Cantilever Floor Insulation Detail

Of course you need to protect the rigid foam from abuse with a layer of plywood osb or soffit material.

Cantilever floor insulation detail.

When it comes to floor assemblies the stack effect works in your favor lowering rather than increasing the risk of moisture accumulation. In addition to floors other cantilevered architectural features may require insulation. Measure the size of the opening between the floor joists underneath the cantilevered overhang. This material has a few drawbacks as it still allows some airflow through the floor and is known to trap allergens and moisture which can leave.

Any suggestions would be greatly appreciated. You should only put in fiberglass insulation if you can access the cantilevered floor joist from a basement or crawl space. You can use rigid foam of any thickness on the underside of a cantilevered floor in your climate zone. I am working on a project where the main floor is cantilevered over the concrete foundation wall.

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. If the floor is over a garage and has not already been insulated however it is recommended that each joist bay be filled with insulation. Usually only the cantilevered portion of the floor needs to be insulated. Installing cellulose via the crawl space is fairly simple as it is just blowing the material into the floor joists.

2 cut pieces of 1 inch nonstructural sheathing board or 1 inch rigid foam sheathing to fit inside the. Cellulose cantilevered floor insulation. The details i do have show a cantilever over a wood frame wall not a concrete foundation wall.