Poor Attic Ventilation Can Cause Roof Shingle Damage
LESLIE: Ted in Missouri is dealing with a roofing problem. What’s happening? Are you getting a new one? Is something wrong with the one you’ve got and you want to fix it?
TED: Yes. Well, yes and no. My wife told me I need to pay attention to the roof and I went on the roof.
TED: Noticed a lot of my granules are missing and some of the shingles are kind of warping upward and I’m kind of curious when is a good time to replace my roof?
TOM: How old is it now, Ted?
TED: It is about – I would say about 11 years old.
TOM: Wow. So it’s only 11 years old and it’s already starting to lose granules and curl?
LESLIE: I mean that’s generally – this is a cement asphalt shingle, correct?
LESLIE: So they should be lasting close to 20 years. Do you …
TOM: Yeah, and the number one reason that shingles don’t last – that asphalt shingles don’t last 20 years – is a problem with ventilation. I suspect, Ted, that you may be overcooking that roof. Now, how old is your house? Is it 11 years old or is it older?
TED: No, it’s 22 years old.
TOM: Wow, so the first roof must have only lasted 11 years.
LESLIE: (overlapping voices) Only lasted 11 years.
TOM: OK, so now we’re getting to the bottom of this.
LESLIE: But now, do you know, Ted, is the new roof – or well, the 11-year-old one that’s on there now – was it put on top of the old roof?
TED: Yes, it was.
TOM: Yeah. Alright, listen Ted. Here’s what we need to do. First of all, there’s definitely a ventilation problem in that roof space and that’s why it’s overheating. So here’s what we’re going to recommend. What design roof is this house? Is it a ranch, colonial? What is it?
TED: It’s just a basic – the person who put it up, he built it on his spare time and …
TOM: OK, but is it a two-story colonial or is it a ranch? What does it look like?
TED: It looks like a colonial.
TOM: OK. So here’s what you need to do.
You’re going to have a long ridge down – across the top. And do you have a single-story section with a garage in it?
TOM: Alright. So here’s what – and does the garage have any living space under it or is it just a garage?
TED: It’s just a garage.
TOM: Alright. So what we need to do is at the [ridge vent on the top of the two-story section] (ph) we need to add a ridge vent and that’s going to go down the entire peak of the roof. I want you to get one made by Air Vent. It’s a CertainTeed company. I think their number is 800-Air-Vent. At least it’s been for many, many years. This vent is going to open up the top ridge space and let air get out of it. The reason I like the Air Vent ones is because they have an extra little flap on the side that speeds up the depressurization.
TOM: So as wind blows over your roof it sort of sucks the hot air out of the attic space.
Now, that’s only half of the solution. The other half is the soffit vents at the overhang. You’re probably going to need to pull off whatever soffit material is there because if it’s covered with vinyl or aluminum soffit material it’s not letting any air in unless it’s perforated. You need to have fully vented soffits. This way you’ll have air that goes in the soffit, rides up under the roof sheathing and cools it in the summer, which in your part of the country is going to be critical to making that roof last …
TOM: … and it’s going to exit at the ridge.
Now, the flip side of this is if you cool the attic off in the summer you’re also going to tend to dry out the attic space in the winter and that’s a good thing because it makes your insulation more effective. If you have a house that’s got a roof that’s only lasting you 10 or 12 years, it is definitely not ventilated properly.
LESLIE: And you need …
TED: So when should I start doing this? I mean it’s coming up to winter time so it’s probably not a good idea to do it now.
TOM: No, I would wait til the spring.
TOM: At this point, I would wait til the spring. But it’s definitely going to be one of the first projects you do this spring and if you do this the correct way, Ted, you’re going to be good to go for the next 20-plus years with that roof.
LESLIE: And you want to remove all roofing material from there and start from scratch.
TOM: Yeah, definitely.
TED: OK. Start from scratch.
TOM: Because the additional roofing material holds a lot of …
LESLIE: Cuts its life span.
TOM: Yeah, holds a lot of heat and it actually will accelerate the deterioration of the upper layer.
TED: OK. Alright, well thank you very much.
TOM: You’re welcome, Ted. Thanks so much for calling us at 888-MONEY-PIT.