Insulating an Attic

If you're looking for your next home improvement project and want to do something sensible that has immediate returns on your investment, consider installing or upgrading your attic insulation. More than any other place in the home, quality insulation in the attic promises to give you the most benefits. Studies show that most homes will pay for the cost of installing attic insulation within 3-6 years. It may not sound sexy, but attic insulation is one of best functional home improvement projects out there.

Insulating an Attic from the Heat and the Cold
More heat is lost through poor attic insulation than from any other place in your home. If you think about it, it makes sense. Heat rises and when it rises through your home, it ends up leaking through the attic. On the other hand, many attics are the farthest place in the home from the central air conditioning and can be the hottest room in the house. Thus, attics need to be insulated from the heat and the cold. Whether you're trying to improve the energy-efficiency of your home or make your attic space comfortable, attic insulation is almost universally a great idea.

Attic Insulation Installation
Blown cellulose or fiberglass insulation tend to be the insulating materials of choice in most areas of the home, and the attic is no different. This especially holds true when laying new insulation over the old. If you have an older home, you'll need to make sure there's no asbestos in your old attic insulation. (If in doubt about asbestos, consult with an insulation contractor for advice.)

Blown insulation generally covers better in an existing house and is more economical—just be sure you get quotes by R-value—not in inches, as that will vary among many different products. Also, be sure your quotes include the minimum depth in inches and that the number of bags to be used match the manufacturer's specifications.

Naturally, the cost of installing attic insulation varies greatly depending on your situation. Current insulating values, desired insulating values, size of your home, attic accessibility, and other local factors will all influence the total cost. Installing attic insulation can be as cheap as a couple hundred dollars or expensive as several thousand. Be sure to get multiple, clearly-stated, written estimates to gauge how expensive the project will be.

Vapor Barriers and Attic Ventilation
Attics and roofs are much more complicated than simply sheltering your home's interior from the harsh elements of the weather. Along with proper insulating qualities, a well-constructed attic must keep moisture from forming on your roof but allow air to circulate, bringing in fresh outside air. Attic insulation should include a vapor barrier between the insulation and the interior surface to prevent condensation from infiltrating your roof. Condensation can ruin the insulation itself, cause rot in your roof framing, and blister paint.

The hot air that accumulates in your attic must be allowed to vent to keep your air conditioner from over-working. In the winter, temperature differences can cause the formation of ice dams that threaten serious damage to your roof. Covering existing attic vents with insulation can be a catastrophic mistake. If your attic doesn't already have vents, they may need to be added with installing the attic insulation.