Foam Insulation Board Over Windows

Instead you should use zip sheathing asphalt felt or housewrap as your wrb.

Foam insulation board over windows.

When to use foam board insulation. Flash the sheathing around the buck to the window opening with tape or liquid flashing before installing the exterior foam insulation. Insulating boards are just one of the many types of foam insulation. One common use of extruded polystyrene foam board is for foundation insulation panels.

Polyiso comes in several thicknesses and is used over house sheathing underneath siding or in attic spaces where its reflective properties are very effective. Shop at lowe s to find the foam sheeting you need for your next insulation project. If you choose asphalt felt or housewrap it should be installed between the wall sheathing and the rigid foam. For the foam sheathing to be an effective air barrier and provide the drainage plane the joints between the boards must be sealed.

Prepare a rough opening for a nail fin window over exterior rigid foam insulation. There are basically two types of reflective insulation that can be used by homeowners today. Even with all the joints sealed it is still not recommended to have a vertical joint in the sheathing occur over a window head. Polyisocyanurate is another option coming in as the densest and more expensive option for foam board.

Consider using spray foam insulation as well to seal smaller cracks and gaps. The first is a foam backed foil that is much like the blue foam insulation used on a home s outer shell. If your building has outie windows you should use the rigid foam or housewrap installed on the exterior side of the rigid foam as your wrb. This is an even more dense and more expensive foam board insulation.

Typically sold as sheet insulation in a standard size of 4 x 8 foam insulation panels can help reduce energy costs get a handle on moisture control and more.