N1102.4 (R402.4) Air Leakage (Mandatory)
The components of the building thermal envelope as indicated in Table N118.104.22.168 shall be installed in accordance with the manufacturer's instructions and the criteria indicated in Table N122.214.171.124, as applicable to the method of construction. Where required by the building official, an approved third party shall inspect all components and verify compliance.
TABLE N1126.96.36.199 (R402.4.1.1)
AIR BARRIER AND INSULATION INSTALLATIONa
|COMPONENT||AIR BARRIER CRITERIA||INSULATION INSTALLATION CRITERIA|
|General requirements||A continuous air barrier shall be installed in the building|
envelope.The exterior thermal envelope contains a continuous air
barrier.Breaks or joints in the air barrier shall be sealed.
|Air-permeable insulation shall not be used as a sealing|
|Ceiling/attic||The air barrier in any dropped ceiling or soffit shall be|
aligned with the insulation and any gaps in the air barriersealed.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 wallsshall be sealed.
Knee walls shall be sealed.
|Cavities within corners and headers of frame walls|
shall be insulated by completely filling the cavity witha material having a thermal resistance of not less than R-3 per inch.
Exterior thermal envelope insulation for framed wallsshall be installed in substantial contact and in 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.
|Rim joists||Rim joists shall include the air barrier.||Rim joists shall be insulated.|
|Floors including cantilevered|
floors and floors abovegarages.
|The air barrier shall be installed at any exposed edge of|
|Floor framing cavity insulation shall be installed to|
maintain permanent contact with the underside ofsubfloor decking. Alternatively, floor framing cavity
insulation shall be in contact with the top side ofsheathing or continuous insulation installed on the
underside of floor framing; and extending from thebottom to the top of all perimeter floor framing
|Crawl space walls||Exposed earth in unvented crawl spaces shall be covered|
with a Class I vapor retarder with overlapping joints taped.
|Crawl space insulation, where provided instead of floor|
insulation, shall be permanently attached to the walls.
|Shafts, penetrations||Duct shafts, utility penetrations, and flue shafts opening to|
exterior or unconditioned space shall be sealed.
|Narrow cavities||—||Batts to be installed in narrow cavities shall be cut to fit|
or narrow cavities shall be filled with insulation that oninstallation readily conforms to the available cavity
|Garage separation||Air sealing shall be provided between the garage and||—|
|Recessed lighting||Recessed light fixtures installed in the building thermal|
envelope shall be sealed to the finished surface.
|Recessed light fixtures installed in the building thermal|
envelope shall be air tight and IC rated.
|Plumbing and wiring||—||In exterior walls, batt insulation shall be cut neatly to fit|
around wiring and plumbing or insulation that oninstallation, readily conforms to available space, shall
extend behind piping and wiring.
|Shower/tub on exterior wall||The air barrier installed at exterior walls adjacent to|
showers and tubs shall separate the wall from the shower ortub.
|Exterior walls adjacent to showers and tubs shall be|
|Electrical/phone box on||The air barrier shall be installed behind electrical and|
communication boxes. Alternatively, air-sealed boxes shallbe installed.
|HVAC register boots||HVAC supply and return register boots that penetrate|
building thermal envelope shall be sealed to the subfloor,wall covering or ceiling penetrated by the boot.
|Concealed sprinklers||Where required to be sealed, concealed fire sprinklers shall|
only be sealed in a manner that is recommended by themanufacturer. Caulking or other adhesive sealants shall not
be used to fill voids between fire sprinkler cover plates andwalls or ceilings.
- Inspection of log walls shall be in accordance with the provisions of ICC 400.
The building or dwelling unit shall be tested and verified as having an air leakage rate of not exceeding five air changes per hour in Climate Zones 1 and 2, and three air changes per hour in Climate Zones 3 through 8. Testing shall be conducted in accordance with RESNET/ICC 380, ASTM E779 or ASTM E1827 and reported at a pressure of 0.2 inch w.g. (50 Pascals). Where required by the building official, testing shall be conducted by an approved third party. A written report of the results of the test shall be signed by the party conducting the test and provided to the building official. Testing shall be performed at any time after creation of all penetrations of the building thermal envelope.
- Exterior windows and doors, fireplace and stove doors shall be closed, but not sealed, beyond the intended weatherstripping or other infiltration control measures.
- Dampers including exhaust, intake, makeup air, backdraft and flue dampers shall be closed, but not sealed beyond intended infiltration control measures.
- Interior doors, where installed at the time of the test, shall be open.
- Exterior or interior terminations for continuous ventilation systems shall be sealed.
- Heating and cooling systems, where installed at the time of the test, shall be turned off.
- Supply and return registers, where installed at the time of the test, shall be fully open.
Windows, skylights and sliding glass doors shall have an air infiltration rate of not greater than 0.3 cfm per square foot (1.5 L/s/m2), and for swinging doors not greater than 0.5 cfm per square foot (2.6 L/s/m2), when tested in accordance with NFRC 400 or AAMA/WDMA/CSA 101/I.S.2/A440 by an accredited, independent laboratory and listed and labeled by the manufacturer.
Exception: Site-built windows, skylights and doors.
In Climate Zones 3 through 8, where open combustion air ducts provide combustion air to open combustion fuel-burning appliances, the appliances and combustion air opening shall be located outside the building thermal envelope or enclosed in a room that is isolated from inside the thermal envelope. Such rooms shall be sealed and insulated in accordance with the envelope requirements of Table N1102.1.2, where the walls, floors and ceilings shall meet a minimum of the basement wall R-value requirement. The door into the room shall be fully gasketed and any water lines and ducts in the room insulated in accordance with Section N1103. The combustion air duct shall be insulated where it passes through conditioned space to an R-value of not less than R-8.