Tiny Houses 2021
| COMPONENT | AIR BARRIER CRITERIA | INSULATION INSTALLATION CRITERIA |
|---|---|---|
| General requirements |
A continuous air barrier shall be installed in the building envelope. Breaks or joints in the air barrier shall be sealed. |
Air-permeable insulation shall not be used as a sealing material. |
| Ceiling/attic |
The air barrier in any dropped ceiling or soffit shall be aligned with the insulation and any gaps in the air barrier shall be sealed. Access openings, drop-down stairs or knee wall doors to unconditioned attic spaces shall be sealed. |
The insulation in any dropped ceiling/soffit shall be aligned with the air barrier. |
| Walls |
The junction of the foundation and sill plate shall be sealed. The junction of the top plate and the top of exterior walls shall be sealed. Knee walls shall be sealed. |
Cavities within corners and headers of frame walls shall be insulated by completely filling the cavity with a material having a thermal resistance, R-value, of not less than R-3 per inch. Exterior thermal envelope insulation for framed walls shall be installed in substantial contact and continuous alignment with the air barrier. |
| Windows, skylights and doors |
The space between framing and skylights, and the jambs of windows and doors, shall be sealed. |
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| Rim joists |
Rim joists shall include an exterior air barrier.ᵇ The junctions of the rim board to the sill plate and the rim board and the subfloor shall be air sealed. |
Rim joists shall be insulated so that the insulation maintains permanent contact with the exterior rim board.ᵇ |
| Floors, including cantilevered floors and floors above garages |
The air barrier shall be installed at any exposed edge of insulation. |
Floor framing cavity insulation shall be installed to maintain permanent contact with the underside of subfloor decking. Alternatively, floor framing cavity insulation shall be in contact with the top side of sheathing, or continuous insulation installed on the underside of floor framing and extending from the bottom to the top of all perimeter floor framing members. |
| Basement, crawl space, and slab foundations |
Exposed earth in unvented crawl spaces shall be covered with a Class I vapor retarder/air barrier in accordance with Section N1102.2.10. Penetrations through concrete foundation walls and slabs shall be air sealed. Class I vapor retarders shall not be used as an air barrier on below-grade walls and shall be installed in accordance with Section R702.7. |
Crawl space insulation, where provided instead of floor insulation, shall be installed in accordance with Section N1102.2.10. Conditioned basement foundation wall insulation shall be installed in accordance with Section N1102.2.8.1. Slab-on-grade floor insulation shall be installed in accordance with Section N1102.2.10. |
| Shafts, penetrations |
Duct and flue shafts and other similar penetrations to exterior or unconditioned space shall be sealed. Utility penetrations of the air barrier shall be caulked, gasketed or otherwise sealed and shall allow for expansion, contraction of materials and mechanical vibration. |
Insulation shall be fitted tightly around utilities passing through shafts and penetrations in the building thermal envelope to maintain required R-value. |
| Narrow cavities |
Narrow cavities of 1 inch or less that are not able to be insulated shall be air sealed. |
Batts to be installed in narrow cavities shall be cut to fit or narrow cavities shall be filled with insulation that on installation readily conforms to the available cavity space. |
| Garage separation |
Air sealing shall be provided between the garage and conditioned spaces. |
Insulated portions of the garage separation assembly shall be installed in accordance with Sections N1101.10–N1101.12 and N1102.2.7. |