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Straight Talk Articles

Is Your Attic Haunted by Lack of Insulation?
October, 2016

Dear Pat: Winter is coming and I am wondering if more insulation could help keep my heating bill down. Where should I look first to add more? – Loreen

Dear Loreen: When you go outside in the winter without a hat and coat, you will feel much colder, much faster. Similarly, when your home is not properly sealed and insulated, cold air sneaks in and heat escapes, making your heating system work harder and your home less comfortable. Sealing and insulating your home to efficient levels can cut your heating and cooling costs by an average of 15 percent, and sometimes much more—all while making you more comfortable in your home.

Your attic is one of the first places you should consider insulating since it is usually accessible and easy to inspect for air leaks and insulation levels. Additionally, most homes do not have enough attic insulation: insulation standards for new homes increased in 2012, and many homes built before then do not have the current recommended amount of attic insulation.

Insulation is graded by its “R-value” – the higher the R-value, the greater the insulating power. If you live in a mild climate, your attic should have at least R-38, or about 13-14 inches of insulation. If you live in a colder climate, R-49 is the minimum recommendation, or about 16-18 inches of insulation. More may be needed, depending on your home and exact climate.

How can you tell if your attic does not have enough insulation? As a general rule, if you go into your attic and you can see the ceiling joists on the attic floor, there is not enough insulation. Hiring a trained energy auditor is the best way to diagnose shortcomings with insulation or any other energy-related issue. Check with your co-op to see if they offer energy audits or can refer you to an auditor in your area. Your co-op may also offer a rebate for adding attic insulation.

Once you have determined that you need more insulation in your attic, there are a few things do before laying down additional insulation:

  • If you currently store things like holiday ornaments in your attic, see if there is another suitable storage place in your home. If you must use your attic for storage, build a platform high enough to allow installation of the recommended level of insulation.

  • If you live in an older home, you should check your attic’s electric wiring. Is the insulation around the wires degrading? Do you have knob and tube wiring? In either case, you will likely need to replace the wiring before proceeding.

 

You will then need to decide who will do the insulation work. If you want to DIY the work, you will need to do some homework.—installing insulation is messy, can be dangerous, and requires special equipment. Fortunately, there are many experienced insulation contractors. You should discuss a few things with the insulator before you agree to hire them:

  • Be sure that you or your contractor seals any air leaks, such as around furnace flues, and around any exposed air ducts in the attic. Air leaks can bring warm, moist air from your home into the attic, which can reduce the insulation value and create mold.

  • Pay particular attention to your attic door or hatch. “This entry point is a significant contributor to heat loss and gain in the home,” shared Ken Maleski, the residential advisor at Central Electric Cooperative in Pennsylvania.

  • If you have existing attic insulation, it is usually not necessary to remove it unless it is wet, moldy, or contains animal waste.

  • Make sure that there is sufficient ventilation in the attic. Warmth and moisture can build up in an improperly ventilated attic, which can lead to roof problems such as roof rot or ice dams.

 

There are two types of insulation that you could put on your attic floor: batt/roll or blown-in/loose fill. Blown-in insulation needs special equipment to install, but it fills the space better than batt insulation, which can leave gaps and voids without careful cutting and placement around ceiling joists, vents, and other attic impediments.

Insulation is most commonly made from fiberglass, cellulose, or mineral wool. Many energy advisors, such as Maleski, recommend blown-in cellulose insulation due to its superior coverage, high R-value, and air sealing abilities—it has an added benefit that it is treated with boric acid, which acts as a fire retardant and insect repellent. However, your energy auditor or insulation contractor can help determine what type and material of insulation would work best in your home.

This column is from the October issue of Straight Talk, which is a service of the National Rural Electric Cooperative Association to its member co-ops.  Straight Talk is distributed by electric co-ops around the country as part of a monthly print publication or on co-op websites.

For more information about attic insulation, see this page with more resources.

Blown-in insulation can fill spaces better than batt insulation, but requires special equipment; this equipment can sometime be rented at home improvement stores. Photo Credit: Weatherization Assistance Project.