Cobra ridge vent problems

**Ed the Roofer** · 06-26-2008, 03:27 PM

That one sucks if you have gutters OR get snow and ice in the winter.

Ed

**Ed the Roofer** · 06-27-2008, 01:49 AM

Quote:

Originally Posted by dharris008

The simplest type would be the round "Plug" vents. All you need to install these is a drill and the proper size hole saw. 4" work better but multiple 2" will also work.

With the Ridge Vent providing 18 square inches of NFVA per lineal foot, you would havwe to match or exceed that quantity from the Intake Vents you use.

A 2 1/4 inch diameter provides only 1.50 square inches per vent plug

A 4 1/2 inch diameter provides only 3.00 square inches per lineal foot.

You would need to install 3 of the 4 1/2 inch diameter plugs every lineal foot of the soffit on both sides of the roof to only equal the amount of the Exhaust NFVA.

What wrong with that picture?

3 x 4 1/2 inches = 13 1/2 inches, plus, that would require them to be one hole right next to each other and you would never get enough in place.

Those specs are from the C-Series Under Eave Cornice Vents, also known as Mini-Louver Vents, from Lomanco.

www.lomanco.com/ProductPAGES/CirkVents.html

dharris008 · 06-27-2008, 08:28 AM

I understand that plug vents or drip vent may not be the ideal type of ventilation but it is better than doing nothing. As he stated in his previous thread, he only has a small amount of eave and wasn't considering adding eaves to the house. A combination of, simple to install, vents is still better than doing nothing. What would you suggest that is very cost efficient and he will be able to do?

**Ed the Roofer** · 06-27-2008, 09:38 AM

Sorry that I did not expand on that last night.

The most practical product to use for continuous Fresh Air Intake Ventilation, is the Smart Vent, by DCI Products Inc.

It is a tapered, shingle over style product which lays on top of the decking, where a 1" slot has been cut out of the decking at the 6" to 7" point from the eave, which then align with the gap in the product, which then allows fresh air to be drawn through the capillary tubes of the coroplast material and then enters into the attic environment.

This provides 9 square inches per foot and when both sides of the house are done with it, then there is an exact balance between intake and exhaust.

An additional plus, is that it will not get clogged from dust and insulation in the attic and will never get painted shut, diminishing its ventilation capacity for intake.

Do a search for Smart Vent on this forum by my User Name. I have been using it for years.

Ed

the roofing god · 06-29-2008, 12:48 AM

check out "the edge" by Airvent

4just1don · 06-29-2008, 09:51 PM

so with the ridge vents and those smart vents or similiar,,,do I close OFF and not use the end gable vents??

Other question,,,how reliable is that flap closing on the cor-a-vent X5 vent?? Do they last as long as a roof?? AND what kind of shingles work these days?? HERE fiberglass shingles dont seal and tend to blow off,,,was told 100 miles south of here they work,here NOT!! Always did the white asphalt in old days,,,was thinking of going with darker color in a asphalt shake kind. Looks good and supposed to LAST longer.(thicker) and heavier

What say you pro roofers??

rh55 · 03-28-2009, 10:29 PM

We've got a bunch of leaves in our attic, primarily in the section over the garage. Roof was installed in 2004 using Cobra Rigid Vent II ridge vent. The leaves are small oak leaves (Texas red oaks). I was skeptical this was how they were getting in until yesterday.

We had a bad hail storm that left a lot of leaves, twigs, and branches (and one dead bird) on my roof. While sweeping the roof, I found a lot of leaves half in to the grate holes (rectangular) in the ridge vents. The wind here is predominantly North-South, and the roof and ridge vent are East-West, so the leaves and dust get blown up the roof until they hit the ridge vent at the peak. I saw this happening as I was sweeping and stirring up dust.

When I googled for Cobra ridge vent leaves in attic, I found three other posts about this happening.

Adjuster is coming next week, and at least one of the roofers (there have been a lot) has said to expect full replacement (the ridge vent was heavily damaged by the golf ball sized hail).

Which leads to a question - what attic ventilation should I think about replacing the Cobra vents with? Ridge vents make intuitive sense to me as far as effectiveness in venting hot air, but I'd like something that will keep leaves out also.

**Ed the Roofer** · 03-29-2009, 01:19 AM

Shingle Vent II by Air Vent Corporation is by FAR the best Ridge Vent product on the market.

Ed