Cavity – Most recent houses have a cavity build construction type. This is two layers of brick or block with a gap in the middle. This gap is then filled with insulation depending on the depth of the cavity and also the supplier recommendations.
Solid wall – Quite often these may be refereed too hard to treat homes and this is where you really do need specialist advice as getting this wrong will ultimately cost you financially, in your health and also the health of the building as well. However, in brief there are two main types of solid wall insulation. Internal Wall Insulation (IWI) and External Wall Insulation (EWI). IWI can come in many forms and it’s very important that is it both specified and installed correctly. The first question that needs answered is do you need a breathable (Vapour Open) system or a non-breathable (Vapour Tight) system. For really old buildings designers and specifiers will usually use vapour open materials like Wood Fibre or SpaceLoft insulation which are finished with a vapour open lime, clay, or other natural based finishes. However, for more modern buildings that just want to top up or improve their insulation and they are not breathable the most common types of insulation here are usually PIR rigid board insulation. These are fitted in many different ways but as with all IWI it is vital that they are fitted by a qualified specialise insulation installer to ensure you do not have the risk of interstitial condensation or other problems associated with poorly fitted insulation.
EWI can also come in many different forms and there are a lot of suppliers out there for the materials to insulate the external skin of your house. One key advantage of EWI is that it gives a new appearance to the outside of the house. This usually comes in the form of insulated boards that are stuck and fixed onto the outside of the house and they are then finished with a base coat plaster with a reinforcing mesh in it and then finished with a coloured render top coat.
With all solid wall insulation, it is really important that you deal with the smaller details as failing to do this may result in damaging the building fabric or causing unseen problems like condensation
(Sweating) and or mould growth that can be detrimental to the health of the occupants and the building fabric. The details are commonly referred to Thermal Bridging or cold bridging and include areas like door and window reveals, return walls, or any junction that is in contact with the outside.