How to Ventilate a Roof
LESLIE: Now we’ve got Bill in Delaware who’s looking to install a new roof. How can we help you with that?
BILL: What I’m looking for is some – a little guidance in the type of roofing material and the – as to the ventilation that they talk about. I’ve talked to a couple of people and they – one had talked about a roof vent which is, I think, in the peak of the roof. And the other contractor that I talked to said that you needed a thermostatically-controlled thing in there that would control the heat and the humidity in the – in your attic.
TOM: Yeah, Bill, that’s a great question. You’re talking about the difference between a ridge vent, which goes down the peak of the roof, and an attic fan, which is mounted in the roof and is controlled by a thermostatically-controlled switch, as you said.
TOM: Now, what we would recommend is passive ventilation, so that’s not the attic fan. It’s a continuous ridge vent matched with continuous soffit vents. They’re actually far more effective than the attic fan. But there’s one additional, major benefit and that is the ridge and soffit vents working together are not going to steal air conditioning from your house.
You have central air conditioning?
BILL: Yes, I do.
TOM: Well, if you turn that attic fan on, it will not only depressurize your attic but it can also dig deep into the living space of your house, because there’s all sorts of nooks and crannies where wires and pipes come through walls. And they’re all connected, thermally speaking, to the inside of your house. So what we’ve seen is that when you turn the attic fan on, it can actually depressurize into your house, as well, and steal away some of the air-conditioned air.
So, attic fans are only recommended in the rarest of circumstances. Unfortunately, it’s one of those things that – this contractor probably started putting them in when he first got in business and just never stopped and certainly is another profit center. But I just don’t think it’s a good idea except in very limited circumstances. I think what you want is continuous ridge and soffit ventilation. That will do the best job.
BILL: OK. Alright. What about the type of roofing material? I’ve seen some that look like thatch and some that look – that they give an appearance of being thatch even though they’re the asphalt or whatever type of it.
TOM: Right. Well, they’re all going to be asphalt-shingle roofs but you’re – what you’re talking about is something called a dimensional shingle. And a dimensional shingle can look like a wood shake, it could look like a slate tile, it could look like red-clay roofs. They’re all good – all made of asphalt. And they’re very good today at the way these shingles are produced to give you that effect.
I would take a look at some of the roofing products made by Owens Corning. They do a really good job with this. And they’ve got roofs, especially in the coastal area of Delaware where you live, they’ve got roofs that can stand over 100 mile-an-hour winds.
BILL: OK. I’ll look at that. And I appreciate it and I thank you for your time.
TOM: You’re welcome, Bill. Thanks so much for calling us at 888-MONEY-PIT.