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Sealing

Question: This past winter when we had torrential rain and gusty wind I sensed a draft in my house although the heat was on and a fire was going in the living room fire place. What would cause this to happen and what can I do about it?

Answer: The problem is probably improper sealing. Air leakage can come from many parts of a house. Although most commonly thought of as the entry points of air only 10-15% is through windows and doors. The greatest areas of leakage are around the top of the foundation and around penetrations into the attic.

There are many things you can do to reduce air leakage in your home. However, keep in mind that a professional with the proper training and equipment is best suited to pinpoint it and to identify and deal with combustion safety problems. The use of a blower door, a large powerful variable-speed fan mounted in a doorway that blows air into (pressurizes) or sucks air out of (depressurizes) a building used for testing, can make locating and sealing air leaks much easier.

In addition to warmth, a home sealed and insulated in the right manner can provide other benefits. It’s
possible to save 30 – 40% on your heating bill. The best approach is to plan a comprehensive attack, investing first in the items which give you the greatest savings for the least investment. Your home should be sealed and then insulated.

For example, you mentioned that you have a fireplace. Is the damper closed tightly and does it have a top seal? Are either a tight fitting glass door and/or a decorative insulated cover installed? Is there outside air provided for combustion?

Stopping air leakage is also important for protecting your home from the damaging effects of moisture. Air, leaking into walls from the interior of the home, carries humidity with it. This moisture hits a cold surface and condenses, causing the insulation and surrounding wood to get wet and eventually leading to mold and mildew causing wood rot, structural damage, peeling paint, and a variety of health problems.

A two-pronged approach is needed for ultimate efficiency. Sealing up the outside of your home without sealing up the inside, traps moisture in your walls and can lead to mold growth and wood rot. Sealing up your home without providing outside air for combustion in gas furnaces, water heaters, and wood burning fireplaces can lead to air quality problems and could even allow carbon monoxide to build up.