The Importance of Attic Insulation

It’s hard to imagine life in the heat of the summer without the cool refuge that air conditioning provides. An air conditioner alone can’t keep your home cool, however — your unit needs help from a host of silent partners, and none so important as your attic insulation. Although you rarely see it or think about it, your attic insulation is a valuable part of your home cooling system.

The right amount of attic insulation can help keep your home cool through the summer and it keeps your air conditioning unit from running constantly. When your air conditioner runs less, you save energy and your air conditioner lives longer, saving you even more in maintenance and repairs.

Types of Attic Insulation

No matter what type of insulation you prefer, they all work essentially the same way. The air pockets that are trapped inside insulating materials act as thermal barriers, preventing any mingling of the air between the living area and the attic. There are several types of attic insulation to choose from, including:

Batt insulation. If you’ve been in a home improvement store and you found yourself staring at big, fluffy rolls of insulation, you were eyeballing batt insulation. It comes pre-cut in a variety of widths, with and without paper backing, for nearly any application. Batt insulation isn’t too complicated for a typical homeowner to install, but it is labor intensive.

Blown insulation. Also known as loose-fill insulation, this insulation is made from shredded or pelleted materials including fiberglass and cellulose. It’s installed using a air-powered blower. This type of insulation is great for oddly shaped attics, or attic spaces with difficult-to-access areas. You can blow it as deep as you want to in order to get the R-value you need.

Expanding foam insulation. When you’re looking to fill cracks between your attic and the outside world, there’s nothing better than expanding foam insulation. It’s not as dense as other types of insulation, but it’s much better than caulk for filling gaps that allow outside air to sneak in.

Foam board insulation. Although foam board insulation isn’t ideal for whole attic insulation, it’s great for sealing openings like attic hatches or for sheathing attic walls. It’s the most expensive insulation available, but if you opt for it, you’ll only need it in a few spots, so spring for the best foam board you can afford.

How Much Attic Insulation is Enough?

Homeowners often wonder if they have enough insulation in their attics. How much insulation you need is dictated by many variables, including your local climate and how well your home is shaded and ventilated. A well-shaded home with good attic air movement can often get away with less insulation than a home that’s poorly ventilated and exposed to the heat of the summer.

In general, homes located in areas with hot summers will stay coolest with insulation with R-values between 38 and 60. In regular terms, that means you need at least 12 inches of batt insulation, or a minimum 10 to 17 inches of loose fill (depending on the type of loose fill you use), to get to R-38.

You can improve your energy efficiency even more by adding attic vents to increase air circulation, installing a radiant barrier in your attic to deflect the summer’s heat, and sealing cracks that allow hot attic air to leak into your home. Little improvements can go a long way in beefing up your attic’s defenses against the hot summer.

Before this summer’s heat gets the best of you, check your attic’s insulation. If you have less than 10 inches, there’s room for more — because sufficient attic insulation is one of the most important pieces in the home cooling puzzle.