Cavity Wall Insulation

Why Install Cavity Wall Insulation?

The majority of properties built since the 1930’s consist of two ‘Skins'(often brickwork or blockwork) which are separated by a hollow space i.e. a cavity. If the cavity in these properties is left un-insulated approximately 35% of the heat within the property can escape through the un-insulated walls.  By installing a high quality bonded bead system into the cavity of these properties (both existing and new build) we can provide an efficient and effective way to insulate the cavity and reduce this heat loss.

We offer a high quality bonded bead system which utilises two basic components: a specially-manufactured grade of closed cell polystyrene FRA thermal bead, which is coated with an air drying adhesive during the injection process.

Pre-installation Measures:

Prior to beads being installed, a survey will be carried out on the property to
determine its suitability for cavity wall insulation.

The Installation Process:

Drilling – A series of 22mm holes are drilled in the property. The drilling pattern has been designed to give a complete cavity fill every time, regardless of the shape or size of the building. All our installation vehicles are fitted with twin injection systems, allowing up to 300m² of cavity walls to be insulated in a single day. Cavity Wall Insulation - Drilling
Injection – The injection nozzle is then placed in each hole, the system is set into motion and the beads are injected into the cavity under pressure. This process is carried out on every injection hole from the lowest level to the highest and the special bonding agent allows the beads to flow freely until the cavity wall is completely filled. The adhesive then sets, forming the beads into a bonded homogeneous heat saving mass which will not shrink, crack, settle or be unduly affected by the removal of any of the outer brickwork. Cavity Wall Insulation - Injection
Cavity Wall Insulation - Silver Beads
Making Good – The specially adapted drilling pattern means that the number of holes required can be kept to a minimum and the process of refilling the holes to make them good is much easier. In new build properties the cavity can be drilled from inside the property allowing the holes to be covered when plastering. Cavity Wall Insulation - Making Good

Advantages of Bonded Bead Cavity Wall Systems:

  • Reduces heat loss
  • Reduces carbon dioxide emissions
  • Will not transmit moisture
  • Self Draining
  • Cavity remains breathable
  • Speedy installation
  • Minimum drilling and disruption
  • Will not crack or settle
  • Constant density
  • Can be installed in most weather climates
  • No site handling or storage
  • Improves living conditions
  • Full guarantee policy
  • FRA Bead (Fire Retardant Additive)
  • CFC & HCFC Free
  • Approved by British Board of Agrement

The term U-value is the rate at which heat passes through a wall: the higher the u-value the more rapidly heat is transmitted through the walls. Bonded bead U-Values will change when used in various constructions and varying cavity widths however typical U-Values and savings are outlined below. 

Typical U-value (w/m²k) ranges which could be achieved with the installation of silver bonded bead—depending on cavity width and construction
50mm—70 mm Cavity 90mm—100mm Cavity 120mm—130 mm Cavity 150mm Cavity
Brick 1700 kg/m³/ Block 2000 kg/m³/Plaster 0.51 — 0.43 0.31—0.27 0.24—0.22 0.20— 0.19
Brick 1700 kg/m³/Block 650 kg/m³/Plaster 0.43 — 0.32 0.28—0.24 0.23—0.20 0.19—0.17


Contact us today

For more information on our products and services or to arrange a free energy survey please contact us on 028 7962 7474 or email