Ask Your Question

Angie's List Answers is the trusted spot to ask home improvement and health questions and get answers from service companies, health providers and consumers. For ratings and reviews on companies in your area, search Angie's List.

Top 30 Days Experts
Rank Leader Points*
1 kstreett 240
2 Guest_9020487 110
3 Guest_9190926 105
4 GoldenKid 100
5 ahowell 95
6 KnowledgeBase 95
7 skbloom 80
8 Guest_98024861 70
9 Guest_9311297 70
10 Guest_9400529 70

*Updates every 4 hours

Browse Projects By Category

Question DetailsAsked on 8/18/2017

I live on the water where I get very strong Noreasters with wind and rain mix. Will the GAF Cobra Ridge Vent leak?

Do you have the same question? Follow this Question

1 Answer


Snow Country / Snow Country Advanced are better at preventing that than regular Cobra vent, or most other brands in my opinion.

Here is a prior similar questions with answer also, FYI:

In areas with very heavy blown rain issues or a lot of very cold dry snow (so it stays powdery and does not pack into the vent baffles), I have seen and used heavy (30 mil or heavier) plastic sheeting formed into a seamless trough by rolling the edges around 2x2's and stapled to them, then the 2x2's fastened to the underside of the rafters or truss top chords, located so the end or center are a bit higher than the other, with a 3-4" plastic drain pipe connected to the low point(s) to collect meltwater, leading to outside drip point. (4" not for flow volume, but as preventative measure against freezing solid). As a more professional looking and rugged solution for "designed" blow-in drainage, very wide sheet metal roll flashing (reinforced with wood if it may accumulate snow) works well too - again, sloping to the drain point(s). This is centered under the cutout for the ridge vent but BELOW the rafters so it does not block the airflow from eave to ridge vent - allows collection and drainage of blown-in rain water and collection and holding till melting of snow that blows in. Note the drain pipe should NOT lead into a sewer pipe - can get smell and explosive gas accumulation in the attic because of long periods without any water so it will not maintain trap water - normally just vented a few inches out the wall though in cold winter areas needs to run down inside a warm wall to a warm exit point to avoid freezing up in some areas. (Get tough to design at times, because you cannot reasonably assume that the exit point on a wall will be above freezing (and hence not icicle up) if the attic is melting accumulated snow.

Honestly, I have only done this in EXTREME blow-in cases like in Fairbanks area (where the winter snow if VERY light and dry), along the Bering Sea and Arctic Ocean, on some Antarctic camp buildings, and a few very exposed year-around rain and wind areas like on Nantucket Island and the ocean wind side of Puget Sound islands and peninsulas, and a couple of other unique cases where the building was abnormally exposed to winds on exposed ridges. Normally the amount of blow-in, especially if the attic returns to above-freezing frequently through the winter, is small enough that it may wet the surface of the insulation (quite commonly seen in home inspections as surface frosting and matting of the insulation) but generally evaporates before it causes attic framing damage or more than a thin haze of mildew. This sort of "blow-in diaper" would, in normal areas, be done as a remedy for proven blow-in rather than as initial installation, though I have done it in some cases preventatively in cathedral ceiling/ low headroom attic locations where installing it after the problem appears would be very difficult or expensive.

For your area - unless unusually exposed to major blowing rain storms (say right on an exposed seacoast with those conditions and with roof more or less oriented crosswise to prevailing storm winds), I would (if attic is accessible for inspection after a few storms and putting in catch trough if needed) wait and see and just make a point of checking the attic for wetting after the first few good rainy blows. Of course, if the attic is finished, so any blow-in would be wetting a finished attic room, that would likely weigh in favor of a preventative catch trough.

Answered 3 years ago by LCD

Related Questions

Terms Of Use
Privacy Policy