It has long been recognised that wall insulation is an absolute must in our home, offices and factories. Up to 30% of the heat that is lost from our buildings is via the walls and a good cavity wall insulation installation will help to keep internal temperatures constant and reduce expenditure on energy bills.
Before installing cavity wall insulation it is obviously important to determine whether or not you already have it. Most modern houses have cavity wall insulation fitted as standard during construction so, if your home was built in the last 10 years it will almost certainly already have wall insulation and nothing needs to be done.
The next thing to check is whether your house has cavity walls or not. Generally speaking a cavity wall is wider than a solid wall as it consists of an outer and an inner skin of bricks with a space in between them (the cavity). If you can see the pattern of the bricks within the walls it may be easy to determine need wall insulation or not. If the bricks are laid lengthwise and also crosswise it is almost certain that you have a solid wall and you need internal wall insulation or external wall insulation instead of cavity wall insulation.
Internal wall insulation, as the name suggests, is applied to the internal wall of a house to form an artificial second skin to a solid wall. This gives a layer of insulation against the outer wall preventing it making contact with the inner skin and thus keeping the outer temperature from making contact with the inner surface.
If you determine that you do need cavity wall insulation then there are a number of materials that can be chosen between. The three most common are polystyrene, fiberglass wool, and expanding foam.
The first form of cavity wall insulation, polystyrene, is generally used as beads. Holes are drilled into the cavity and the beads are then poured or blown into the cavity. The access holes are then filled up to prevent the beads escaping. polystyrene is most commonly used in basement wall insulation as these have a very high resistance to the absorption of moisture and there is often a high moisture content in the cavities of a basement. The main drawback with polystyrene external wall insulation systems comes when you need to drill a hole through the wall after the cavity wall insulation has been installed. If you're not careful it will all run back out when you drill the hole and it will need to be re-installed when you are finished.
To avoid this expanding foam cavity wall insulation can be used. This is installed in the same way as the polystyrene wall insulation but it is installed as a liquid and then a chemical reaction takes place that causes it to expand and harden. This fills the cavity thus providing excellent insulation and has the added advantage that it will not run out if a hole needs to be drilled through the wall.
Whichever wall insulation method you choose ensure you consider all of the options before commissioning a wall insulation contractor to do the work or before attempting the job as a DIY task.
Modern houses have cavity wall insulation fitted as standard during construction