Concrete thickness under shef

Many sheds are successfully built without a concrete foundation. I have an old horse barn in my backyard that has been standing since 1959, with a foundation comprised of concrete block in the corners, and a few blocks in the center. I am not sure how you "know" you have to lay concrete, but there are plenty of folks on this site who have sheds of various sizes on types built on a wide range of foundations, including PT wood, concrete block, stone, posts etc.

Perhaps a better way to approach the question of foundation would be for you to explain exactly what you are thinking of building, size, type of floor, type of framing, type of material you want to store inside, your location, and the type of soil, and see what folks on this forum think might be a good, low cost foundation type.

And you may want to check with your building inspector, there could be local rules regulating foundation type and depth. Especially important if you need a permit.

Thanks for responding,
The shed will be in the backyard next to the fence, the size will be 12feet by 15 feet. I am not sure about the soil type On the ground. But the house itself had only been built 2 years ago. Thanks

What state are you located in? Impacts frost depth etc.

I m from Ontario,

Check with your local Building Department. Many require a setback from a fence or side yard to the neighbor before he calls on you.......

Gary