Introduction - Getting Started - Materials Checklist - Plug Holes - Seal Furnace Flues - Foam or Caulk - Complete Job - Attic Duct Sealing - Recessed Can Lights - Sealing Basement
Even though most of the gaps spilling warm air into your attic are buried under insulation, you might see evidence of these gaps. Look for areas where the insulation is darkened (see photo 8). This is the result of filtering dusty air from the house. In cold weather, you may also see frosty areas in the insulation caused by warm, moist air condensing and then freezing as it hits the cold attic air. In warmer weather, you'll find water staining in these same areas. Although the insulation is dirty, it is still okay to use. There's no need to remove and replace. After sealing the areas, just push the insulation back into place. If you have blown insulation, a small rake can be helpful to level it back into place.
8. Find Attic Bypasses
Check for gaps in your attic that facilitate air movement by checking for diry insulation. Seal gaps with caulk or expanding foam. When complete and dry, push the insulation back into place.
Seal Small Gaps
Use expanding foam and caulk to seal the openings around plumbing vent pipes and electrical wires (see photos 9 and 10). Be sure to wear gloves and be careful not to get expanding foam on your clothes, as the foam is very sticky and nearly impossible to remove once it sets.When the foam or caulk is dry, cover the area again with insulation.
9. Fill Holes with Caulk
Fill wiring and plumbing holes with expanding foam. Caulk around electrical junction boxes and fill holes in box with caulk.
10. Stuff Gaps with Insulation
If the space around your plumbing pipe is wider than 3 in., you may need to stuff some fiberglass insulation into the space to serve as a backer for the expanding foam. Once the fiberglass insulation is in place, follow the directions on the can to foam the space around the pipe.
Approved for publishing by the EPA
. Questions of a Do It Yourself nature should be submitted to our "