What about ridge vents?

[Sandman]

So we've talked about attic fans, how about ridge vents? I'm looking into putting a new roof on my house and I've been reading about ridge vents. Any thoughts experiences?

[Silver_2000]

if i were building a house I would seriously consider them ...

[dboat]

I have had them on a house before and I think the really work. Having said that, there are some that are not all that enamored with them. The issue is that hot air doesnt flow downward, which it has to do to go through the ridge vent.
I think they work.. you have an opening at the peak of your roof and the hot air will work its way out.. I dont have them on my current house, and if I did, I probably wouldnt have had the power vents installed.

Dana

[Moonshine]

Can't comment on the ridge vents, but if you're doing a new roof I strongly recommend doing a Category 4 roof. Your insurance company will likely give a discount if you put one on, and for me, it's been a really good investment. I haven't had any hail damage, but I frequently get high winds, and my original roof suffered so much wind damage that insurance finally totalled it. I put on a Cat 4 roof warranted for 50 years, guaranteed to take sustained 90 MPH winds and/or 3/4" hailstones with no damage. It's been worth every penny I put into it.

[SILVER2000SVT]

Ridge vents work well as long as you have enough of them. If you have a gabled roof and use them the entire length of the peak ridge you have enough. I see some people putting them on the peak of a hip roofs where the top ridge only represents 20%-30% of the length of the building. You would need to supplement them with additional means, like a turbine. I'm pretty sure they don't recommend using ridge vents on the corner ridges of a hip roof.

I don't understand Dana's comment about the "downward flow"? You still must use soffet vents to allow fresh air into the attic which creates a chimminy affect when used with ridge vents. My understanding is that it's much more effective than a single point of exhaust ventilation like a turbine or power vent.

I put them on a barn I built a few years ago and that barn was much more comfortable than another shed I had with simple vents at the gables. There are some tricks to installing them properly that my roofer neighbor taught me. You need to screw the ridge vent in place with exterior deck screws something like every 6-8" and use 3" roofing nails to attach the cap shingles on top of the vent. It seemed like overkill to me, but he said it was absolutely necessary, and that he knew from experience.

[PUMP]

Ridge vents are the first choice for attic ventilation. Some limitations are indicated for example, ridge vents won't work on a gabled roof where the gable ends have openings to attic as the air flow is short circuited.

For the ridge vents to work well, you need at least 1-sq-ft of soffit vent opening for each 150-sq-ft. of attic area.

[dboat]

Ridge vents work well as long as you have enough of them. If you have a gabled roof and use them the entire length of the peak ridge you have enough. I see some people putting them on the peak of a hip roofs where the top ridge only represents 20%-30% of the length of the building. You would need to supplement them with additional means, like a turbine. I'm pretty sure they don't recommend using ridge vents on the corner ridges of a hip roof.

I don't understand Dana's comment about the "downward flow"? You still must use soffet vents to allow fresh air into the attic which creates a chimminy affect when used with ridge vents. My understanding is that it's much more effective than a single point of exhaust ventilation like a turbine or power vent.

I put them on a barn I built a few years ago and that barn was much more comfortable than another shed I had with simple vents at the gables. There are some tricks to installing them properly that my roofer neighbor taught me. You need to screw the ridge vent in place with exterior deck screws something like every 6-8" and use 3" roofing nails to attach the cap shingles on top of the vent. It seemed like overkill to me, but he said it was absolutely necessary, and that he knew from experience.

The comments I read related to the design of the ridge vent. The hot air has to flow up and then down to exit the vent. Since hot air rises, there has to be some pressure or other force to get the air to go down to exit the vent. This path is created because the vents design is like an upside down V.

Dana

[Silver_2000]

The comments I read related to the design of the ridge vent. The hot air has to flow up and then down to exit the vent. Since hot air rises, there has to be some pressure or other force to get the air to go down to exit the vent. This path is created because the vents design is like an upside down V.

Dana

the pressure comes from the hot air behind it ..

