Cavity Wall Insulation

The Energy Saving Trust (EST) states that having your cavity walls insulated as opposed to uninsulated, can save you in excess of £280 per year on your heating costs.

Check Eligibility


If your property is deemed to be conventionally constructed (most properties post, but not limited to, 1930’s onwards) it is likely to have a cavity (gap/void) between the external and internal walls.

We use the Threma-bead system, which consists of the polystyrene beads being injected into the cavity wall via our unique injection gun into a small hole in either the external or internal skin of the property. As the beads are pumped in, they are mixed with a binding agent forming a homogenous mass that fills the cavity void in its entirety, resulting in a protective barrier that gives permanent reduction in the heat loss to your home.

The materials are safe, do not affect the fire resistance of the building or allow water to cross the cavity and, for as long as it is left undisturbed, it is structurally sound for the life of the property.

Cavity Wall Insulation Installation

25 year, independent backed, quality assurance guarantee.

The external wall of your property needs to be in good order before we start this process, and we will of course advise should there be any issues impending the install.

All cavity wall insulation installs will benefit from a retrofit assessment, along with additional checks being sent to a chartered surveyor first – who will assess the property type prior to install.

This pre-check takes things like the property construction, wall thickness and property location into consideration.

There are many factors which can affect the viability of cavity wall insulation and the insulation will not be installed unless the property meets all the necessary requirements.

Upon completion, you will be issued with a 25 year, independent backed, quality assurance guarantee. If we were to ever cease trading, your guarantee will still be in effect.


Understanding of thermal energy efficiency has advanced considerably over the years. In decades past, other methods of cavity wall insulation have been used where they simply should not have.

If a cavity has been insulated with either the wrong material or in a high weather exposure area, then there is a good chance the old insulation has failed. This can be seen by mould patches appearing on internal walls where either water penetration is evident or voids (cold spots) form in the insulation.

Old methods incorporated a blown fibrous material which had no binding agent. As such, over time and with assistance of gravity, this insulation “sags” and leaves voids within the cavity once again.

This has a major detrimental effect upon the living quarters of the property and the only way to mitigate this is to remove the failed material.

At Eco Home Insulation will we check to see if there is a guarantee in place for your property – if so, we will guide you down the appropriate channels to action the guarantee. If not, we can remove the failed insulation as part of our assessment and issue you with a cavity clearance report.

We can then refill the cavity with Therma-bead – giving you the thermal qualities you should always have had, and more.