External Wall Insulation (EWI)

Fundamentally, external insulation material is wrapped around the property to prevent cold air from entering the home. Therefore, this action not only keeps the home warmer in the winter, but it would also keep the home cooler during the summer. Remember, some homes are complex and may need very different solutions to provide thermal permeability and moisture resistance.

Typically, external insulation is suitable only over a cavity wall construction. The cavity is first pumped with insulation foam before the external insulation is fitted (and will have to provide a document stating as such). Note, as a general rule, houses built with ‘cavity or hollow’ blocks are not suitable for external wall insulation. Because cavity/hollow block walls cannot be pumped and filled, it rules out an integral part of the external insulation solution. For these houses Internal wall insulation (IWI) is a more suitable option.

External insulation systems can be made from a number of different materials such as:

• Expanded polystyrene boards

• Wood fiber

• Mineral wool slabs

These are installed in layers using mechanical fixings to the outer surface of the wall. The final insulation board is plastered with a special layer of render to complete the appearance. This render, ideally, can only be done during warm weather or in dry weather not below 5 degrees.

Most people don’t realize that all the existing fitments on your external wall must be taken into consideration, as they will have to be disconnected and re-attached to the newly insulated walls e.g.

• electricity cables

• alarms

• satellite dishes

• electricity and gas meter boxes

• any other external fixings, ie. gates, pillars, shores, drains, etc.

If your electricity is supplied by external cable you may need to have this disconnected and reconnected by ESB Networks. This can cause delay in getting started.

We install higher density boards behind external fixings to carry their weight and put a layer of insulation board over that. We have different types of board for high moisture areas and also different types of finishes to cope with extreme weather conditions.

When we survey your home we don’t just consider external wall insulation. How your house was constructed originally may make it unsuitable for some insulation methods. We will consider the best overall solution considering all possible insulation options and will advise you accordingly. This is an integral part of our service.