I built a 16' x 16' "pole barn style" shed. The floor is 3/4" pressure treated plywood. I believe it is the best floor because:
1 it stays dry
2 it's smooth and flat
3 won't rot
4 easy to clean
5 easy to work on equipment
6 easy on the knees & back
7 holds heavy machinery (using 2 x 6's for joists)
RK 55HC,ym1700, NH7610S, Ford 8N, 2N, NAA, 660, 850 x2, 541, 950, 941D, 951, 2000, 3000, 4000, 4600, 5000, 740, IH 'C' 'H', CUB, John Deere 'B', allis 'G', case VAC
And here is the reason I had to build that shed in the first place... as there -used- to be room in the barn for the finish mower, .... but I added a mini horse, and the old 8N.
RK 55HC,ym1700, NH7610S, Ford 8N, 2N, NAA, 660, 850 x2, 541, 950, 941D, 951, 2000, 3000, 4000, 4600, 5000, 740, IH 'C' 'H', CUB, John Deere 'B', allis 'G', case VAC
I doubt pt plywood is going to have a problem with oil, other than absorbing a nice permanent stain.
You could always apply a sealing agent on the top side, and just clean up the spills before they solvated the sealing agent... or use something more permanent like urethane.
bill, why don't u take the pto shaft off the mower and put in further underneath, also i beleive some plastic stapled to the plywood and anchored down in the ground would be better cover for the wheels. as per JM3 TRY AND GET IT OFF THE GROUND. and grease it well.
Sheds aren't such a problem but when I started my digging for pouring of a cement footing, I checked one more time and found that I was a foot short and a foot too narrow for my drive through tractor/snow mobile building. Plus I knew I would want/need more to store so it expanded in length and width to 20X20. Easier to build it once than add on to.