Types of Wall Cavity Insulation

Rockwool cavity wall insulation:Rockwool insulation is the most common insulation used for domestic type properties. This insulation generates heat and is spun to produce a fibre material. Rockwool insulation is blown into the cavity, filing the gaps between outer walls of the building completely. This insulation does absorb waterso it is essential an active damp course is in place, the damp course is not bridged and brick face and mortar are sound with no damage. It can be used brick to brick or concrete block to brick as long as the cavity width is 50mm or more.

Polystyrene bead cavity wall insulation: Polystyrene beads are also used as cavity wall insulation; these are pumped into the wall mixed with an adhesive which will then bond the beads together to prevent them from spilling out the wall. This type of insulation is also used in narrow cavities. Polystyrene beads can allow any damp to move down the beads and be released so as not to soak and hold damp and transfer moisture into the property.

Foam cavity wall insulation: Expanding foam is used as cavity wall insulation; it requires holes drilled into the mortar joints of the brick wall as small as 8mm. Foam insulation is ideal for engineering bricks as larger holes would damage these types of brick due to larger holes being made for other types of insulation. Polystyrene beads are thought to be the best material followed by Rockwool.