Why Should I Care About My Attic's Ventilation?

Crawling through my aunt’s attic as a child I told my brother to wait while I proceeded on my hands and knees. “Wait, I’ll go first, it might be dangerous.” Then I fell eight feet to the concrete floor through the sheet-rock and broke my wrist. Yes, it was dangerous. That dark, dank space above our heads certainly has a mystery and danger that even a child can recognize. But even as an adult, there are many dangers you may not suspect or be aware of. 

Your attic is an environment of its own, designed by architects and builders. Modified territorially to fit the climate and modified by time as we learn new technology. Although most of us choose to ignore the space we live under, I have chosen your attic as my life’s profession and passion. 

You see, I’m a roofing contractor that makes his living tearing off the roof of your most prized and valuable asset – your home. People ask me if I tear roofs off in the winter. I tell them, “Yes, I still have bills in the winter.” Joking aside, tough winter climates and conditions are the true test of your roofing system. As a contractor, I can tell you winter exposes and exacerbates ANY weakness your system might have. Your attic space is an essential part of your roofing system. 

Warranty issues are problems for both the contractor and the homeowner. Our goal as a contractor is to give the homeowner a roofing system that will last the promised life expectancy with zero problems. It is a homeowner’s responsibility to maintain their roof system. These maintenance responsibilities can include simple things such as cleaning, caulking, and removal of moss and debris. Moving air through your attic space is also an essential part of maintaining your roof. 

A warranty problem creates stress for the homeowner and a trip to the home by the contractor. Over the years many of the issues I have faced as a contractor are due to moisture and heat. Winter moisture and summer heat are two of the largest contributing factors to premature aging of your roof and your entire building envelope. 

The barrier between the outside elements and your inside comfort is your ATTIC!

So why should you care about what happens in your attic?

Modern homes are designed for proper venting. Your modern home is designed to uniformly pull fresh air IN at the eaves and exhaust bad air OUT the openings at the top of your roof. That means in the summer, cool air in and hot air out. In the winter, cool air in and moist air out. 

Your home’s attic system moves air by convection: hot air rises pulling air into the vents located low on your roof and exhausting it out the vent system located high on your roof. While this system works to remove air in the summer many times, because of the lack of convection, it does not work in the winter. 

There are several ways that roofing contractors use to vent your roof, and in most cases these venting systems comply with the local building code. The two most common venting systems are the ridge vent style of venting and the can vent style of venting. Many manufactures are now recommending the ridge vent style as it uniformly vents your home from the highest point on the roof, while also venting the entirety of the ridge area. Regardless of the age of your home, a roofing contractor can help you design a system that works for your home and properly vents hot summer air and moist winter air. 

The key to good ventilation is uniform air movement from eave-to-ridge across the entirety of your attic space!

Open your attic hatch in your home and, depending on what type and if you have insulation, you can usually expect something to fall from that space and make a mess. Insulation loft is an essential element to the effectiveness of insulation and, depending on your area, you will have codes to tell you how much you need. Moisture destroys the effectiveness of this insulation. In fact, a percent and a half of moisture in your insulation reduces the effective R-value of your insulation by 33%. Moisture from breathing, living, cooking, laundry, and showering all transfer through your living space into your attic and must go somewhere. Most often, its first stop is your insulation. Combine cold atmospheric conditions with hot air coming from your living space and you attain condensation. As a contractor, I have literally seen water dripping from the interior boards and roof decking in winter conditions. Many of the warranty issues I have dealt with over the years come from condensation dripping onto insulation and then traveling through to become visible interior stains. YUK! No one likes stains, nor the resulting mold. Mold spores produce allergens which can and will cause health problems.

Non-vented, moist air in the attic can also lead to wood rot, warped decking and certainly added expense to any roofing project. Not to mention the degradation to the building envelope itself. Try selling your home and hiring an inspector only to find out you have thousands of dollars in wood replacement costs before you can even list your property. 

Proper venting is cheap insurance and by spending a few dollars up front you can have a healthy, fresh, moisture-free attic. Keeping moisture out of your insulation alone can offer you immediate savings to your heating bill putting money directly back into your pocket. 

Your composition roof surface is generally a mat material base with asphalt impregnated into it and a granular surface added for color and protection. This asphalt surface retains heat. UV sun rays and heat are one of the many conditions that decrease roof life expectancy. Removing heat is key to maintaining and preserving your roof. 

On a 90 degree, sunny day, your roof surface can reach beyond 170 and your attic space can reach temperatures of over 150 degrees. That is literally like having an oven over your head. 

Have you ever wondered why your home is so hot in the evening hours after the hot sun has gone down? Your building, roof, and insulation loads up with heat. As this heat unloads it transfers that loaded heat into your living space. Heat can transfer down into your living space, decreasing your interior comfort and increasing your cooling costs. Uniformly removing this heat is essential for the protection of your home’s building envelope and the protection of the roof surface itself. 

Power activating your existing vent system through the use of several small, solar-powered fans can be a solution to your heat and moisture problems emanating from your attic space. By managing attic air flow now, you can benefit through increased comfort and health not to mention the energy savings. The future of attic ventilation is here now.


About the Author

Dan Rheaume is the owner of Raynproof Roofing, a residential roofing company in Seattle, Washington since 1986. In 2009, he started the Solar Blaster Corporation and is the nation’s leading expert in the use of multiple, small, solar-powered fans that will revolutionize the way homeowners ventilate their roofs.