Ridge vents--Rigid 4ft sections vs Roll-on type
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The Shingle Vent II Ridge Vent, manufactured by Air Vent Corporation is usually the one that is held in the highest regard from most astute roofing contractors.
The Cobra Snow Country is a near identical knock-off product.
The roll vents typically will have an uneven nailing pressure, resulting in an excessively periodic fastening pattern, giving the roll products a wavy and uneven appearance.
Additionally, the more premium ridge vents mentioned also contain an exterior wind deflecting baffle, which creates additional possitive pressure on one side of the vent and negative pressure on the opposing side of the vent, resulting in increased exhaust air flowage from winds as minimal as 3 miles per hour and increasing in it's performance the higher and stronger the exterior winds blow.
Ed
The Cobra Snow Country is a near identical knock-off product.
The roll vents typically will have an uneven nailing pressure, resulting in an excessively periodic fastening pattern, giving the roll products a wavy and uneven appearance.
Additionally, the more premium ridge vents mentioned also contain an exterior wind deflecting baffle, which creates additional possitive pressure on one side of the vent and negative pressure on the opposing side of the vent, resulting in increased exhaust air flowage from winds as minimal as 3 miles per hour and increasing in it's performance the higher and stronger the exterior winds blow.
Ed
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I've been reading Ed's posts for some time, both here and on two other forums. He knows his roofs, a true professional.
Here is the science behind his statements: http://www.oikos.com/esb/30/atticvent.html
And the test results, again proving his point: http://files.buildsite.com/dbderived-f/airvent/derived_files/derived20936.pdf
I'm not sure if it was mentioned, as rain/wind goes over the ridge- water is forced into the attic through the ridge vent (non-baffled), which could quickly render your insulation useless and cause mold growth. Along with adding additional weight on the wallboard ceiling, causing nail dimples and ceiling material sag. Be safe, G
Here is the science behind his statements: http://www.oikos.com/esb/30/atticvent.html
And the test results, again proving his point: http://files.buildsite.com/dbderived-f/airvent/derived_files/derived20936.pdf
I'm not sure if it was mentioned, as rain/wind goes over the ridge- water is forced into the attic through the ridge vent (non-baffled), which could quickly render your insulation useless and cause mold growth. Along with adding additional weight on the wallboard ceiling, causing nail dimples and ceiling material sag. Be safe, G
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Thank you Gbar. Those were very kind words and appreciated sincerely.
Ed
Ed
I'm a little confused by the illustrating figures in those links. They make it look like the baffle would allow rain water to pond up in the ridge vent and spill into the attic?
:confused1:
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96 Posts
I tried some of rolled ridgevent a few years ago & indeed had some problems with it. On a shallow slope 4/12 or 5/12 the wind would blow water up that slope & enter the building.
I went back to the Shinglevent II. Have never had a problem with it. We install at least 3000-4000 ft of it every year.
Dale Chomechko
DC Roofing Inc
I went back to the Shinglevent II. Have never had a problem with it. We install at least 3000-4000 ft of it every year.
Dale Chomechko
DC Roofing Inc
Installing GAF Snow Country II Ridgid vent
Will be nailing it tomorrow (later today). Was looking at it and fretting abit about the seal against wind driven rain and wondering about the louvers in the ends especially and how well they will keep it out. I dont have alot of experience and spent much of the day trying to figure out the nailing platform details for my situation and how far to actually run the vent on my hip roof as the hole had already been cut and was within 2 inches of the hip joints. Manufacturer recommended 6 inches from the ridge ends minimum to prevent wind-driven rain so I will be shingling over 4 inches of hole with ridge caps. I will be butting the ridge caps up to the end of the rigid vent and then nailing them over the top. Hope Im doing the right thing. The top run of shingles on either side I installed at standard 5" exposure I think the ridge vent may need to be nailed with the edges past the start of the rain gutters (both sides shingles will need to be trimmed), Im not sure thats cool. I will blackjack all nailheads under the rigid vent and any gaps or butt joints up to the precut hole.
