How can I stop snow from blowing into my soffit vents and up the attic vent chutes?
Lynnhara
| Posted in General Questions on
We live in Maine, next to the ocean, northeast exposer. When we get blowing snow, it comes up under the eaves, through the soffit vents, up the vent chutes and onto the insulation in the attic. How can we stop this problem? Should we cover the vents and/or stuff the chutes with plastic on the NE side?
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Replies
Lynn,
This is a tough problem, especially during a week like the one we have just had -- with lots of very fine, very light, very dry snow. Plenty of people now have snow on top of their attic insulation.
The good thing is that, due to sublimation and evaporation, this snow almost always disappears without causing any harm to your house. In extreme cases, however, an unvented roof may be the only solution.
I would think that something like furnace filter material in the soffit vents would help considerably. You might be able to find filters made to go in heating registers that are already cut the right size.
The phenomena you described is what causes houses to burn to the ground in wildfire country. Embers make the same journey that light blowing snow does. The snow won't do much harm but fiery embers will burn your house down.
In a wildfire thousands of embers will take this journey through the soffit vents and into attics and land inside the attic. Then it's goodbye home.
I wouldn't worry about the snow landing in the attic. It will dry out.
In fire country I believe that unvented roofs are the wise way to go. Nothing green about your home burning to the ground.
There's a new discussion of the fire problem that Peter mentions, and someone on that thread pointed out a product that is supposed to be an ember-proof vent. It advertises that it can also stop snow, so perhaps that's worth considering.
That discussion is here:
https://www.greenbuildingadvisor.com/community/forum/mechanicals/43986/positive-pressurized-attic-space-fire-protection-and-summer-coolin
The product is here: https://www.brandguardvents.com/