Pitched Roof Insulation Between Rafters

Both products are high performance pir insulation boards which have been specifically designed for this type of roof construction.

Pitched roof insulation between rafters. Warm pitched roof to create a warm pitched roof insulation such as kingspan kooltherm k7 pitched roof board should be fitted between and over the rafters. The current trend is for a warm roof where insulation is installed between the rafters thereby keeping the roof timbers warm. The best way to insulate a pitched roof is by installing insulation between and above the rafters. Using earthwool rafter roll between rafters and knauf insulated plasterboard below rafters with lr underlay pulled taught and insulation to fully depth of rafters note.

An efficient room in a roof in a new build property where over rafter insulation is not desirable. This approach can be used to create an unventilated roof structure helping to keep out unwanted drafts. For this method of pitched roof insulation we recommend using quinn therm qr roof insulation boards between the rafters and quinn therm ql kraft insulation boards below the rafters. Rafter line insulation maximise space and performance utilising a pitched roof as a usable living space is an effective way to maximise the square meterage of a residential development.

How to install pitched roof insulation above and between rafters insulation above the rafters 1. The amount of heat loss through cold bridging can be minimised by using another layer of insulation either above or below them. Install a timber stop batten across the rafters as shown in position c above with the batten equalling the thickness of the quinn therm insulation. Rafter sizes assumed to be 38mm wide at 600mm centres 6 3 bridging 10mm deeper than the insulation to account for the draped membrane.

The roof will typically be insulated above the rafter line creating what is most commonly known as a warm roof. Obviously heat will be lost through the rafters at a faster rate than it is lost through the insulation. On new build or replacement pitched roofs the ideal build up would be insulation fitted over and then between the rafters giving a big boost for airtightness image credit. As there s no insulation below rafters headroom is maximised creating more useable space.

When it comes to pitched roofs however adding a thick layer of insulation to the rafters can result in a depth of roof construction that may not suit every site meaning over rafter insulation sarking only is not a viable option. Arguably the most popular pitched roof solution installing insulation between and under the rafters uses the depth of the structural timbers to best effect.