Cantilever Floor Insulation Detail

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.

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. Any suggestions would be greatly appreciated. The details i do have show a cantilever over a wood frame wall not a concrete foundation wall. Installing cellulose via the crawl space is fairly simple as it is just blowing the material into the floor joists.

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. 2 cut pieces of 1 inch nonstructural sheathing board or 1 inch rigid foam sheathing to fit inside the. In addition to floors other cantilevered architectural features may require insulation. Fiberglass must be cut precisely to fill in the batts in the floor joists.

Of course you need to protect the rigid foam from abuse with a layer of plywood osb or soffit material. I am having a hard time finding details showing the sealnt barriers and insulation for the cantilevered floor. I am working on a project where the main floor is cantilevered over the concrete foundation wall. You can use rigid foam of any thickness on the underside of a cantilevered floor in your climate zone.

Measure the size of the opening between the floor joists underneath the cantilevered overhang. You should only put in fiberglass insulation if you can access the cantilevered floor joist from a basement or crawl space. Usually only the cantilevered portion of the floor needs to be insulated.