Foam Board Insulation In Attic Rafters

For new construction use rigid boards to insulate slabs and the outside of foundation walls.

Foam board insulation in attic rafters.

Rigid foam board also known as foam board or insulation board can be an excellent option for insulation. Some types of thicker foam board insulation are available but they may need to be special ordered. They re much lighter and easier to work with than plywood sheets. Foam board insulation is easy to use and is a great diy way to add some insulation.

It comes in standard size 4 8 sheets and smaller sizes in many different thicknesses from 1 4 inch to 2 inches. Install them using panel adhesive or screws. By adding the insulation under the rafters to maintain a ventilated roof at a cost of say1600 for a r28 airsealed radiant barrier product with the ability to add more if needed at a later date how is that a bad idea if an air sealed attic floor w blown in will cost roughly the same and i still won t have a good environment for hvac etc. It is lightweight and easy to work with.

Working with home insulation boards insulation panels typically come in 4x8 foot sheets. The superattic system utilizes proprietary silverglo rigid foam insulation panels to fully seal and insulate the attic directly beneath the roof rafters and directly inside the gable ends. 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. Better than spray foam thermal break and relatively consistent r 30.

Here s how to use 3 layers of 2 inch polyiso foam board to meet code and keep your ne. A 4 by 8 board weighs next to nothing and can easily be cut to fit. Polyurethane or polystyrene spray foams can provide thorough coverage to roof rafters and attic walls in much less time than is needed for other materials. Smaller sizes are also available.

The superattic system creates a continuous air and insulation barrier directly beneath the attic roof with no thermal bridging to compromise energy. Loose fill or batt the common term for blanket insulation. For diy attic insulation you ve got two choices. Both can be added to uninsulated attics or layered over existing material.

Typical thicknesses range from inch to 2 inches with estimated r values of r 3 for the inch to r 10 for the 2 inch board.