Adding new space to your home is a great idea – especially when it can cost much more to move to a new bigger home. Your loft is one part of your home that is perfect for conversion as it will need very little additional building work, you don’t need any planning permission if you stick to the original space and it is dead space that is underused in most homes. But your loft will need to be carefully insulated as part of the conversion process and choosing the right type is an important part of the project.
The government encourages all homeowners to insulate the loft in order to maintain a comfortable temperature and to save on energy costs. It can prevent the build-up of heat in the loft and therefore the possibility of condensation. Any time that there is a large difference between the temperature in the loft compared to other parts of the home, condensation could develop. This can cause mould, rotten wood timbers and general damp. Insulation can help prevent this.
Insulation options for your loft
- Mineral wool/batts – this is the typical type of insulation that we are all used to. It comes in rolls of thick material that is simply laid between the floor joists. It is recommended that around 270mm of mineral wool insulation is used to gain the best result – however, this is deeper than the space on the floor of the loft and therefore can cause head height issues.
- Blown insulation – this is a loose insulation that is blown into the space between the floor joists and inside any walls. It tends to have a lower thermal value and it is hard to get a deep enough layer to give the result you want. Once again you have issues with head height in your conversion.
- Solid insulation board – as your loft will be boarded out to make it habitable, these insulation boards make a great option. They are often filled with foam and come in varying depths to achieve the right thermal value. The main issue with these is a lack of flexibility as they cannot fill small or awkward spaces effectively.
- Spray foam insulation – many loft conversions are now being insulated with spray foam. The material is sprayed between the floor, wall and roof joists and rafters, giving even coverage that has a great thermal value. Then the foam is simply covered with a plasterboard. In terms of flexibility, this offers the best coverage, although it is more expensive than other insulation types.
Whatever insulation you choose, you will need to check with building control to ensure that you have complied with the rules for your area. This will take into account the number of windows, the size of the space and the type of insulation used. Your local council will be able to advise.