Your roof has many enemies. Some of them are obvious and visible: storms, wind, hail, and severe wind events like tornados and hurricanes are among these obvious problems.
Others are hidden from sight, or you can see them but underestimate the damage they do. This includes the sun, and the heat that gets trapped in your attic and soffits.
While the obvious enemies are easily seen and it is clear when they need to be addressed, it takes a roofing expert to protect your roof from the danger of excess heat. The swelling and shrinking that comes from extreme heat swings can unmoor your roof, or create spaces where snow and rain can get in and cause permanent damage.
So having the right amount of venting for your attic can extend the life of your roof. Sufficient venting can also match your warranty and potentially save you from expensive repairs down the road.
Attic temperature matters
No matter what the climate is where your house sits, your attic collects heat. This heat must be vented to the outside so that the joists and joints do not expand and contract in ways that are too extreme over the course of days and seasons.
The obvious way to do this is by making sure you have your vents appropriately spaced throughout the attic. The vents should be distributed and not collected in one spot.
This is important because distributed vents allow for some air flow to make sure your attic stays dry and within an acceptable temperature range.
Square footage matters
The general rule of thumb for venting an attic is one vent for every 150 feet, if the attic does not have a water vapor barrier.
If the attic has the proper up-to-code vapor barrier, one vent for every 300 feet of attic space is sufficient.
However, this is not just a square footage math problem. Vents must be distributed evenly across the attic space, with an eye toward the purposeful movement of air in the attic or crawl space.
It is this motion of air, and the introduction of outside air into the attic, that helps to stabilize temperatures and keep your roof free from the movement and loosening that comes from big temperature swings.
Contact a roofing professional near you to get a full roof inspection to make sure your protect your biggest investment.