The Importance Of Venting Your Roof
So many people think a roof is merely shingles applied to the top of their house. When in fact, a properly installed roof is actually a “roofing system” with many more components then just shingles. 
One of the most important components of a “roofing system” is balanced ventilation. This means there is an equal amount of intake and exhaust, allowing your home to continually breath. There is actually a mathematical formula, that quality roofers will use to determine exactly how many square inches of intake and exhaust are needed for the specific home that they are installing a roofing system on.The intake occurs through soffit vents, and the exhaust through a ridge vent. When a balanced ventilation system is properly installed, cooler air is constantly entering the soffits, it rises up pushing warmer air out through the ridge.
Why is balanced ventilation so important? There are several reasons. First of all it will extend the life of the roofing shingles. Additonally, it will reduce cooling costs, by keeping your attic cooler in the summer. Perhaps most importantly, it proper ventallation will help keep moisture out of your attic reducing the risk of unhealthy mold and mildew developing in your attic. Recent research indicates that there are many health risks associated with mold in homes. And if it does develop it is very costly to have removed.
Soffit vents
The attic is a room of the house we don't often think about. It's storage for all the stuff you don't often need, and that's all. But your attic, just like the rest of your house, has specific needs, and without them, it'll suffocate, and possibly choke your gutter too.
Let's start with the most basic problem, which you learned about in high school science: heat rises. Whether you're in the heat all year round, or experience all four seasons, heat goes into your attic -- and unless it's got a place to go, it tends to stay there. This does more than just make your attic stuffy; for example, if you've got a bunch of snow on your it'll form warmer spots on your roof that will melt some, but not all, of that snow and create the much dreaded “ice dam.” In extreme cases, it means you'll spring leaks during the winter, the absolute worst time to start a roofing project. In hotter, more humid climates, it means you've got dark, heat, and moisture; in other words, the perfect recipe for mold. In both cases, water can condense on the underside of your roof and rot it out.
Fortunately, the solution, if not the application, is the same regardless of where you are: vents. Vents allow heat to escape from your attic and keep the attic temperature consistent. But won't that mean cold air comes into your house? Nope: your attic floor is insulated, so venting the attic won't raise your heating bills. All venting does is extend the life of your roof by reducing rot and leaking problems.
Which vents do you install? It varies. If you have an asphalt roof, there will actually be specific requirements spelled out in your warranty that you'll have to comply with: your roofer or contractor should have discussed those with you when replacing the shingles, and they should also be written out. For other kinds of roofs, the manufacturer of the shingles or the roofer may have specific suggestions; it's a good idea to get in touch with them and ask before installing anything.
It will also depend on climate. If you're worried about mold, you'd take a different approach than if you were worried about ice dams. Regardless of your roof, though, the basic requirement is that the vents be close to the attic floor, to allow in cool air. A common tactic is to install soffit vents, long aluminum strips of vents, under your eaves. Cool air flows in and convection takes care of the rest. Soffit vents are especially good for snowy climates, as there's no way for any snow to get in them.
Ridge Vent
Another solution would be ridge vents, which sit atop the peak of your roof and allow the hot air to flow out the top of your roof. Ridge vents are ideal for hotter areas, and can even be paired with soffit vents depending on the situation. They'll need to be installed by a professional, however.
Regardless of your climate and attic, take a look at installing some vents. Your roof – and the rest of your home, including your gutters and gutter covers will thank you.
