An
essential place for home insulation is the outer walls. Combined with your floor and roof, exterior walls could be causing over 50 percent of your energy loss. (The scientific term for that is a "huge mega-chunk.") Sealing air leaks and properly adding insulation to your home's envelope—its outer surfaces like walls, floor, and roof—can effectively reduce those energy losses. It's wise to add home insulation to exterior walls in particular, because of their large area.
Adding sheathing insulation is wise if you're already planning to replace siding. Consider nonstructural foam sheathing, which goes underneath it. The rigid foam panels are relatively easy to work with, especially compared to teenagers. Nonstructural sheathing with a home insulation value (R-value) of around R-5 decreases a home's heating and cooling needs and helps protect against moisture buildup inside exterior walls.
Wall-cavity insulation works in conjunction with nonstructural exterior sheathing. Not sure if the cavities of your exterior walls have insulation? Here's your mission: Remove an outlet cover or make small holes in a discreet area, like the inside of a cabinet. If your home doesn't currently have wall-cavity insulation, insulate that area before adding nonstructural sheathing. Blown-in insulation does not require the walls to be torn open, which may be good news to certain members of the family (you know who you are).
1. Determine how much exterior wall space you have, and then purchase the necessary amount of insulation and supplies.
2. Cut the panels to fit.
3. Nail the panels to the studs, in accordance with product guidelines for nail spacing.
4. Use caulk to seal to the top plate and band joist.
5. Tape the seams.
Insulate walls to the correct overall R-value. The ideal R-value for insulating walls varies according to your climate. In general, walls should be insulated to at least R-11.
Compare contractors' bids for the same R-value. When comparing contractors' bids, make sure they are for the same R-value, not just the same number of inches.
Install correctly. Make sure that the insulation is free of gaps. When driving nails, be sure to avoid crushing the foam.
Consider applying the sheathing over the old siding instead of removing the old siding. Ask a pro whether this is feasible for your home.