Whether you’re installing in a new build or converting your loft into a habitable room, insulating your pitched roof is important. It’s a great way to make your home more energy efficient and reduce your heating costs, not only that but it also helps the environment and minimises outside noise from entering into your home.
Adding insulation to your pitched roof creates a thermal barrier between you and the outside air, keeping warm air inside and cold air out. This can save you up to 25% in energy costs every year.
Pitched roof insulation can be installed either from the inside or the outside and is usually fitted between rafters, with the sarking felt placed over the insulation board and timber stop battens being nailed into the side of the rafters to allow for an air gap. This is the preferred method of installation as this allows for ventilation to take place.
If you decide to insulate your roof from the outside, you will need to install a breathable membrane to prevent moisture getting into the building structure and to ensure that there are sufficient gaps to allow for adequate ventilation. This is particularly useful in older buildings where the original permeable materials are missing.
Regardless of the option you choose to insulate your pitched roof, it is worth noting that Building Regulations (Part L) require insulation between the rafters of existing buildings to achieve a minimum U-value of 0.18 W/m2K.