Ventilation
Good Roof Ventilation Planning Makes
a Difference!
 On almost every roofing job we install
some type of ventilation.
Have you ever been in your attic during
the summer? The heat is about enough to
make you not want to go into your attic.
Shingles fail due to poor attic venting.
Nearly 200 F heat can build up on a hot
day in a poorly vented attic. That heat
can slip past the sheathing (decking) and
ruin fiberglass shingles. Heat builds up
in the attic space which should cool off
at night if the attic is properly ventilated.
Modern home construction methods result
in better insulated and tighter homes,
which save the homeowner money on energy
bills, but makes the need for a well-ventilated
attic even more important. Attic ventilation
is necessary to prevent moisture problems,
to prevent heat build-up, to reduce heating
and cooling costs and to prevent ice dams.
The benefit of proper ventilation for the
homeowner are a cooler attic in the summer,
a dryer attic in the winter and protection
of the structural integrity of the home
from moisture damage.
According to the National
Roofing Contractors Association (NRCA),
guidelines for roof ventilation have
been established by several organizations. The
American Society of Heating and Refrigeration
Engineers (ASHRE) guidelines calls
for a ratio of 1:150 – that is
one square foot of net free vent area
(NFVA) for every 150 square feet of ceiling
area below the roof. Using that ratio,
a 1,500 square foot area would require
10 square feet of ventilated area. The
Building Officers Code Association (BOCA)
also supports the 1:150 ratio. If the
structure has a vapor retarder, the ratio
can be reduced to 1:300. Most shingle
manufacturers make roof ventilation a
prerequisite to warranting of the products.
Types of Ventilation
Exhaust
Vents: roof louvers, gable
louvers, turbines, ridgeline and power
vents |
Intake
Vents: soffit vents |
Low-Profile
Vents: turtle type |
Ventilation 101 – To Educate the
Homeowner
Your home should have a ventilation system
based on your attic size. The intake vents,
such as soffit vents, will allow for the
air to come in, and then the exhaust vents,
such as gable or ridge vents, will allow
for the hot air to escape. Therefore, leaving
your attic cooler. Then with a combination
of exhaust and intake vents this allows
fresh air to circulate thru the attic. |
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to thank you guys for working with
us and thank you for the quick job
you did. We are very pleased
with the outcome and will recommend
your company to anyone needing any
roofing."
-- Dallas, TX
"Thanks – really
looks good. I like the black
turbines."
-- Irving, TX
"On behalf of
the church, I want to thank you for
this special and dedicated attention
to making sure that we do not have
any further water damage.
We sincerely appreciate
your professionalism, your quick response
to our needs, and the thorough and
responsible way in which you completed
our needed work."
-- Dallas, TX
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