Cavity Wall Insulation

Heatpac Employee holding injector
Heatpac employee holding pipe to pump in insulation inside propety

Cavity Wall Insulation is quick and easy to install.

A series of small holes are drilled into the mortar joints
on the external brickwork. Glass wool is then blown into the
holes until an effective heat seal is formed within the cavity.

The majority of work is carried out on the outside of your
home with minimal inconvenience to you.

We can insulate homes with different cavity specifications such as hard to treat/narrow cavity and partial fill.

A simple survey will establish if cavity wall insulation is
suitable for your home.

On completion, your home will be more energy efficient,
more comfortable, and easier to keep warm.

A 25 year Cavity Insulation Guarantee Agency (CIGA)
warranty is given on all cavity wall insulation work.
CIGA is an independent body set up by the Government.
The guarantee covers any defect in materials or workmanship
in connection with the installation, which will be rectified without charge. The guarantee remains valid for all subsequent owners of the property.
Click here for FAQ’s about Cavity Wall Insulation.



Q: How long will it take?
A: Between two to three hours for a three bed roomed semi-detached house.
Q: Will it make a mess?
A: No. The insulation is injected from the outside, so the installers will not be working in the house.
Q: What do they use as insulation?
A: The material used will most likely be mineral wool (or Isowool).
It is properly accredited as a building material, guaranteed by the Cavity Insulation Guarantee Agency (CIGA), and will be installed by a certified installer.
Q: Will the work be guaranteed?
A: Yes. The work will be guaranteed for 25 years by The Cavity Insulation Guarantee Agency (CIGA).
Q: Where can I find more information about home insulation?
A: Give us a call for FREE ADVICE on insulation and grants available:
0800 552 525

What Is Cavity Wall Insulation?

Most homes built since the 1920’s have cavity walls, i.e. an inner and an outer ‘skin’ with a gap between them. Filling this gap with insulation material improved the retention of heat on the inside of the property.

Methods to insulate your cavity walls:

  • Whitewool cavity wall insulation is a mineral fibre
  • Expanded Polystyrene Beads (EPS) are a high performance, injected, blown grey bead

Polystyrene beads are completely waterproof, so even if they do get wet, they will dry out without any lasting damage or adverse affect on your insulation.

Is My Property Suitable for Cavity Wall Insulation?

If your property was built after the 1920’s, you almost certainly have cavity walls. Older houses are more likely to have solid walls.

Your home will usually be suitable for cavity wall insulation if it meets these criteria:

  • Its external walls are unfilled cavity walls.
  • Your cavity is at least 50mm wide.
  • The masonry or brickwork of your property is in good condition.
  • It is more than 10 years old (most newer houses will have insulation already).
  • The walls are not exposed to driving rain.

Contact us today so we can check the condition of your current masonry or brickwork, and any existing insulation if it exists.

How Cavity Wall Insulation Is Installed?

You’ll need a registered installer to fit cavity wall insulation – it’s not a job you can do yourself.

The insulation material is injected through small holes drilled in the exterior brickwork. Once the installation is complete we make good all brickwork, blending in the installation work to retain the look of your property.

Cavity walls are filled with an insulating material; commonly-used materials include mineral wool, polystyrene beads or foam. Insulating cavity walls will help trap heat and prevent warmth from escaping.

A typical installation usually takes less than half a day.

How Much Does Cavity Wall Insulation Cost?

The average cost of cavity wall insulation can be difficult to determine.

We price each job on an individual basis, as the scope of the required work can vary, especially as we take on jobs of any size.

Although looking at data from the Energy Saving Trust you could save £145-400 a year by insulating cavity walls. You can get an estimate of your savings from the Energy Saving Trust (EST).

Figures based on a typical gas-heated home.

Cavity Wall Insulation Services

All of our work is guaranteed, and is carried out by qualified professionals. We also extract and remove insulation that’s damp and causing problems, and replace/install loft insulation.

  • The best qualified teams in the UK
  • A guideline price over the telephone where possible
  • Free help and advice in diagnosing cavity wall problems
  • Detailed surveying capability (which may include thermal imaging and moisture monitoring where required)
  • Certificate provided on completion of work