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Weatherization

Fact: Air movement within and through houses is commonly misunderstood. While some contractors swear that houses "need to breathe" and refuse to make any effort to make shells airtight, others remain unconvinced that controlled ventilation is needed in tight houses. You can:

  • Cut your energy bill 10%.

  • Increase R-value performance of insulation.

  • Avoid damage to building insulation and structural materials from water vapor carried into wall and ceiling cavities by uncontrolled air movement.

  • Identify and address indoor air quality and safety concerns.

Best Features: If any combustion appliances exist, back draft/spillage and draft testing should be performed before and after any weatherization (air sealing) is undertaken to identify safety concerns and indoor air quality issues. Then pay careful attention to details like the selection of materials, surface preparation for sealant, fastening, durability, and interaction with insulation.

  • Seal windows, ceilings, and foundations with urethane or silicone sealant or caulk.

  • Choose weather-stripping that will stay flexible under extreme cold conditions.

  • Apply duct mastic or rolled foil duct sealer in your ducts.

  • Consider aluminum or galvanized steel flashing and high-temperature sealant for work near your chimneys.

  • Select dense-blown cellulose insulation to seal hard-to-reach areas.

Save Money: The air leakage in a typical U.S. home is equivalent to leaving a window wide open, resulting in a constant drain of energy and money. Most leaks are actually a series of leaks, and if the air is stopped at the easiest spot, it does not need to be stopped elsewhere. Stop leaks that can be done safely and cost effectively using these ideas:

  • Seal openings in the attic floor.

  • Consider energy efficient replacement windows.

  • Use a plastic sheet to seal a window or door that is not opened often.

  • Caulk gaps around the frames and weather-strip the sashes.

  • Plug the gaps around pipes with grouts and sealants.

  • Weather-strip the entire circumference of the window or doorjamb with one continuous strip.

  • Seal around electrical outlets and switches.

Find It: The caulking and routine weather-stripping of windows and doors that formed the basis of traditional air sealing are used much less extensively today, as workers have found that more air can be stopped elsewhere for less money (and longer lifetime).

  • The best opportunities for reducing overall leakage are often found at the top and the bottom of the house. These areas experience pressures from warm air rising. They also tend to have problems other than heat loss. Leaks at the top of the building, where air usually goes out, often cause condensation problems. Leaks at the bottom can carry moisture, radon, or whatever else is in the soil gas, into the house.

  • Another reason to look at the top and bottom is that the rough areas bordering the living space tend to have large holes that can be fixed relatively cheaply.

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