Insulating Inside & Out
By Owen Whetzel
Put simply: Adding or increasing the amount of attic insulation to your home and, in some areas, adding floor or wall insulation, as well as weatherstripping areas, where cold air enters in the winter and cool air escapes in the summer, offers great potential for energy savings and increased comfort. What's appealing about insulation and weatherstripping is that the pay-back on the cost should be fast.
INSULATION
Look at R-value, when purchasing insulation. R-value measures the effectiveness of an insulation material. The "R" stands for "resistance," the ability of the material to resist the flow of heat. The higher the R-value, the more effective the insulation. However, a sloppy installation can decrease the effectiveness of the insulation, particularly compressing batts of insulation or leaving gaps (other than for attic ventilation or any heat producing device, such as lighting fixtures, furnace flue or vents, exhaust fans, etc.).
You will likely need a minimum total attic insulation of R-38 (you can exceed the minimum, if you wish), but more may be needed, if you live in an area with freezing winter or hot summer temperatures. Floor insulation needs will vary depending upon where you live. Wall insulation is limited by the depth of the wall cavity.
A good place to start gathering information is "Insulation Fact Sheet,"
prepared by the U.S. Department of Energy, Oak Ridge National Laboratory. This site will also allow you to calculate the R-value of insulation needed for attic spaces, wood frame wall cavities, under-floor, basement wall interior, insulative sheathing on empty wall, and adding insulative sheathing to R-11 wall, based on your zip code. (See "Determining the R-Value You Need for an Existing House."
For example, if you know that the attic currently has R-19 insulation (6 1/4" deep) measure the depth of the insulation. If you need to achieve R-38, deduct 19 from 38. The difference tells you, that you need to add insulation with an R-19 value. However, this is only an example. What you should purchase and how much depends upon a number of factors and the climate in the area, where your house is located.
When adding insulating batts, to be placed over existing insulation remember, to buy material without a foil or paper face (the moisture barrier), or you must make slices in the facing material, so that you don't trap moisture between the old and new insulation.
Another option, preferred by some energy experts, is to install plastic encapsulated insulation, as a second layer. Plastic encapsulation not only makes installation easier, but also reduces the negative effects of condensation on insulation. A second layer of insulation is usually laid perpendicular to the joists.
Be certain to follow all of the insulation manufacturer's instructions and warning carefully. Is placing insulation a good do-it-yourself project? Yes and you should be able to see the results of your efforts each time you receive a bill for the cost of heating or air conditioning.
WEATHERSTRIPPING
Gaps, cracks and openings, where cool air enters or warm air escapes, must be sealed. Run your hand along door and window frames; over switch and receptacle plates; along baseboards; access doors to a basement, crawl space or attic; around ceiling and wall-mounted light fixtures; and particularly around anything penetrating through the wall (air conditioner, fireplace, exhaust vent, mail slot, etc.). There's an old rule of thumb, which often proves to be correct. Where you find spider webs, you are likely to find a draft nearby. Weatherstripping, caulk, and insulting foam are the solutions to most of these energy wasters.
Heating and cooling ducts can leak air into an attic or crawl space (beneath the floor), where it does absolutely no good. Check all duct joints and tape them using a heat-resistant tape (common duct tape won't work) or apply duct mastic. Once joints are sealed, wrap insulation around the pipes. Anything you do to keep expensive heat directed where you want it, instead of "floating", away saves energy and money.
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There are many resources for home insulation and weatherstripping information. The utility providing your gas and/or electricity is a good place to start. Here are some other resources:
-- An article worth reading is "Insulation and Air Sealing" on the U.S. Department of Energy's Energy Efficiency and Renewable Energy (EERE) Web site.
- Links to insulating information can be found in "Insulating at a Glance" on the Owens-Corning Fiberglas Technology, Inc. Web site. A printed version of "A Homeowner's Guide to Insulating & Noise Control" is available at no cost by phoning Owens Corning, (800) GET-PINK (800-438-7465) or may be requested through the Web site.
-- "136 Best Ways to Save on Your Home Energy," by the editors of Sunset Books (Sunset Books).
-- "Quick Guide: Insulation and Ventilation," by the editors of Creative Homeowner (Creative Homeowner)
-- "Insulate and Weatherize: Expert Advice from Start to Finish," by Bruce Harley (The Taunton Press)
-- "Popular Mechanics Weatherproofing and Insulation," by Albert Jackson and David Day (Hearst Books)
-- Check with a library for other books on insulation, as well as magazine articles. A periodical or Web search using the keywords "home insulation," "weatherization," "weatherstripping," and "home energy savings" may provide you with some of the most current information.
-- A good resource for answers to specific technical home insulation questions is the California Energy Commission, 1516 Ninth St. Sacramento 95814. Phone: (916) 654-4287 (this is not a toll-free phone number).