What the floor thickness is in actuality is what is important. In theory our floors were supposed to be 4" but the contractor apparently skimped on the pour and in the area where the lift was to be installed it was only from 2.5 to 3.5 inches. This is NOT uncommon. They figure, "whose gonna check"? And this was in an industrial building.

The Rotary installer came out before the order was placed and drilled test holes in the floor and we measured the thicknesses. When he and I discovered the floor was less than 4" he told me I'd have to have the floor fixed before they would install the lift. Nobody else has such a program, that I know of.

So, yes, the best thing to do is to check your own floor before you buy a lift if you don't have a good installer like I did do it for you. It cost about $500 to have two 2X2 areas saw cut out and re-poured with high strength concrete 6" thick to support the posts. If you have a 4 poster then you'd have to do all 4 corners. I'd never install a lift unless I knew the floor was strong enough to support it first.

Of course the 4 post lift has not only a lower load per post than a 2 post but also the load tends to be pure compression, unlike the 2 post which can actually rip up out of the floor and fall over if the CG of the car is not centered so it is much more critical in a 2 post application that the floor be strong, still, it is important to check.

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Marty D.

2013 C300 4Matic
1984 BMW 733i
2013 Lincoln MKz