Rigid Foam Insulation Rafters

Consider using high density r 30 batts which are as thick as r 25 batts but fit into 2x10 framing.

Rigid foam insulation rafters.

The 4 of rigid foam under the rafters at least give you r26. Measure the length and width between two rafters in your attic and transfer the measurements to a 4 ft by 8 ft of rigid foam insulation board. The rafters are 2 6 so there is 5 5 of depth under the roof deck to put layers of rigid foam into as a stack of pancakes between the rafters. There are currently three types of rigid foam board.

Rigid insulation is one of the best tools to reduce your energy costs. Think of the same example of a wall and attaching drywall with the tons of screws. But a 2x6 rafter with a 1 5 vent space would give you the ability to put 4 of rigid insulation r 26 in that space which was not filled. They keep your home at a comfortable temperature without the need to crank your heat.

Polystyrene can be fashioned into various items including shipping materials such as packing peanuts and coffee cups as well as sheets of foam board insulation. Rigid foam insulation also known as insulating boards provide high r values. However rigid foam insulation must be covered with a fire rated material when used on the interior of a building. You can also add rigid foam insulation under the rafters which adds r value and eliminates thermal bridging through wood rafters.

2 would be to create the baffle in the 1st place. I would also like to attach 4 x8 sheets of rigid foam at least 1 2 inch thick to the lower edge of the rafters to prevent thermal bridging. 2 snap a chalk line between the length measurements. Install it anywhere from the roof to the foundation.