4.1103.2 Additional Exterior Wall Cavities

Topic:

Walls

Subtopic:

Enclosed Walls

Desired Outcome:

Properly installed insulation reduces heat flow through walls and framing cavities inaccessible to other treatments

For supporting material, see Calculation of the Infiltration Credit and Referenced Standards.

Single-Family Homes

	Title	Specification(s)	Objective(s)
	4.1103.2a Location of cavities	Details remaining in or between completed wall sections will be located and accessed	Ensure the last gaps and framing edges in the thermal boundary Thermal boundary The separation between the interior and exterior environments of a building that slows heat flow , roof-wall joints, floor-wall joints, etc., are found and finished
	4.1103.2b Sealing	Backing will be provided and all newly uncovered openings will be sealed with air barriers, foam, or mastic, maintaining all required clearances	Ensure the air barrier Air barrier The separation between the interior and exterior environments of a building that slows air flow to the point that no smoke movement is visible at 50 pascals of pressure difference across the boundary is connected across all accessible house elements
	4.1103.2c Dense packing See redline change(s)	Using fill tube, 100% of each cavity will be filled to a consistent density: Cellulose insulation used in an enclosed cavity will be installed at 3.5 pounds per cubic foot or greater density Blown fiberglass, mineral fiber, or rock and slag wool used in an enclosed cavity will be installed at or above the manufacturer recommended density to limit airflow that corresponds to an air permeance value of 3.5 cfm CFM Cubic feet per minute /sq. ft. at 50 pascals, as measured using BPI BPI Building Performance Institute, www.bpi.org -102 "Standard for Air Resistance of Thermal Insulation Used in Retrofit Cavity Applications—Material Specification" or ASTM ASTM ASTM International, www.astm.org C 522, E 283, or E 2178; the number of bags installed will be confirmed and will match the number required on the coverage chart Insulation will be verified to prevent visible air movement using chemical smoke at 50 pascals of pressure difference	Eliminate voids and settling Minimize framing cavity air flows
	4.1103.2d Quality assurance	Completed wall sections will be viewed using infrared camera with blower door operating Any voids or low density areas will be drilled and re-packed	Establish air barrier Air barrier The separation between the interior and exterior environments of a building that slows air flow to the point that no smoke movement is visible at 50 pascals of pressure difference across the boundary and thermal boundary Thermal boundary The separation between the interior and exterior environments of a building that slows heat flow Confirm no voids or hidden air flows remain
	4.1103.2e Close holes	Installation holes will be plugged as follows: Exterior holes will be weather barrier patched Interior holes will be coated and patched to match original interior surface All construction debris and dust will be collected and removed	Ensure house is returned to watertight and clean condition
	4.1103.2f Onsite documentation	A dated receipt signed by the installer will be provided that includes: Coverage area Thickness R-value	Document job completion to contract specifications Confirm amount of insulation installed Comply with 16 CFR 460.17