[john t elliffe]

what is the right way to install a 6x6 support for a 14' x 20' deck. The water level is only 2'
below grade. Do I dig a hole below the water line. Do I put the wood on a concrete slab. The
deck is only a couple a feet off the ground. Should I dig it down below the frost line.

[Kstar4u]

what is the right way to install a 6x6 support for a 14' x 20' deck. The water level is only 2'
below grade. do I dig a hole below the water line. Do I put the wood on a concrete slab. The
deck is only a couple a feet off the ground. Should I dig it down below the frost line.

I would recommend a footing at least 2' deep and 18" square (with squared corners). Also... if it were me... I would build the footing high enough so that the water won't contact the wood. Install the 6X6 at least 1" above the top surface of the concrete footing.

[ballengerb1]

If the deck is not attached to another building you don't need to worry about the frost line. The deck will pretty much float with the frost.