Insulation For Between Roof Rafters

Unfaced insulation has no tabs and stays in place with friction between the fiberglass and the rafters.

Insulation for between roof rafters.

Once up at roof level the between rafter boards can be cut accurately to fit the rafter spacings. The general advice we give is that you should always insulate between and above the rafters or between and under the rafters on our u value calculator we don t give an option for putting insulation between the rafters. Being lightweight they do not impose significant additional loads on existing structures. We would always recommend having a breathable membrane in place between the tiles and the rafters too to allow the roof to breathe.

Consider using high density r 30 batts which are as thick as r 25 batts but fit into 2x10 framing. You can also add rigid foam insulation under the rafters which adds r value and eliminates thermal bridging through wood rafters. When you use solid insulation board to create a warm loft the key thing to remember is ventilation you must keep a 50mm gap between the roof and the rigid insulation board. A vent baffle should be installed between the insulation and the roof decking to maintain the ventilation channel.

In this blog post we will be looking at insulating pitched roofs and why putting insulation just between the rafters isn t a viable solution. 7 staple sheets of 6 mil plastic over unfaced insulation to create a vapor barrier.