Help Your House Vent

While growing up in Upstate New York, I would accompany my grandpa on one of the most gravely critical missions a 6 year old could undertake: chasing squirrels out of the attic. Every winter, they’d chew their way back inside the three story historic structure built in 1909. So he’d march up, more determined every year, to plug, seal, block and fill every nook and cranny. Once, he was so mad that he actually patched a hole with asphalt. In terms of animal management, this seemed like a good strategy. Unfortunately, it wasn’t a good air management strategy—and the hot, moist air that was trapped during the summer months caused major energy and mold problems over time.

If you’ve ever hauled anything up to your own attic on a warm summer day, then you know just how HOT it can get. With the sun shining down on dark shingles, it can start to feel like an oven. Add to that the moisture that rises from everyday activities—like breathing or cooking or taking a hot shower—and you have a recipe for all sorts of mold, mildew and rust. Yuck.

Depending on building codes, the area where you live and the age of your home, your house was probably built with a ventilation system in the attic. In most cases, this system is a passive one, made up of a few styles of vents that are positioned to provide constant air exchange—aka—when stale, hot or moist air is vented out so new, fresh air can replace it. It can seem counter-intuitive that venting is an important way to save energy when we hear so many virtues of insulation and caulk. But venting, especially in the attic, can help:

• Extend the lifespan of your roof shingles by keeping the underside of the roof cooler in very hot weather.
• Reduce the burden on your air conditioner by allowing hot air in the attic to escape to the outdoors.
• Prevent moisture build up that can fuel the growth of mold, mildew and rust that can cause expensive structural damage, and even irritate the systems of sensitive family members.

The really good news is that in most cases, there isn’t much you need to do. Your system was designed to work all by itself all year long for free—and how many things in life can you say that about? What you do need to know is how to recognize the early warning signs of venting problems before they cause expensive damage. Here are a few things you should be on the lookout for:

• During cold winter months, check the underside of your roof and rafters for frost. Frost is a signal that too much moisture is trapped in the attic; it just condensed and froze, making it easier to detect.
• Look for any water stains, dark or blackened wood, mold, mildew or rot.
• Examine all exposed metal, including brackets, nails and screws for signs of rust.
• Survey your insulation. Is any of it matted or compacted in a specific area? This can be a sign of a roof leak.

So grab a flashlight (and maybe a broom, if you suspect a squirrel or two) and head up to inspect your attic this weekend. It should take less than 10 minutes and give you peace of mind for the rest of the year. In the unlikely event you discover a warning signal—it’ll be less expensive in the long run to call a professional right away.

Have you had a venting problem in the past? Share your story in the comments!