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frostline depth

 
Barry
Regina
5/30/2011 at 9:23:01 PM
i am building a deck with a roof over head, the deck is 12' by 16'. what i need to know is how deep is the frost line, and how deep do i need to go?
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RESPONSES
6/1/2011 at 9:27:36 PM
Foundation depths due vary across the country and it is best to check your local building codes. In more temperate climates such as central/southern Ontario it is 48". However, the depth is not the only consideration. The bottom of the hole should bell out to help prevent frost lift.
Regards
Kingsway Construction Inc
Glenn Rosborough
Bill
Pierrefonds
7/10/2011 at 9:51:33 AM
i used to work for an architect, and here in Quebec, 4'-6" is the norm unless you go further up north where it is colder and we even went to 5 feet +

The water table level is a definite consideration too, since if it is going to freeze, it likely will heave the column. Today they sell preformed forms that are shaped wider at the bottom than at the top, and these help to prevent movement since the soil is pushing against this conical shape--helpful, but still needs to be deep enough. You local building dept. can advise the best depth for your region.
Bill
Pierrefonds
7/10/2011 at 9:53:14 AM
i used to work for an architect, and here in Quebec, 4'-6" is the norm unless you go further up north where it is colder and we even went to 5 feet +

The water table level is a definite consideration too, since if it is going to freeze, it likely will heave the column. Today they sell preformed forms that are shaped wider at the bottom than at the top, and these help to prevent movement since the soil is pushing against this conical shape--helpful, but still needs to be deep enough. You local building dept. can advise the best depth for your region.
 
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