asphalt foundation for sheds
Can asphalt be used as foundations for a shed?Answer:
The short answer is no, asphalt is not considered a structural material even though it may feel as strong as concrete or block.
You can still use the asphalt as your shed floor if you are planning a temporary shed or movable shed. Home Depot, Lowes and other home improvement stores have shed that can be built on grass. I'm sure you can do the same and build similar shed on top of your asphalt. My own preference I would much rather have a shad on top of asphalt than on grass, but that's just me.
If you are planning a more permanent shed, you can still use your asphalt as floor but breakout portions of the asphalt at 4 locations, may be 6 or 8(depending on the size of the shed), dig down footings say 14 inches square or diameter and down 18 inches deep.
You can use a piece of sonotube either drop down to the bottom of the holes or just top of asphalt and raise the shed above the asphalt. Make sure the top will make level bottom of shed and make sure the footing locations will form right angle(square) corners of shed. Pour concrete footings using ready mix bags that they sell at home improvement stores. From there install anchor bolts and you're ready to go.
From each of the new footing/piers you poured use a -2-2x8 or 2-2x10 as floor beams that span from post to post and then put your bottom plates for your sheds on top of the the floor beams where you will start your shed framing.