Hi
Yeah... i figured it was hot topic. I figure 4-5 " thick with #4 bar 18" OC. The Rebar is what gives the floor strenght in tension. The bottom 1/2 is in tension when loaded from the top. But you guys know a boat load more about the real world of garages..... I'd like to get smarter on the subject
Reinforcement is normally put in a slab on grade in the middle of the slab in order to prevent shrinkage cracking. The bottom of a floor is usually only reinforced if its off the ground or if its taking extreme loads like a highway. If you want a slab that will look good for a long time, make sure you have ample reinforcement accurately placed in the middle of the slab.
For a slab on grade, the ground gives a lot of support and strength to the system. For a common lift, footers are not necessary because the steel plates distribute the load just like a the tire contact patch does on the car. The most important detail is to have a continuous slab under the lift, without control or expansion joints. Particularly if you go with a two post lift, the continuous slab will give you the needed strength to keep it stable. The thicker the slab the stronger.
I'd suggest picking out the lift you want first. The ceiling height and floor requirements can be very different depending on the size and type of lift you go with.
