Rigid Foam Insulation Rafters

However rigid foam insulation must be covered with a fire rated material when used on the interior of a building.

Rigid foam insulation rafters.

You can also add rigid foam insulation under the rafters which adds r value and eliminates thermal bridging through wood rafters. 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. Rigid insulation is one of the best tools to reduce your energy costs. The 4 of rigid foam under the rafters at least give you r26.

Molded expanded polystyrene foam board. Install it anywhere from the roof to the foundation. 2 would be to create the baffle in the 1st place. 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.

Consider using high density r 30 batts which are as thick as r 25 batts but fit into 2x10 framing. 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. Think of the same example of a wall and attaching drywall with the tons of screws. Meps is a rigid board formed by molding polystyrene into boards.

2 snap a chalk line between the length measurements. 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. You can even place it under the foundation slab.