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The nice roofer wants to use a ventilated drip edge as an alternative to having me extend the rafter tails and replace the facia board. In his defense sofett vent space is a 3/4″ gap behind the facia board that is obstructed with spacer blocks every 16″ or so.
I am familiar with the vent/non vent debate on this forum and for this particular job it will be vent. This will be complete tear off, 30 lb. felt and 30yr shingles, the facia is shot,(shitty gutters and no maintenance) and will have to be replaced either way we go.
I would love to save mom and dad some money, (and me some time) but I have never heard or seen this “ventilated drip edge”. If this stuff is any good do the gutters need any special attention to keep water out of the vents?
Any insight or experience would be most appreciated,
Bill
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Bill. Ventilated drip-edge vents--drip edge vents-or as they are sometimes called "starter vents" are a good idea that turns out to be a bad one in practice.
One of the giants in residential construction regularly used drip-edge vents. But field reports from Toledo, Ohio, Buffalo, New York, Minnesota and other cities in the snow belt, told of snow being driven through the vents six and eight feet into the attic. Construction Research Laboratory was hired to find the cause and a solution to the problem.
The laboratory found that snow will always penetrate the vents unless a baffle is installed to prevent this. With one exception, no commercially available drip-edge vent with a baffle is available.
Another problem with many drip-edge vents is the Net Free Ventilating Area (NFVA) is too little: about 4 square inches per lineal foot. So what? The ridge vent must be driven-fed air-by the soffit vents. The NFVA of the ridge and soffit vents should match, although a 100% match is not necessary.
But as the NFVA of the soffit vent is reduced, at some point say 3 or 4 Sq. Ft., the ridge vent will reverse: take in air instead of exhausting. Many of these vents are easily damaged by ladders. A common complaint from builders is that these drip-edge vents do not keep water away from the siding.
Therefore, if you must use a drip-edge vent use ONLY:-} The ComboVent. 800-298-7610. GeneL