Snow in the attic

[Roy D. Cooke, Sr]

Originally Posted by dfogleman

The pan vents you mention are a poor means of ventilating any roof, they let a minimal amount of air out of the attic and they can become (as you have learned) a source of air intake to the attic.

Some rules for adequate ventilation are;
1) only one intake source, preferrably the eaves with a strip vent or vented soffit, which is located as low as possible (eaves)
2)only one exhaust point, preferably the ridge on conventional roof lines, again continous WITH AND EXTERNAL BAFFLE AND A FILTER ON THE INSIDE
3)if a power vent is installed the other exhaust sources become intakes, if the power vent is set up to operate with humidity it can pull in the weather.
4)overlapping or multiple attempts at curing a ventilation problem can and will create what is called a 'short circuit in the ventilation' which often negates the performance.

Suggestion, if you want to learn about ventilation check our Certainteed's roofing and ventilation training courses. Get the video that shows smoke tests it can be an eye opener.

where does a person find these video's

Cookie

[sspradling]

I gotta say, I really appreciate all the feedback I've gotten on this subject. I had considered most of the information before I posted my original message, and it always encourages me that first and foremost, the NACHI membership always helps each other out on these message boards. The snow storm we had was unusual for this area, and it caused unique situations, such as snow blocked plumbing vents, covered up furnace flues, major ice damming and a few roof collapses. The snow in the attic was an anomoly, because of the very strong winds during the whole snowfall. This was the only house (out of 20) I inspected during the next 2 weeks that had any snow on the inside. Thanks again to everyone that weighed in.
Merry Christmas.
Stu

[George Mendes]

20 inspections in two weeks. I'm moving down to your area!

[sspradling]

Come on down.
Stu

[Wendy Flowers]

The snow in our attic did not come through vents. It ran in a line matching the ridge row/center beam of the roof. It was 6-9 inches deep, one foot wide and about 30 feet long down the center of the attic floor. With the very high north winds and our house facing north/south it appears that the wind raised up the shingles along the very top ridge of the roof and then the snow just fell straight down into that straight line. Anyone ever hear of that happening?

[Marcel R. Cyr]

Poor choice of ridge venting, is what it sounds like.

Read this article.
http://www.askthebuilder.com/335_Hip...ecessity.shtml

[ROBERT V. YOUNG]

I would love to see photos and where the home is located.
In proximity to what. Hills , valley, large building and witch way was the wind blowing in relationship the the structure.
Has there been water infiltration during a rain storm?