Insulating materials must be installed according to the insulation manufacturer's installation instructions and the requirements set forth in table 1 to 460.103, which is adapted from section R402 of the 2021 IECC.
Table 1 to § 460.103—Installation of Insulation
| Component
| Installation requirements
|
|---|
| General | Air-permeable insulation must not be used as a material to establish the air barrier.
|
| Access hatches, panels, and doors | Access hatches, panels, and doors between conditioned space and unconditioned space, such as attics and crawlspaces, must be insulated to a level equivalent to the insulation of the surrounding surface, must provide access to all equipment that prevents damaging or compressing the insulation, and must provide a wood-framed or equivalent baffle or retainer when loose fill insulation is installed within an exterior ceiling assembly to retain the insulation both on the access hatch, panel, or door and within the building thermal envelope.
|
| Baffles | For air-permeable insulations in vented attics, a baffle must be installed adjacent to soffit and eave vents. Baffles, when used in conjunction with eave venting, must be constructed using a solid material, maintain an opening equal or greater than the size of the vents, and extend over the top of the attic insulation.
|
| Ceiling or attic | The insulation in any dropped ceiling or dropped soffit must be aligned with the air barrier.
|
| Narrow cavities | Batts to be installed in narrow cavities must be cut to fit or narrow cavities must be filled with insulation that upon installation readily conforms to the available cavity space.
|
| Rim joists | Rim joists must be insulated such that the insulation maintain permanent contact with the exterior rim board.
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| Shower or tub adjacent to exterior wall | Exterior walls adjacent to showers and tubs must be insulated.
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| Walls | Air permeable exterior building thermal envelope insulation for framed exterior walls must completely fill the cavity, including within stud bays caused by blocking lay flats or headers. |