation has been badly fitted or the materials haven’t been prepared properly that issues can occur. Older, outdated material such as fibre insulation tend to natural shrink, slip and degrade within the wall cavity which is why we do not install them nor recommend that you consider them.

What are the install dangers?

Our installers are very experienced and know what it takes to deliver a safe and compliant install. There are dangers with the install, particularly when the walls are filled too quickly which can lead to over expansion of the closed cell foam. It takes time and patience to get the install right. For resin bonded beads, there is little risk of any structural damage but its important that the beads fill the cavity void to prevent thermal bridging.

How much does Cavity Wall Insulation cost?

We charge per metre and the rates vary depending on volume. The lower the meterage, the higher the unit rate. In most circumstances, resin bonded beads will cost between £16 per metre and £26 per metre. For closed cell injection foam, the price per metre is significantly higher and you should budget for between £38 and £54 per square metre. This is dependent on the thickness of the cavity wall void.

How much can I save on my heating costs?

Cavity Wall Insulation can save up to 35% on your heating and cooling costs but this varies between different insulation materials. Resin Bonded Beads will likely save around a third less than closed cell injection foam for example. For the best, long-term thermal performance, we would recommend you choose between closed cell injection foam and resin bonded beads.

Do I get a warranty?

Yes, we offer a 25 year installer workmanship warranty on all of our installs. This warranty protects you against any defects that may arise if cavity wall insulation is badly fitted. When installed by a professional organisation, cavity wall insulation should be a problem-free install. We also issue a products warranty from the insulation materials manufacturer.

Find Out More

Contact our team to find out more about cavity wall insulation.