Home Air Sealing
Why should you seal air leaks in your home?
- Save on your heating and cooling costs
- Improve your comfort
- Have control over indoor air quality
- Prevent Ice Dams and moisture damage
- keep moisture out of walls and attics
- avoid paint failure
- prevent frozen pipes
Can your home be too tight?
- Short Answer: NO
- But, they can be under ventilated
- A tight building is easier and cheaper to heat, cool, and
ventilate
- A tight building gives you better control over indoor air quality
- A well insulated, tight shell will make up for shortcomings in the
HVAC distribution a lot better than trying to make the
distribution system make up for a leaky shell
Isn't adding insulation enough to improve
comfort and save energy?
- Fiberglass Insulation
does not stop air flow
- Loose blown
cellulose does not
stop air flow
- If air moves through
insulation it is not
insulating--it is just
an air filter
- Some types of
insulation are also
good air barriers.
Rigid or spray foam
may be helpful in
certain areas
This dirty insulation is a sure sign
of air flow and wasted heat
Which leaks should be sealed?
- All leaks play a part in the problem, so seal everything
- Because of the "chimney effect" the upper floor leaks are outward. Sealing the attic and
top floor leaks stops warm moist air from leaking into walls and attics, reducing heat loss
AND moisture damage
- On lower levels, cold, dry air tends to leak inward. Sealing these leaks prevents heat
loss and slows the overall leakage rate.
- With a tight building shell, an exhaust fan can depressurize the building enough so that
almost all air leakage is inward, thus minimizing moisture damage.
The following pictures show a few of the attic areas we
commonly find needing sealing, even in brand new
homes
This utility chase goes from the basement
to the attic
All wiring for plugs and switches make for
holes into the attic
The top plates of most walls leak air
into the attic
Vent pipes for the drain system almost always
have large air leaks
Typical large gaps around chimney
can extend from basement into the
attic
Chimney gap after sealing with flashing
