Need to get additional venting at a ridge. Metal roof and ridge, currentlly using a “brillo-pad” type material. Thought this would give me the venting I needed.
Any other options available?
Roof is stick-framed gable with a dormer. No room for a gable end vent.
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Replies
If you have a ridge vent, the gable vent will short circuit it and it won't function correctly. Are you sure you have enough air entering at your eaves? That's usually where the restriction is.
Rebuilding my home in Cypress, CA
Also a CRX fanatic!
gable vent short circuit ridge vent? Air is air. Sure hot air rises and in theory leave at the ridge. But a gable vent which allows air to move in either direct moves hot air as well. More holes anywhere the better.
Unable to use a gable vent. There is simply no room above the ceiling joists and the roof joists to get any significant airflow.From my perspective, the ridge is my only option on the "up-hill" side to vent air.Guess I am envisioning some type of "raised" ridge, allowing increased air flow.
Yes, you have enough "exit", but do you have enough "entrance"? Where is the air coming from that is going to be exiting up and out your ridge vent? How many and of what size?Rebuilding my home in Cypress, CA
Also a CRX fanatic!
Installing gabel vents in addition to a manufactured ridge vent will typically void the ridge vent warranty.
What ridge vent warranty? What are the warrantying against??????
They would at least warrant to perform as advertised if installed as directed. Might be a implied warranty of merchantibilty or something to that effect. I am aware that Cora-a-vent specifically tells you NOT to install gabel vents. Why would you want to risk inadequate venting in an attic by not following the manufactures instructions.
Why would Cor-a-vent recommend against gable end vents? As long as you have the soffit vents, I can't see the gable vents hurting.
82544.16 in reply to 82544.15
Why would Cor-a-vent recommend against gable end vents? As long as you have the soffit vents, I can't see the gable vents hurting.
I don't know. That would be a good question to ask them.
Instructions are important to follow ( ok , most of the time. There are times when they should be diregarded or modified , but it's risky buisness).
I once had a proffessor who made the point that even one paragraph of instructions are very important. I was doing something with some yellow glue and made a more or less flippant remark that the instructions are for weinies. He told me that he was involved for an entire summer on writing those instructions on the bottle. He said there were many ways to get less than optimal performance out of the glue, but if I just read the instructions I would be much better off. Humbling to say the least.
Now the above is not to make us all instruction following robots, but you better know your stuff if you don't follow them.
My understanding is that the gable end vents "short circuit" the the convective air flow from the eave line to the ridge. While you would still get ventilation up high you don't get keep air moving across the entire undersides of the roof which can lead to localized condensation on the underside of the roof sheathing, as well as summer "hot spots" due to lack of air flow over the entire attic area.
Yes all the attic air will eventually mix , but it is more efficient to keep the "chimney effect " in place . Imagine the effect of punching a hole in a chimney up high near the termination.
"Ice Damming" is in my understanding a condition caused by having the cold roof warmed from underneath , the melt off running down the roof and re-freezing at the cold eave line. Continuous eave to ridge ventilation keeps the underside of the roof cold over it's entire surface, helping to prevent the "ice damming" Add a gable vent and you allow for the lower sections of the roof to become warm and contribute to the "ice damming"
Cora-Vent is not the only ridge vent company that recommends against gable vents in conjunction with the ridge vent.
Edited 12/16/2006 12:03 pm ET by dovetail97128
Your description of what's going on with Corravent and the other stuff sounds right on the mark.
Beer was created so carpenters wouldn't rule the world.
>>>>>gable vent short circuit ridge vent? Air is air. Sure hot air rises and in theory leave at the ridge. But a gable vent which allows air to move in either direct moves hot air as well. More holes anywhere the better. No exactly true. The path of least resistance will be followed. Air will enter the gable vents and leave at the ridge, leaving the air below stagnant. More holes are better than none, but carefully placed holes are better than random.http://logancustomcopper.com
http://grantlogan.net/
http://www.chicagotribune.com/classified/realestate/homeimprovement/chi-010316outdoorrenovation,0,2786095.htmlstory?coll=chi-classifiedhomeimprove-utl
I can see that to a degree.
I can see that the air can enter at the gable and out the nearest ridge vent hole, leaving most air in the attic unmoved. But then the air near the gable end is cooler and by osmosis the temperature will equalize. The speed of that equalization woudl be in question. so ???? Secondly, air rising from the eave vents all alone the run of the roof would rise to the ridge and out hte ridge, regardless of whether the air at the gable is moving in and out faster.
But, I ani't a physisit (spelling). I like you would trust the ridge vent mfgr.
Need to get additional venting at a ridge.
Why?
Where?
Joe H
I've used the pot scrubber on 4 metal rooves with good results.
What symptoms tell you you need more redge vent?
Is there soffit venting? How much?
You could certainly increase ridge vent ing by framing a very short wall at the ridge, and flashing and capping appropriately. Beware of rain or snow blowing in. Perhaps some sort of metal louver?
>>>>>>4 metal rooves with good results. Sorry, couldn't resist, but it's hoof/hooves and roof/roofs. This is a confusing language we speak.And the ridge vent that you're talking about is my favorite.http://logancustomcopper.com
http://grantlogan.net/
http://www.chicagotribune.com/classified/realestate/homeimprovement/chi-010316outdoorrenovation,0,2786095.htmlstory?coll=chi-classifiedhomeimprove-utl
Thanks. I looked up roof in my Oxford dictionary. Rooves is mentioned as a plural for roof, but is tagged as "disputed". So I guess you are right.
using a "brillo-pad" type material. Under my ridge vent is nothing but metal window screen to keep the bugs out.