Cantilever Floor Joisted Cavities Batt Insulation

Verify that installation area is free of:

active water leaks, fuel leaks (i.e., gas, oil, propane), and pest intrusions

energized knob and tube wiring

uncovered electrical junctions

improperly terminated devices (ventilation fans, dryers, plumbing stacks, condensate lines, combustion appliance flues/chimneys, etc.)

unshielded high-temperature devices (non-IC rated recessed lights, chimneys, flues, vents, etc.) unless they are zero clearance devices

insulation escape openings

Verify that installation area is:

intact, able to support insulation weight, and air sealed

Select insulation that has a flame spread and smoke development index of 25/450 or less when tested in accordance with ASTM E84 or UL 723

Remove any existing insulation or vapor barrier materials from installation area

Install airtight blocking between each floor joist at the interior edge of the exterior wall plate

Install batt insulation to prescribed R-value in every joist bay in full contact with the air barrier and all sides of the cavity without gaps, voids, compressions, or misalignments

If batt contains a facing material install it in contact with the conditioned space

Secure batts in full contact with the pressure boundary using physical fasteners that do not compress the insulation and have a minimum service life of 20 years (e.g., strapping, netting, wood strips)

Mechanically fasten a continuous, airtight, rigid air barrier to underside of floor assembly that is suitable to withstand weather, moisture, and pest contact

Install durable exterior soffit material over the rigid enclosure materials

Post a dated receipt signed by the installer that minimally includes: Installed insulation type, coverage area, installed thickness, and installed R-value