Ventilation- What’s it all about?

So everyone has been hearing about the benefits  of venting a roof. But a lot of people don’t understand how it works.  But this could be a major difference in prices when comparing roof contractors.  Some roofers are thorough and make sure that there is adequate air flow through the whole system, from bottom to top. But other roofers…no kidding, just slap it up and get paid and leave.

But why do you care if you have adequate ventilation?  Your roof may have never leaked, but there are things that are happening in the attic and with the shingles that you might not be aware of.

Note excessive heat. If it’s 90 degrees outside, the attic temperatures shouldn’t exceed 110, according to home inspector Jamison Brown of AmeriSpec Home Inspection Services in Poquoson. “However, more often than not, around here I find attic temperatures to be in excess of 125 on a 90-degree day,” he says. “This overworks the air-conditioning equipment, runs up the cooling cost and shortens the life of the roof covering, or shingles.”

Venting not only helps condensation and ice back up issues in the winter but also excessive heat build up in the summer.  A hot attic will make your air conditioner run more and bake the shingles from the inside as well the outside.

So how do I know that my contractor is doing it right?

First of all get references  and make sure he has a good reputation. Then ask pointed questions about how he will vent the attic, from the bottom eave, through the attic, and out the ridge vent.  Look for words like intake (where the air enters the attic) and outtake (where it escapes the attic).  Ask about the square footage of exhaust that the products he is using can provide.  Gable end vents always seem to be a favorite with homeowners, but have been proven they provide very little square footage of exhaust.  A contractor should be knowledgeable about these product and where to use them.