Hey Florida people- re ridge vents /hurr
I question how well ridge vents would keep wind blown rain out in high winds- like a hurricane. seems a 1 inch wall of water being blown up the roof slope would get in the ridge vent based on my just looking at them in the store. the regular roof vents to me would give more protection as they have a much higher inner lip.
Anyone had ridge vents leak?
Replies
the one on the house work fine during katrina, the one on the shop did not. got some of that HVAC fiberglass air filter material, stuff in the vent and its OK now.
>>>>>>the one on the house work fine during katrina, the one on the shop did not. got some of that HVAC fiberglass air filter material, stuff in the vent and its OK now.
Is that the vent on the metal roof?
GRANTT LOGANN - THE LEXINGTONVILLE COPPERWRIGHT
http://grantlogan.net/
yes, both are. house is 5/12, shop is 2/12
I bet the 2/12 pitch was partially responsible. Water was moving slower on it.
GRANTT LOGANN - THE LEXINGTONVILLE COPPERWRIGHT
http://grantlogan.net/
Yeah, 2/12 in a hurricane might as well be a flat roof.
If Tyranny and Oppression come to this land, it will be in the guise of fighting a foreign enemy. --James Madison
A lot of that blew off during Isabel in Virginia. The type that is plastic with the long nails was what I saw blown off the most. During the peak of the storm all of the rain was being blown up the roof on a office building I own right next to my house. There was literally no water dripping off the eaves for a while. The ridge vent had 3" roofing nails but I would never use that type again even with screws, it's just too much pivoting going on with the wind and water blowing up the roof.
the pipe inside the regular passive metal slant back vents is 3 inches high- seems thats a higher barrier than the ridge vents.
The ridge vents rise probably 1.5 to 2 inches, and typically the baffle has a profile that will "bounce" the water back better than the typical drawn pipe (with it's rounded connection to the base) in a metal vent.That said, probably in hurricane territory one should look for a vent specifically designed for such duty. No reason why a ridge vent couldn't be designed to work, but it would be overdesign for the rest of the country.
If Tyranny and Oppression come to this land, it will be in the guise of fighting a foreign enemy. --James Madison
my ridge vent is just a piece of metal bend over the hole in the ridge, no baffle, no nothing.
the pipe inside the regular passive metal slant back vents is 3 inches high- seems thats a higher barrier than the ridge vents.
I have around 18 750 cfm vents in my roof, they didn't leak or blow off. The cobra did on my ofice building 30 feet away.
The Cobra vent is a fiber mat (of some type) that you roll out and nail cap shingles over. No external baffold to keep out wind driven rain. http://www.metroroofingsupplies.com/ventilation_gaf_cobra.htm I'm not sure what the attraction to this kind of ridge vent other than maybe cheap and quick to install.
Many brands of Rigid plastic ridge vent - my favorite is Airvent Shingle Vent II - has external baffolds designed to keep wind driven rain out:http://www.airvent.com/professional/products/atticExhaust.shtml Several competitirs have almost identically copied their design. I have no idea of how it holds up in hurricanes though. Unfortinately I was unable to find a web site that shows a good illustration of how the external baffels work but this one is somewhat helpfull: http://skroofing.com/helpful_information.htm
Here is a web site showing various types of roof vents:
http://www.airvent.com/professional/products/atticExhaust.shtml
>>>>>>>>>>>my favorite is Airvent Shingle Vent II - has external baffolds designed to keep wind driven rain out:That's the only ridge vent I've had problems with - wind driven snow was entering.I'm not in hurricane country, but we have severe thunderstorms with tornados. I've been ridge venting for 20+ years and have found Cobra to be the least problematic (We've had some visual redos with other brands since some are harder to install). All brands that I've used seem to function well. My $.02.
GRANTT LOGANN - THE LEXINGTONVILLE COPPERWRIGHT
http://grantlogan.net/
Strange that no agency has ever tested them- seems that would be easy to do, to see if they leak in say a 50 MPH wind with rain.
After all they are a hole in the roof.
Well... your the master roofer - so I gotta yeild to you - so you think the external baffle stuff is BS?
All I know is the baffle didn't work ONCE. We never changed anything and the problem has not reappeared, but we haven't had the same weather conditions in the last 5 years. I also don't like ShingleventII from an appearance standpoint. And, I'm also not in hurricane country. I'm not poopooing ShingleventII or advocating Cobravent. Just saying what works well for me in my region.
GRANTT LOGANN - THE LEXINGTONVILLE COPPERWRIGHT
http://grantlogan.net/
I suspect that the slope of the roof is a major factor in the mesh style vents. Over about 6/12 they probably work as well as baffle vents, but at 4/12 and below it's probably too easy for wind to drive the rain upward through the vent. At lower slopes it's possible for the baffle in a baffle style vent to be overwhelmed, but is would take a lot more wind/rain.Prior to installing ridge vents (Shinglevent II) on our house I know that significant amounts of snow (enough to leave obvious signs on the cellulose) came through the mushroom style vents.
If Tyranny and Oppression come to this land, it will be in the guise of fighting a foreign enemy. --James Madison
>>>>>>>>>>>>>>I suspect that the slope of the roof is a major factor in the mesh style vents. Over about 6/12 they probably work as well as baffle vents, but at 4/12 and below it's probably too easy for wind to drive the rain upward through the vent. At lower slopes it's possible for the baffle in a baffle style vent to be overwhelmed, but is would take a lot more wind/rain.I suspect you're right.
GRANTT LOGANN - THE LEXINGTONVILLE COPPERWRIGHT
http://grantlogan.net/
If you look at them closely the venting is in the top portion of the vent. I put them on my 4/12 roof and haven't gone thru a hurricane with them yet. That being said, the water would have to blow up the roof then go verticle into the vent and then make a right angled turn toward the roof cut-out and then down towards the ceiling. Odds are the roofing nail heads will pull through the flimsy aluminum and blow completely off. ;-)
In a hurricane ridge and can vents will leak.
But that should be the least of your worries.
Will the roof still be there when you get back is the question.
I care, after all it's my company.
I have seen some leak and some not. Didnt personally see any ripped off without other major roof damage. It would not be a big concern for me.