You may want to make sure you have enough concrete to bolt down the lift. I have a 4 post and if i remember correctly you need at least 7". If you don't have enough to bolt it down it will NOT be safe! The two post lift's may need more(bigger/longer bolts) something to look into.
From Mohawk web site: Concrete Floor Requirements: ........ 4000 psi mix 4-1/2”
From BendPak web site: Concrete 4.25 inches thick, 3,000 PSI, cured for a minimum of 28 days.
So check with the manufacturer. It isn't as bad as you may think. But remember many residential driveway/garage floors may only be 3.5" thick.
I went to the trouble to over build my new shop. It has reinforcement steel bar 24" on center (square grid), and the area where the posts go are 6" thick (minimum, dug deeper).
