Cobra ridge vent install done right?

Thanks to Wilma I got a new roof last year. While up in the attic doing some insulating I noticed there has only been a small cut at the ridge. Maybe 1/2 to 3/4 of an inch on only one side. I know they used Cobra vent. Is that enough of a gap? Does it matter or should I have them do it over? Seems allful hot up there while insulating on not a really hot day.

First off do you have soffit vents? Vents that are at the bottom aof the roof? We will start here. The cut is not enough, there should be 3/4 each side. But that is not a major problem cobra 1 is junk to begin with. Does it look like a charcol filter by any chance? If so it only flows a max of 14 inches.

Yes I have continuous soffit vent on both sides of the house. It is that metal vent about 3 inches wide runs down the middle of each soffit.
Yep the vent is that charcol filter looking stuff.

make sure that the insulation is not blocking the airflow from the soffitts to the ridge. take of the ridge, cut the other side and put on GAF snow country vent.

Do as Marshall as explained and check the insulation.

Go to the link below. It tells you how the manufacture wants the ridge vent installed. Give those directions to your roofer. He needs to read them it sounds like if he only cut 1/2" to 3/4" opnly on one side.

We use GAF Snow Country on all of our jobs that require ridgevent. Great product for snowy states.

Here is that website -

Here is a link for the GAF Snow Country:


Are you in the Fort Lauderdale area? If so, I graduated from Stranahan back in '85 & someone I went to school with is a roofing contractor - they can come out & take a look no charge to see exactly what your problem is. PS to Timothy: zero chance of snow… LoL

If your only issue is a rige cut that is too small & foam type ridge vent, then this can be overcome fairly easy (depending on your level of ability, of course).

One question before we go too much further is in regards to what your contract states. If you only have “add ridge vent” then in the basic sense of the contract you’ve been fulfiilled in product (but not exactly in process if the gap is too short & only cut on one side).

Knowing construction in South Florida, the pitch of your roof is probably around a 6:12 which is an easy walk, but makes the eaves harder to get all the way into for a perper check of how your insulation is stuffed (but you should be able to see if there are any baffles in place).

If you decide to do the ridge vent yourself, get some 3 Tab shingles (typically 33 linear ft. per bundle) in the matching color & either the Cobra II or Cobra III (the 3 version has nails snapped into the plastic, the 2 version needs a separate purchase).

Snap a chalk line 1" down from each side of the ridge center (tap in a nail on one end if doing a solo job) & then set a circ saw just deep enough to cut the decking but not too deep that you penetrate the rafters. Rip out the decking, then nail in the ridge vent & add shingles over this.

NOTE I like to stop cutting the roof deck by around 6" or so on the ends of the ridge vent to privent any intrusion of water from these ends.

Good luck…


PS to Timothy: zero chance of snow… LoL

I was running with what Marshall said.

I do not see anywhere where it says where Frank is from… other than the Frankfla - i was thinking maybe flroida but wasn’t sure - just ran with previous posts…

LoL back at ya !! :stuck_out_tongue:

its called snow country, but doesnt mean you can only use it in a snow climate. it is the same thing as cobra II & cobra III.

I went with his comments about Hurricane Wilma & his ID that has “Fla” in it… Wilma went across the Southern end of Florida then took a L turn & grazed the Carolina coastline.

Elementary, my dear Watson…

Should have mentioned Boca Raton Fl about 15 minutes north of Lauderdale.

I know the insulation is good, did it myself and double checked today. No blockage there. I have a five year labor and material warrenty from the roofer. Went with an established local contractor, paid more but figured if there were problems I could find him. I was leary of all the contractors that got sucked in by Wilma. Figured being they all had Texas tags they might be hard to find if there is a problem. Did have a leak, called the roofer and had a guy here within an hour. Turned out to be not the roof but some old stucco on a dormer wall.

I looked at the product links. That is not how they did it. So I figure if the roofer didn’t follow the manufactures instructions they should do it right, that is what I paid for.

Seems like cobra isn’t too popular with you pros. Being the contract says “ridge vent” if I want something better that would be on my dime. Looking at the links and doing the calculations with the cobra I would be just right on the min NFVA. The Cobra two I am above. Is it worth it to use another product.

