Insulate Between Roof Rafters

The benefits of insulating a building around the outside protecting the structure and effectively creating a tea cosy effect are well publicised.

Insulate between roof rafters.

Arguably the most popular pitched roof solution installing insulation between and under the rafters uses the depth of the structural timbers to best effect. For rolled insulation place it between roof rafters. An efficient room in a roof in a new build property where over rafter insulation is not desirable. Make sure it is flush against the wood as even a 1 inch gap can cause a 20 percent heating loss.

Common rafter depths range from 100mm to 200mm. Roof insulation refers to the practice of installing insulation on the roof slope both above and below the rafters. Then feed the rolled insulation under wires and pipe if either is present. If your attic is going to be converted into livable space then you will need to insulate the roof rafters.

Place the plastic sheeting on top of the rolled insulation. Install ventilation baffles into the space between the rafters before you install the insulation usually by stapling into place. This generally would not be a sufficient thickness to achieve the u values required to meet building regulations and more insulation would need to be added. 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.