Floating shed foundation help

18 years ago

I am planning on building a shed/greenhouse on the back of my lot. I have checked with the local township and don't have a lot of restrictions other than size.

I plan to have this 12x16 shed float on 2 4x6 skids. I am in the midst of creating a gravel bed to place thick concrete pavers that would support the skid that will hold up the deck for this shed. From what I have read I believe the best plan of action is to fill each point of contact with about a foot of crushed gravel and then add the concrete 8x16x4 pavers to where the skids will hold the deck level. I do not want to have cement footings so this seems to be the alternative. The placement of this shed is in an area of clay soil where it could possibly sink slightly over time if the soil got wet enough. would cinderblocks amongst the gravel be better? Maybe pavers beneath the gravel?

What is the best material and plan of action for my foundation base? Opinions wanted.

Thanks!

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Comment (1)

Weedy
18 years ago
Last year I erected a 7x7 Rubbermaid tool shed. I realize your structure would be larger and heavier, but maybe this will help. You want a rigid floor that will not become wavy. What I did was to first level the soil without disturbing it too much. Then I laid down about 4 inches of crushed stone surrounded by a frame of treated 4x4s to keep the stone confined. The frame was anchored with 2 ft pieces of rebar driven through 1/2" holes in the 4x4s. This area of crushed stone was slightly larger than the footprint of the shed. Stone was then tamped with a hand tamper. Of course everything was leveled. On this bed of crushed stone, I put a frame of treated 4x4s the size of the shed. I then installed joists, about 16" on center, of treated 2x4s, which I anchored to the frame with galvanized metal brackets. I then used 1x6 deck flooring for the floor. After a year and a half, with a lot of weight on the floor, it shows no sign of sagging. Hope this helps.