Homeowner’s concerns: “The downstairs bedroom is cold and the family room above our garage is hot in the summer.”
Homeowner’s goals: “Reduce ice buildup in the back of the house above the kitchen, lower energy costs, and reduce summer heat cost in the family room.”
Primary issues: Ice dams on the north side of the house are being caused by insulation and air barrier gaps on the sloped ceiling, kitchen soffit, and dormer walls.
The house has a high air infiltration rate due to the inadequate air barriers in the family room attic.
The main attic fiberglass insulation should be replaced so that the entire flat attic plane can be air sealed. This would be relatively easy to do when the home is being re-roofed.
Reinsulation & Air Sealing
Insulation: In the attic on both sides of the storage area and the floor above the master bath: air seal with spray foam and/or dense-pack cellulose contained by stapled netting.
Above the kitchen soffit, from the side of the dormer wall and slant rafter cavity: spray the side wall with 3” of foam and cap the corner. Inject cellulose into the rafter bay between the dormer wall and family room to 16” deep loose fill.
Family room flat attic: Remove poorly placed fiberglass insulation and air seal. Inject 16” of loose-fill cellulose over the attic flat.
Kitchen soffit: Spray foam 7” into rafter bays from the eave to the dormer wall and all along the top of the wall above the soffit. Also, add cellulose insulation in the kitchen soffit.
Clear story: Spray foam 5.5” of spray foam on all four sides.
|Blower Door Test Before Work
|Blower Door Test After work
|% Reduction in Air Leakage
|Blower Door Change
|Heat Energy Savings
|Blower Door Decrease/ $
|Heat Energy Savings/ $
|Incentives received from Efficiency Vermont
|Incentive $/ Contract $
|0.32896% / $1