I live in Fairfax, VT, zip is 05454. I'm building a deck, and I'm going to be pouring concrete into sonotubes. Everything I've read states that the bottom of the sonotube must be below the frost line. Nowhere does it state how deep that might be. I assume that the USDA or the department of the Interior must have a map on this kinda thing, but for the life of me, I can't find it. Any ideas?
Frost line depth map?
May 07, 2005
5 Replies
Hi, You local building inspector ought to know or building contrators. It's 6 feet where I live.(Alberta). I don't think your wether is colder than ours in winter. Tony
The USDA Zone map might be a good guideline. I am in Zone 6 next door to you. Bottom of footing 18" below finished grade here.
Your local building inspection office can tell you for sure what it is in your area.
BTW, around here at grade decks just float. Not sure what the rules are for those over 8' off the ground.
Colbyt
The building inspector will know. Here it is 48" May bell be that in your area a bit north of me.
Edwin where are you? Someplace cold I see.
Colbyt
You need a local source, building inspectors, contractors, etc. Depth of frost can vary tremendously over a short distance. And those that use the published depths may end up with major repairs during an extreme year. For your purpose it is probably not that critical.
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