Which Cavity Wall Insulation

Which is the most suitable cavity wall insulation system

There are three main cavity wall insulation systems available in the UK today, but which is the most suitable for your home ?

We can offer the three main systems and give you impartial advice to help you select the most appropriate one for your house.

Blown fibre insulation
Blown fibre insulation Bonded beads
Bonded beads
in a wall cavity injecting Polyurethane foam insulation
Injecting Polyurethane insulation Polyurethane foam wall insulation
Polyurethane insulation randon-stone-house-leeds
Random stone houses are usually not suitable for mineral fibre

Blown Mineral fibre

Mineral wool Insulation also known as Rockwool, White Wool or Glass Wool is made from spun volcanic rock or glass. It is an entirely dry system which uses granulated fibre blown into an external cavity wall to a predetermined density. The mineral fibre is treated with a water repellent during the manufacturing process.

The material is blown into the cavity space through a series of holes. As with all forms of cavity wall insulation the work is carried out externally. Before installation can take place the cavity must be inspected to ensure the walls are suitable.

This system has been used widely throughout the UK since the 1960s. With a proven track record of performance mineral fibre is the most cost effective system and accounts for the majority of work carried out in the UK, and is guaranteed by the Cavity Guarantee Insulation Agency (CIGA).

Expanded polystyrene (EPS) beads

Regarded as a premium insulation system, thousands of small polystyrene beads are blown into the cavity space and bonded using a binding agent or PVA adhesive. The binding agent holds the beads in place and stops them settling or coming out of the cavity if any structural work is carried out at a later date.

During installation the free flowing beads flow easily into the cavity and so can often be used in 'problem' properties when the cavity might not be suitable for standard mineral wool. Bonded beads are often used to insulate properties made from stone or where the cavity is narrower than normal than the 50mm minimum allowed for mineral wool. Bonded beads are a more thermally efficent form of insulation than mineral wool.

EPS beads have very good thermal properties and are water repellent, they do not rot or decay and do not provide nutrient value for insects, parasites, or animal and plant life. Injecting bonded EPS beads requires the fewer drill holes than either the wool or PU foam (see below) systems.

The latest EPS Polystyrene bead systems provide an alternative to mineral fibre. The system is fully guaranteed and is covered by either a CIGA guarantee or the manufacturers own warranty.

See more information on EPS beads.

Polyurethane (PU) injected foam

Not to be confused with the now banned Urea Formaldehyde foam, Polyurethane foam is a form of wall insulation that can be suitable for 'random stone' walls or other properties with non-standard cavities. It has excellent thermal properties and with a “closed cell" structure it is totally water repellent.

This system has been used extensively through out the UK for over 20 years and has the added advantages of enhancing the structural strength of walls. Because it binds to the inner and outer walls it can be used in walls where the wall ties have failed. The material is injected into the cavity and expands filling all voids and gaps. It requires the most dense drill pattern of the three systems discussed here - and is also the most expensive.

If your home has “random" stone walls you may have already been told it is not suitable for cavity wall insulation. However it is possible that PU foam would be a suitable alternative.

The system is covered by a manufacturers warranty on labour & materials.

Call 01943 262111 today for no obligation advice on insulation systems.

Or you can complete our callback form and we'll call at a time that suits you.

British board of Agrément compliance

BBA certificates are independently issued for the installation of mineral wool, bonded bead, and Polyurethane Foam forms of insulation. These certificates govern the type of homes than can be insulated, and the way in which the insulation is installed.

CIGA warranty

CIGA is an industry body that provides a warranty for walls of a brick construction, or walls of a stone construction where the stone is cleanly cut or very well 'dressed'.

Bonded beads and Polyurethane foam are both covered by a 25 year manufacturer's warranty.

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