When choosing products and materials for a new roof, many homeowners focus mainly on color and what their shingles will look like next to their existing siding or brick.
Naturally, aesthetics and curb appeal are important. But an even more crucial element of your new roof is the attic ventilation system.
If your roofer doesn’t install a well-designed ventilation system through your attic, your home could be subject to problems ranging from moisture damage to irreversibly warped shingles to hazardous mold on your walls and insulation.
Not only can smart choices in ventilation have a positive effect on your wallet (a well-conceived roof replacement can produce an ROI of some 68% when you go to sell), but they can significantly impact the beauty of your home and help you avoid costly repairs.
Here are five key facts you should know about residential attic ventilation systems before installing a new roof.
1. All homes accumulate moisture. The USDA reports a standard U.S. household produces up to six gallons of incidental moisture each day, thanks to sources like showers, dishwashers, washing machines, weather and potted plants. For reasons of health, however, the CDC recommends keeping interior humidity below a standard 50%. If excess dampness isn’t released outdoors through effective attic ventilation, it can promote mold and mildew growth on walls and insulation and/or rise to linger in your attic. In cold weather the excess heat and moisture in your attic can melt the snow on your roof, creating ice dams that can cause damage to the shingles and roof deck.
2. Today’s homes are more airtight. In the past, less-sophisticated residential construction meant interior moisture was able to escape more easily through walls, seams, chimneys, etc. That’s less likely to happen in today’s more energy-efficient homes that are sealed up tight, which means that proper ventilation is more important than ever to help eliminate any trapped moisture.
3. Many of today’s ventilation systems are ineffective. Boxed, slant-back and turbine vents are intermittently installed and often fail to create the necessary 50/50 balance of intake and exhaust. This means less air movement in the attic and ventilation that only happens where those vents are installed. Ridge vents are the only vent type that can be installed in a continuous line along your rooftops to evenly vent across the entire roof and eliminate trapped air. Handy ventilation calculators are available online and can help you determine the ventilation needed for that optimal balance; if your roofer seems unfamiliar with the 50/50 concept, you may wish to seek a more experienced roofer.
4. Ridge vents don’t look like old-fashioned vents. While older vent styles tend to jut out of your rooftop and stand out against shingles or tiles, today’s more modern ridge vents are nearly invisible. That roof accessory choice is one area homeowners seem to overlook the most, and it can make or break the overall beauty of your roof. Today’s ridge vents are a safe choice because they fit with any architectural style and work with a variety of roofing materials including asphalt shingles, cedar shakes, flat tiles, metal and stone-coated steel.
5. Certain vents can be high-maintenance. Static varieties can get clogged by snow, leaves, brush, insects, birds, rodents or other debris, and if they’re mechanically powered they may be prone to electric shortages or wiring issues. Ridge vents, conversely, are self-powered and built with a membrane that prevents rain, snow or debris from sneaking in.