Insulating Sloped Roof 100mm

By martin holladay issue 256 dec 2015 jan 2016.

Insulating sloped roof 100mm. The main decision to make when insulating a pitched roof is if you are going to have a warm roof or a cold roof. It is also difficult to top up older insulation to the recommended depth as modern insulation is sold. The main difference between the two is the location of the insulation. Because of limited space between the roof sheathing and ceiling joists a low slope shed roof can be difficult to insulate properly.

If you plan to insulate a sloped roof you need to decide if you want a vented or an unvented assembly. Insulating a roof is perhaps the easiest of all the energy saving home improvements. An unvented assembly can perform well but it s important to get the details right to avoid sheathing rot. It must be remembered that just because a roof space is insulated and the floor boarded it does not mean that the room can be considered a habitable room for a full.

This will depend on the construction on your roof and if it is a refurbishment whether the roof tiles are going to be removed. It s worth insulating the sloping insides of a pitched roof in order to conserve heat if the space is to be used for anything except simple storage. In fact any insulation that is less then 100mm is likely to be old and is worth disposing of. If 180mm is to be installed then 100mm board might be introduced between the rafters there has to be a minimum 25mm air gap between the insulation and the underside of the tiles or slates with an 80mm board running across the rafters.