As long as the column of hot air is taller than the down portion of the vent you will be fine- to say nothing about the action of wind going sideways thru the vent

[Sandman]

Ok, so it makes sense to vent the attic during the summer to get the heat out. What about the winter? don't you want to keep the heat in? Doesn't seem like you can cap off a ridge vent.

[dboat]

Ok, so it makes sense to vent the attic during the summer to get the heat out. What about the winter? don't you want to keep the heat in? Doesn't seem like you can cap off a ridge vent.

You dont want to do that because there is humidity with the heat and it can end up getting your insulation all wet. Vent the attic all year round.

Dana

[Silver_2000]

never understood the people who climbed on their roofs to put plastic bags on the whirly birds in the winter

[Mark #2]

never understood the people who climbed on their roofs to put plastic bags on the whirly birds in the winter
Okay, I'll admit that I did this at the rent house that I lived in for many years as it was wind tunnel in that house and it did help on the heating bills.
There was almost no insulation in that house and we could see the aluminum wires spark behind the socket covers until I sanded and tightened them, that was when I decided maybe this isn't a good place to live. ;)

[Silver_2000]

Okay, I'll admit that I did this at the rent house that I lived in for many years as it was wind tunnel in that house and it did help on the heating bills.
There was almost no insulation in that house and we could see the aluminum wires spark behind the socket covers until I sanded and tightened them, that was when I decided maybe this isn't a good place to live. ;)
Point taken
my assumptions were that insulation was decent
I would have done the same in a rental - cheap quick way to save money

[PUMP]

Ok, so it makes sense to vent the attic during the summer to get the heat out. What about the winter? don't you want to keep the heat in? Doesn't seem like you can cap off a ridge vent.As air heats up it decreases in density so it rises. The opposit occurs when air cools. Result is very minor air flow in attic when outdoor air is cold

[mikelemoine]

I had to re-roof my rental house here in Orlando about 5 years back. When I was working with the roofer (a friend), I mentioned that some of my planks had split and a few had broken and were hanging down, even though there was no rot and it wasn't leaking. He said it was because I had no ridge vents (or any vents for that matter) and the attic was getting so hot it was cracking the wood. He replaced a few boards and added full length ridge vents. So far so good, but I'll have to get back to you in about 10-15 years to give you the final review!

To make a short story long, my trusted roofer said ridge vents are a must in hot climates. They keep the shingles and boards a little cooler so they last longer.

[dboat]

Ridge vents work, IF, you have enough ridge on the top of the house to make sure there is enough sq footage of vent, as stated before, if you have a bunch of hips on your roof, you might not get there.

I had two powered attic vent fans added to my house. They are set at 110 F to come on.. they havent come on yet.. Honestly, I think part of the reason they havent is because the opening is so big for the fan that compared to the other little vents that were there, just the opening alone is venting a lot more hot air and the air can easily move out without having to go up then down and out.. of course this is my personal opinion and not backed by scientific fact.
The point is, make sure your attic has ample venting and air movement, passive or active.

Dana

[Sandman]

I was driving around today looking at some of the work of the potential companies that will be replacing my roof. Outside of 2 houses on my street that had roofs put on in the past 60 days, I didn't see a single house with ridge vents. Any clue why? Are they that new? Or just now taking off? Any real cons that you can think of with ridge vents?

[dboat]

I would guess that they might cost a bit more. Most people dont think this through and the roofer doesnt want to spend the extra money.. no reason to not do them, none.. get them.. keep cool upstairs.

Dana

[dboat]

Ok, well, if my new powered attic vents didnt come on today then either they are not working or my attic is incredibly well vented now.. and they did come on and the attic is not nearly as sweltering as it has been. The fans even cycled off at one point.. the attic is still hot, since they are set at 110 degrees, but not so much.
Also, my plan to cool the garage down has really worked too.. the powered attic fans, a trellis on the side of the garage and solar screens over the windows. The garage is reasonable. Its as hot as the air temp.. used to be that the garage was much hotter than the outside.. its nice when a plan comes together.

Dana

[Moonshine]

its nice when a plan comes together.

Dana

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