Exclusive Buyer Realty

Do you see dirt lines on carpets under doors that remain closed much of the time?

If you see dirt lines on the carpets under the doors, there is, more than likely, a pressure difference between rooms, and the carpet is filtering out dust from the air flowing under the door. Such pressure differences usually increase infiltration and exfiltration– sometimes dramatically. If you see dirt lines at 4′ intervals in the carpet, the carpet filtration is between floors of the house at the sub-flooring joints, again with energy consequences. If the lines are only found across part of the room, there is typically a pan-duct serving the furnace (pan ducts almost always are energy disasters). Dirty lines at the edges of carpet indicate air flowing to and from the exterior or from the level below. Almost all houses admit far too much air into the house when the wind blows. Studies show that many households can save far more energy by tightening the house than by adding additional insulation; and houses that are drafty suffer from very dry air in the winter. For example, if the relative humidity of outdoor air is a humid 70% when the temperature is a cold 10 F, it will be a dry 6% when warmed to room temperature (70 F).

Consider tightening your house to improve the energy efficiency. For every cubic foot of air that comes in through cracks at a temperature equal to the outdoor air, one cubic foot of air at room temperature is escaping; and in most cases, you will not be able to feel the air that is escaping unless the wind changes direction. You may be able to find leaks from the house enclosure into the attic by looking for gray-colored areas in any fiberglass or other light-colored insulation. The discoloring is caused by dust being filtered out by the insulation as dusty air passes through it. If possible, remove insulation from over partitions to search for penetrations. The top plate on almost all partitions eventually shrinks, leaving a gap. Closing this gap with caulk is extremely important. Use a good dust mask, gloves, and take all precautions to avoid falling through to the room below. Special “fire-safing” fiberglass rather than the ordinary fiberglass should be used to seal large openings. Pack the fiberglass tightly into the space (remember to use a dust mask). Foaming insulation from a can or acoustical sealant may also work. But beware of packing anything around a furnace or woodstove vent (metal plates usually are used instead). You should seek assistance from a heating contractor for insulating around any vents– preferably one who is a holder of a mechanical license.

Here is a list of other areas most likely to be causing air infiltration concerns:

1. Caulk and insulate around the sill at the top of the basement foundation wall if the basement finish permits.
2. Apply weather-stripping around the perimeter of the access doors to the attic.
3. Cover the attic access door with batt or foam insulation.
4. Stuff fiberglass insulation around the edge of the fireplace damper plate (remove it before starting a fire). If the fireplace is rarely used, stuff fiberglass filled polyethylene-bag “pillows” into the fireplace flue.
5. Close all openings around chimney, plumbing pipes, ducts, electrical wiring, etc., that run from the basement or interior to attic.
6. Insulate above built-in kitchen cabinets and valences in one story houses that open to the attic.
7. Insulate above shower surrounds open to the attic.
8. Replace the dryer vent discharge device on the exterior wall of your house, if it is the cheap type with a flap in it, with a vent hood that leaks little air when not in use.
9. Seal outside wall switches and electrical receptacles with special gaskets from building centers.
10. Caulk around ceiling light fixtures. Recessed ceiling lights on the top floor work like a chimney to suck out conditioned air, so replace them with fixtures that comply with the ASTM E283 standard. All of these are also rated “IC” (insulation contact), so that you won’t have to worry much about fire. Others rated “IC” can be sealed by building an insulated box around them and sealing the box to the attic floor.
11. Stairs with sloping ceilings in balloon framing are energy disasters even if tented over with fiberglass batts. Insulate and seal the wall cavities so that air cannot flow from the foundation or interior into the attic.
12. Finished rooms under gable roofs are energy losers and so are garrison soffits. Contact a professional insulator.

Studies have shown that openings are the worst infiltration offenders in the typical house. In addition to reducing heat loss, closing these openings will prevent fire from spreading rapidly throughout the house and will reduce the amount of moisture. After you tighten your house, you can get professional infiltration testing to see how well you’ve done. Ask your utility company for referrals to a specialist who can do a blower door test. The specialist may even help you pinpoint leaks you missed.

Chet Riley is the Owner/Proprietor of CENTENNIAL Home Inspections. For any questions regarding home inspections, please call Chet at 585-293-2278. Or e-mail him at criley1@rochester.rr.com. Further information can be obtained at http://www.centennialhomeinspections.com/.