The wall and blown-in attic insulation in my fairly new house are at recommended levels, but my utility bills are still too high. What other areas should I check for inefficiency?—Ronnie J.
1 Attic attack
Since you have blown-in attic insulation, check its depth. It may have settled and no longer reaches the required depth and R-value for your climate. (The U.S. Department of Energy has a calculator that figures the amount of insulation you need for your climate zone: www.ornl.gov/~roofs/Zip/ZipHome.html.)
Also, use a rake, to make sure it’s level across the attic floor.
2 Outlet insulation
Where there’s a break in the thermal envelope of your home, there’s potential for energy loss. One common spot is electrical outlets and switches on outside walls.
Switch off the circuit breaker to these outlets and switches. Remove the faceplate. If you can get the tube from a urethane foam spray can into the wall around the conduit box, shoot some expanding foam in there.
Install foam draft sealers behind the faceplates. They add only a slight amount of insulation, but will improve the overall seal.
3 Can the canister
Recessed ceiling lights are another typical area of energy loss. The most efficient option is to replace your old canister recessed lights with new, efficient sealed models.
Don’t just pour or pack insulation against recessed lights in the attic. This can cause older styles, which were not designed to be insulated, to overheat.
4 Fan plan
Ceiling fans are another place to check. Push the insulation away and caulk the attic floor hole around the wire, then cover it with additional insulation.
5 Trim trick
The next time you’re painting the trim around doors and windows, pry off the decorative molding. You may find a large uninsulated gap between the rough opening and the door or window frame. Apply low-expansion foam in the gap—but use it sparingly because it can deform the frame as it expands.
6 Foam foundation
The sill plate and rim joist are often not insulated. The sill plate is the piece of lumber that rests on the top of the foundation. The rim joist rests on top of the sill plate, and your house walls rest on the rim joist.
Buy kraft paper-faced fiberglass batt insulation and cut it into short lengths to fit against the rim joist between the floor joists.
You will probably see a gap between the top of the foundation and the sill plate in spots. Apply urethane foam insulation from a can all along the sill plate/foundation wall interface.