I have the booklet from Rotary right here. No mention of concrete, but I seem to remember details on their website. Which model/lift capacity ? Salesman gave my concrete company the required re-pour. The concrete must also be steel reinforced. I just had a 7" slab section removed and repoured with tied in steel because the slab had cracked a while back right exactly where I want the lift. I'm after a 10,000 unit and 14' etc for my machinery shed. $1500 to cut & replace 6' by 14' with 8 bag mix and tied it steel rod. They want $4750 for my selection and $870 to install. To lift a rear heavy narrrow frame, they recommend an I-beams across the arms. Because of all the "Stay at Home and Unemployed" executive orders, my SPOA10 lift is in Limbo, llllll