What's the freezing depth at which one should install post for decks by CODE in Coquitlam BC?

Answer 1

Best Answer - Chosen by Voters

freezing depth is around 48 inch but depends cause if your building a fence no need for concrete and when your building a deck that practice of sinking the post with concrete is no longer used and here is why. when you use pressure treated lumber the wood is wet when it is first set with concrete. over time the wood dries out and you will begin to see a space between the post and concrete. now that space is letting water in. and we all know water and wood don't mix. well to say the least the water freezes and thaws causing the concrete to break up and the post eventually comes lose. now if this a fence post that's not much to worry about but if it is a deck and a load point such as a post fails somebody could get hurt. the way around this is

for a fence post most of the trade has switched to sand or peat gravel. i have found if you mix the 2 they work really good

for a deck- you still have to dig your hole below the frost line. and fill with your concrete. the reason why you go below the frost line is to keep the concrete from heaving that's were the ground will push the concrete up and this is caused by the ground freezing and thawing. now before your concrete dries you can by a bracket that sets into the concrete and a 4x4 post will fit into it. or you can set the post on the concrete and fasten it down with a hurricane clip. both ways are excepted in IL, but the best way is to use the bracket because it dose hold the post off the concrete about a 1/4 of an inch. keeps the water from getting to it

Source(s):

carpenter

Answer 2

Check with th local buiding code director in your area. It varies by area.

Answer 3

I'll bet it is at least 48 inches.