EXISTING HOMES
WA 1.0—Introduction
This section applies to exterior walls and buffered walls adjacent to unconditioned areas, such as garages. Closed walls shall be insulated to R-11 or the highest practical R-value. Insulation shall not be installed in wall cavities that serve as air ducts for heating or cooling. Cavities containing wall-mounted heaters shall not be insulated unless there is blocking to prevent contact with insulation. For inspection purposes, the contractor may be required to open and replug selected entry holes at the discretion of Existing Homes. An infrared camera will be used by Existing Homes Quality Control staff to identify consistency of thermal quality and adherence with these specifications. Insulation shall be installed to reduce heat loss between conditioned and unconditioned spaces or to the outside of the house.
To qualify for an Existing Homes incentive, existing condition of wall insulation must be R-4 or less, and all cavities in all exterior walls must be insulated to R-11, or completely filled.
All accessible exterior wall cavities, regardless of eligibility for incentives, must meet the applicable requirements to be considered a complete measure, unless a requirement is waived by Existing Homes or physical barriers exist (see section IN 1.5). Areas where existing insulation is greater than R-4 are not eligible for incentives. However, areas where existing insulation is greater than R-4 must meet all applicable specifications so that areas where existing insulation is less than R-4 may qualify for an incentive.
WA 1.1—Knob and Tube Wiring
Before installing insulation in cavities with active knob and tube wiring, Existing Homes recommends having wiring inspected and approved in writing by a licensed electrician. Insulating walls with active knob and tube wiring shall be at the discretion of the contractor and homeowner, and adhere to state and local code.
WA 1.2—Insulating Closed Walls
This section refers to exterior walls and buffered walls adjacent to unconditioned areas, such as garages or knee walls. All cavities in all walls shall be filled, including small cavities above, below and on the sides of windows and doors. Use of an infra-red camera is strongly encouraged to identify such cavities, and due diligence shall be applied to ensure a consistent level of installed insulation.
WA 1.3—Plugs and Finish Work
Plugs shall be sealed, weatherproofed and ready to paint. Plugs shall not be vented. Plugs shall be made of material that will not shrink or expand, which would result in damage to the siding or finish. If the surface of the plug is below the surface of the siding, the hole shall be filled with non-shrinking, waterproof filler. If siding is removed and holes are drilled in the sub-siding, the holes shall be plugged.
WA 1.4—Removing and Replacing Siding
If possible and with homeowner permission, siding should be removed to access wall cavities. Before replacing siding, holes shall be filled with fitted plugs or covered with tar paper, counter flashed and stapled. Shingles or shakes shall be nailed every 4” with a minimum 4d galvanized finish nail and at each corner. Clapboard-type siding shall be nailed at every wall stud or 16” on center. All replaced siding shall use galvanized or corrosion-resistant nails and be re-installed in a professional manner. Any raw wood shall be primed or sealed.
WA 1.5—Open Wall
Open walls which separate conditioned and unconditioned spaces, such as garages adjacent to a conditioned space, shall be sealed for air leakage, insulated to a minimum of R-15 (or the cavity must be filled), and covered with a vapor-permeable air barrier to limit human contact in compliance with the requirements of
AT 2.7—Knee walls in Attic Areas. See IN 1.8 for the eligibility requirements for homes without intact interior wall coverings.
WA 1.6—Interior Installations
Walls that are inaccessible from the exterior shall be filled from the interior, with homeowner's permission.