4.1101.5 Exterior Wall Dense Packing

Topic: 
Walls
Subtopic: 
Preparation
Desired Outcome: 
Walls properly prepared to receive dense pack Dense pack The process of installing loose-fill insulation to reduce air flow and perform to a stated R-value insulation
TitleSpecification(s)Objective(s)
4.1101.5a
Preparation

Lead safety procedures will be followed

Cavities will be free of hazards, intact, and able to support dense pack Dense pack The process of installing loose-fill insulation to reduce air flow and perform to a stated R-value pressures

Drilling hazards (e.g., wiring, venting, fuel piping) will be located

Blocking will be installed around:

  • All openings to inside of the crawl space and basement for fibrous material
  • High temperature fire-rated materials
  • Wiring and electrical hazards
  • Heat sources

Access to exterior wall cavities will be gained, sheathing will be drilled as needed and probed to locate each cavity, wall studs, and blockers

When accessing wall cavities, the interior will be masked to control dust during drilling

Electricity supply will be confirmed and will support blowing machine power demand

Blowing machine pressure test will be performed with air on highest level, feed off, and gate closed

Hose outlet pressure will be at least 80 IWC IWC Inches of water column or 2.9 psi Psi Pounds per square inch for cellulose insulation; for other types of dense pack Dense pack The process of installing loose-fill insulation to reduce air flow and perform to a stated R-value insulation, check manufacturer specification for blowing machine set up

Prevent damage to the house

Provide a clean work space

Provide thorough access to allow 100% coverage

Ensure proper equipment and process results in consistent density

Prevent settling and retard air flow through cavities

Protect worker and occupant health

4.1101.5b
Exterior dense pack Dense pack The process of installing loose-fill insulation to reduce air flow and perform to a stated R-value

Using fill tube, 100% of each cavity will be filled to a consistent density:

  • Blown fiberglass, mineral fiber, rock and slag wool, or spray foam used in an enclosed cavity will be installed at or above the manufacturer recommended density to limit air flow that corresponds to an air permeance value of 3.5 cubic feet per minute per square foot at 50 pascals
  • Cellulose material will be installed to a minimum density of 3.5 pounds per cubic foot when the wall sheathing and interior cladding will endure this level of pressure
  • Loose fiberglass material will be installed and will be specifically approved for air flow resistance to a minimum density in accordance with manufacturer specifications
  • The number of bags installed will be confirmed and will match the number to achieve 1.5-1.6 pounds per cubic foot
  • 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