Will be nailing it tomorrow (later today). Was looking at it and fretting abit about the seal against wind driven rain and wondering about the louvers in the ends especially and how well they will keep it out. I dont have alot of experience and spent much of the day trying to figure out the nailing platform details for my situation and how far to actually run the vent on my hip roof as the hole had already been cut and was within 2 inches of the hip joints. Manufacturer recommended 6 inches from the ridge ends minimum to prevent wind-driven rain so I will be shingling over 4 inches of hole with ridge caps. I will be butting the ridge caps up to the end of the rigid vent and then nailing them over the top. Hope Im doing the right thing. The top run of shingles on either side I installed at standard 5" exposure I think the ridge vent may need to be nailed with the edges past the start of the rain gutters (both sides shingles will need to be trimmed), Im not sure thats cool. I will blackjack all nailheads under the rigid vent and any gaps or butt joints up to the precut hole.
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You could cover up that slot with Ice and Water Shield first, before shingling it.
Ed
Ed
Thanks I have extra ice and water
Just got back from getting ring-shank and spiral shank 3" nails and a washer assortment small enough to "make" a roofing nail out of either of them since they have smaller heads. Will test to see which one pulls out harder on scrap wood. I can still probably install some wood to fill the "over"-slot ends. Then put ice and water over the patch. It will be a little more than 4" as I re-read the GAF instruction and it said rigid vent should overshoot the slot 6" minimum and the ridgid vent itself should be 6" minimum from the hip joint. So apparently the slot should be 12" minimum short of the joint. Well I better get busy ... thanks for the input. Keith
Just got back from getting ring-shank and spiral shank 3" nails and a washer assortment small enough to "make" a roofing nail out of either of them since they have smaller heads. Will test to see which one pulls out harder on scrap wood. I can still probably install some wood to fill the "over"-slot ends. Then put ice and water over the patch. It will be a little more than 4" as I re-read the GAF instruction and it said rigid vent should overshoot the slot 6" minimum and the ridgid vent itself should be 6" minimum from the hip joint. So apparently the slot should be 12" minimum short of the joint. Well I better get busy ... thanks for the input. Keith
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The ridge vent I have has little slots in the baffle - allowing water to drain
Put the wood to it 
Fit nice too and didnt have to tear the felt, got a truss just right on either side of my slot patch so that went pretty slick. Just tap tap tapped it in from the side. I did install the rigid vent backwards tho Noticed it after installing all but the last piece with ring shank nails. You start with an overhang pointed out (which seemed to me like it didnt make sense) so that if you have to trim the last piece you will have an overhang to connect with as well as a wall at the opposing end. Woops. I trimmed both ends tho and they mate ok ... not with an overhang but the sides are flush and blackjack and shingles will seal the joint ok I think. Im not ripping out all those ring shank nails to redo it. I have 8 inches on 1 side and 7 on the other to the hip joint. I just have to cap those areas and the ridge vent tomorrow and DONE. Except for cleanup ((
Fit nice too and didnt have to tear the felt, got a truss just right on either side of my slot patch so that went pretty slick. Just tap tap tapped it in from the side. I did install the rigid vent backwards tho
Noticed it after installing all but the last piece with ring shank nails. You start with an overhang pointed out (which seemed to me like it didnt make sense) so that if you have to trim the last piece you will have an overhang to connect with as well as a wall at the opposing end. Woops. I trimmed both ends tho and they mate ok ... not with an overhang but the sides are flush and blackjack and shingles will seal the joint ok I think. Im not ripping out all those ring shank nails to redo it. I have 8 inches on 1 side and 7 on the other to the hip joint. I just have to cap those areas and the ridge vent tomorrow and DONE. Except for cleanup ((
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We use the Shingle Vent II, almost exclusively, as our ridge vent. Primarily we do this because I feel it to be better with the external baffels. On most jobs I don't find there to be any signifigant cost difference either, so I will err on the side of what's better vs what's cheaper.
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