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
TitleSpecification(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

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/sq. ft. at 50 pascals, as measured using ASTM , SITE 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 at 50 pascals of pressure difference using  chemical smoke or other approved verification method by the authority having jurisdiction

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