Thanks for all the quick and helpful replies and links!

Frank, if you ever get down to Deerfield Beach you should eat @ Rattlesnake Jake’s - it’s directly across A1A from The Whale’s Rib (a Flanigan’s restaurant & bar)… the area where A1A bumps E / W @ the DFB pier.


Funny you mentioned Texas plates as I’ve been in Texas 12 years now & done some hurricane work in Florida - Fort Pierce & Port Saint Lucie - two years ago. We contracted with two handyman types who go out on any service calls if needed (not that there have been much; just a few odds 'n ends).

Anyhow, I like the GAF Cobra III for the snapped in nails they provide with it, however the Cobra II seems to have a bit better in the way of baffling. The mesh vent looks somewhat like a long mesh similar to a re-cleanable a/c filter. Personally, I don’t like this design as it doesn’t allow for as much unrestricted air flow in comparison to the GAF CII & CIII’s.

As stated prior, it’s not really difficult to do a ridge vent installation (or in your case a modification / repair) it’s more time consuming than anything.

ditto gtp1003,
cobra is junk.
sideways florida rain gets to the cap nails.
get yourself a good aluminum ridge vent.
or a couple of turbines on the back.
they also make at soler power vent, and the reason i
tell you that is because it would be easier to add one of those than
to replace the cobra, therefore not tearin up your new roof.


It’s not that hard to remove and replace cobra with a different ridge vent and if done correctly, will not “tear up” your new roof. We do it all the time.

Snow country, shingle vent 2 cobra 3 these are all good ridge vent. Removing the vent is not that big of a deal just time consuming. Just make sure you have a 3/4 to 1 inch slot on either side of the vent. Also i was thinkning how much do you have on the roof? There might not be enought to properly ventilate the roof. If you could please send us the length and width of the home with an idea how long the ridge is. This way we can see if you have enough soffit vents and enought ridge vent. Thanks in advance i know im asking alot but trying to make sure that we have enough to make it worth the time to do it correctly. Kevin

Gweedo, I know on other threads I have stated how I don’t get involved in the “what’s better looking?” discussion, however I have one exception:



& Those metal ridge vents are nearly as bad looking…

I’ll stick to the Cobra III… but again, if the roof is too low a profile, I won’t put on any kind of static ridge vent due to sideways winds (trust me, we get 'em here in Texas just as much as Florida & I will suppose any coastal area is just as prone).

From a functional comparison, according to the GAF brochures, 48 linear feet of Cobra III or Cobra III ridge vent is equal to 10 active turbines. Imagine a day in mid July where there’s next to no wind; the turbines aren’t moving but heat is being generated.

If this no wind area has a correctly ridge & eave vented house, then the heat rising properties will take over & active airflow will occur. Not so with turbines.

This image has to do with Thermodynamics & really isn’t appropriate for what we’re (or at lead ---->I’m<----) talking about, but I thought it would be a nice graphic to paste here. :stuck_out_tongue:

An interseting note on the Cobra III, in its former life it was known as Headrick Full Flow, that is until GAF bought Headrick Building Products and renamed the vent. Besides selling the Full Flow with maized nails, Headrick was very good about running independent airflow testing that gave actual airflow results compared to a vent’s claimed Net Free Vent Area, which is the vent industry’s standard. One thing you won’t find anymore on the Internet is Headrick’s ariflow numbers, which weren’t kind to any of the Cobra products that had the woven mesh material (the original Cobra roll and the Snow Country, which has it installed in the center for a filter). In reality, the Cobra III has better actual airflow than the Snow Country products.

hey Steve - I knew about that. good info though for those who don’t. I have the actual numbers somewhere around my office. If i find them, I will post.

Hey GTP1003
Area I am most concerned with is 18ft length of ridge by 35ft . I ran the numbers based on the specs on on the cobra II product and I get I need at least 8.5 feet if I did it correct. Seems if I do it right I should get a bunch more air moving than I have now.

Not too keen on the wind turbines. Every storm we have I have gotten a few of them in my yard while the neighbors with the ridge vents haven’t had a problem.

Not worried about dificulty, seems straight forward. Still working the issue the roofer did it wrong and they need to be fixings it. This time I will get up there and watch.

Frank - you ask and we all shall try to give you our input.