Many building codes now mandate intake and exhaust ventilation for attics. It’s easy to see why. A properly ventilated attic can save energy, eliminate excess moisture, prevent mold, and prevent ice damming in winter. And, by minimizing heat buildup in the attic, proper ventilation can even prolong the life of the roof system.
Many building codes now mandate intake and
exhaust ventilation for attics. It’s easy to see why. A properly ventilated
attic can save energy, eliminate excess moisture, prevent mold, and prevent ice
damming in winter. And, by minimizing heat buildup in the attic, proper
ventilation can even prolong the life of the roof system.
experts agree that a balanced ventilation system - with intake ventilation
meeting or exceeding exhaust ventilation - is ideal. However, in my
neighborhood, a suburb of Detroit, intake ventilation is pretty rare. Most of
the houses were built in the 1950s, and very few of them have overhangs at the
eaves that allow for perforated soffits. With the exception of the newer houses
or houses that have undergone major remodeling projects, there are very few
houses with intake ventilation at the eaves. I should know, because I walk my
dog every day, and, because I work for a roofing magazine, I’m often looking at
the roofs in my neighborhood.
When designing a remodeling project, what
are the best ways to install intake ventilation in houses with no overhangs?
I know of a few products that are designed specifically for these cases,
including DCI products' (www.dciproducts.com)
SmartVent, a tapered, corrugated plastic vent that installs under the shingles,
which can be used for both intake and exhaust ventilation.
recently spoke Steve Henderson of DCI Products, who cautioned that ridge vents
aren’t effective without intake ventilation. “We explain it this way: It’s like
sucking on one end of a straw with your finger over the other end,” he said.
“You need proper intake ventilation, and that’s why my father invented the
According to Henderson, the most popular usage of the
SmartVent is at the lower eaves edge for intake ventilation in cases where there
are no overhangs, but it can also be used for intake and/or exhaust ventilation
for shed walls, dormer peaks, and ridges with wide ridge beams and firewalls.
Let me know how you cope with houses with no overhangs in a reroofing
and remodeling situations in the design stage. Some of my neighbors are planning
additions to their houses.
From the Editor's Desk: Attic Ventilation and Reroofing Projects
By Chris King
Chris King is editor of Roofing Contractor. He can be reached at 248-244-6497.