When you're planning a new roof, it's all too easy to get caught up in details like shingle type and color. Yet this leaves you overlooking many other important details that homeowners rarely understand the importance of, such as the vents used to move air through the roof. Attic ventilation can be the difference between a huge summer cooling bill and a comfortable home without the A/C on at all. Find out where vents should be located on a new roof for optimal air flow in all four seasons.
The Importance of Vents
Roofs work best with a steady flow of air both under and over them. The right combination of intake and outlet vents creates a breeze that prevents hot air from accumulating in the summer and cools off the attic in the winter. You might think that a cool roof in the last thing you want when it's cold, but a warm roof causes snow and ice on the roof to melt and seep under the shingles. Air flow is also important to prevent mold and mildew growth, as well as rot. Of course, vents that are placed too far apart or too far close together fail to work properly, and improper location can also suck exhaust or moisture into the attic.
The Concept of Rising Heat
Everyone knows that heat rises, but it's often forgotten when it comes to placing roof vents. Secondary pop-vents installed on the sides of a sloping roof simply can't exhaust hot or warm air as well as a ridge vent, which is an opening installed at the very peak of the roof. Similarly, installing the inlet vents as low as possible, usually on the soffits when possible, increases the amount of rise available as the air travels to the outlet vents. Therefore, you want to keep vents both as low and high as possible to get as much air moving as possible without having to rely on powered vents with fans in them.
The Common Obstacles in the Attic
Of course, you can only rely on this natural heat-created breeze when air flows without restriction or obstacle between the low vents and the high ones. One misplaced box of holiday decorations or shifted piece of insulation can cut off a large amount of air flow and leave your attic hotter than usual. Of course, the attic is also full of mandatory obstacles that can make placing vents tricky. For example, cutting a vent opening where duct work or electrical wiring is located will lead to a blocked vent and damaged ducts or wires. Vents obviously can't be placed where the rafters are either.
Roofs with complex valley constructions have limited ridge space, so these buildings tend to have extra vents at the peaks of the gables as well to increase vertical flow. Pyramid and hip roofs have only a small ridge that isn't big enough to vent a whole attic, but the lack of flat ends provides no gable venting opportunities either. In these cases, pop-up vents as high as possible on the sides of the slopes are the only option.
The Wrong Intake of Fresh Air
Finally, putting your intake vents in the wrong spots will cause potentially dangerous air to enter your attic. Anything under the soffits and within 10 to 15 feet of each vent can affect the air going inside your home. Many vents are placed over driveways where cars sit and release exhaust, the exhaust vents for furnaces and other combustion devices, and sources of moisture like dryer vents. It's better to skip a vent or two or relocate them whenever possible than to draw in the wrong kind of ventilation air. Concerned about how your roof is vented? Call us here at Hayco Roofing to schedule a quick inspection before more serious problems develop.