Under floor insulation homeowners are confused by the various types of insulation available. It is important to find the right solution for your property. Cavity wall insulation is injected into the gap between the inner and outer leaves of brickwork that make up cavity walls. It is a common way to improve the energy efficiency of your home and reduce your heating costs.

Enhancing Building Performance: The Benefits of Exterior Insulation Cladding Systems

However, it is important to understand that EWI can cause damp problems when installed incorrectly. The damp problems are caused by the presence of moisture on the internal face of the wall, and the fact that the gap between the insulation boards allows rain to penetrate the outer leaf of the house and bridge the cavity via the insulation material, which can lead to condensation.

Before cavity walls were introduced, houses were built with either impermeable bricks that stop moisture penetration or ‘breathable’ stone and sand and cement render that allow moisture to penetrate (to a point) but evaporate before reaching the wall surface. The problem is that most EWI systems block this ability to evaporate, creating a trap and causing long term moisture ingress and ultimately damp problems.

To overcome this, a breathable EWI system can be used – such as mineral wool, polystyrene beads or EPS. These are blown into the wall and sealed with a bonding agent, which makes them less expensive than alternatives but also more effective at keeping the heat in while still being able to vaporise moisture.