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.

Industry 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.

I 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 SmartVent.”

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.