Consider using high density r 30 batts which are as thick as r 25 batts but fit into 2x10 framing.
Insulation for between roof rafters.
Where the insulation does not fill the total rafter depth the low emissivity foil facings can gain additional thermal benefit from the air spaces they face.
We would always recommend having a breathable membrane in place between the tiles and the rafters too to allow the roof to breathe.
Modern u value targets mean installing insulation between rafters only is rarely a viable option.
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.
Unfaced insulation has no tabs and stays in place with friction between the fiberglass and the rafters.
7 staple sheets of 6 mil plastic over unfaced insulation to create a vapor barrier.
It allows insulation to be installed in a watertight roof either after the roof covering has been fixed on a new build or without disturbing an otherwise sound existing roof covering as part of a renovation.
Once up at roof level the between rafter boards can be cut accurately to fit the rafter spacings.
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.