If you re using fiberglass that number.
How to insulate overhangs and cantilevered floors.
While building a house insulating an overhang is relatively easy.
Inspect the existing wall and overhang framing for any deficiencies and make any corrections if necessary.
Install insulation without misalignments compressions gaps or voids to fill the cantilever floor cavity making full contact with the top bottom and sides of a cantilevered floor cavity cover the bottom of the insulated cantilever floor cavities with a rigid weather resistant solid blocking material such as plywood or house siding.
The blocking should be located above the bearing wall below.
If you re about to insulate a cantilevered floor the first step is to install blocking between the joists.
You ll need to be able to reach the underside of the cantilever from the outside too.
A cantilevered overhang can create more space in your home but it also must be insulated properly to make your home more energy efficient.
Upgrade a wall with a floor overhang or cantilever on an existing home by adding rigid insulating sheating and or closed cell spray foam insulation and air sealing as follows.
Once you ve determined that it s doable consider these tips on how to insulate cantilevered floor joists on overhangs on existing buildings retrofit.
Spray foam insulation or rigid board insulation can be used to insulate and air seal the cantilevered area.
How to insulate a cantilever overhang.
Final thoughts insulating floor deck cantilevers overhangs they keys to remember when insulating a deck cantilever like bay window floors 2nd floor overhangs and chimney chases if providing sufficient r value and preventing air infiltration.
A beam supported on one end in this case by the home while the opposite end overhangs past the exterior wall and carries a load people or floor.
To complete this task you will need access to the interior joist bays from the basement.
It s better for the blocking to be on the interior side of the bearing wall rather than the exterior side.
Installing cellulose via the crawl space is fairly simple as it is just blowing the material into the floor joists.
Builders only need to remember not nail off the subfloor over the cantilevered joists until after they have installed the insulation.
1 measure the size of the opening between the floor.
Cellulose insulation can be installed in the cantilever floor joists two ways through access from the crawl space or by drilling holes through the bottom of the overhang.
Even fiberglass can be used as long.