Hey everyone, asking the lift installation experts here. I am going to be installing a 2 posts base plate low ceiling lift in my garage and I am very unsure of the installation. I have a center drain in the garage so I have a slope in the floor.

Here is a drawing of what I mean and a picture of the type of lift I want





If I rest the post directly on the ground and put them level, I am going to have arms that are not the same height and the arm of the lowest post with the angle of the floor will probably hit the base plate.



Now the first thing that comes to mind is to shim the lower post so that it comes to the same height as the other one. The problem is that the base plate which is resting on the floor is going to be too low and probably hitting the mechanism under it so I would have to shim the base plate also which is truly not something easy. It comes even worst in the fact that the car is going to be 1 inch lower on the side of the post that was raised in relation to the arms since the car is resting on the sloped floor. We all know that 1 inch on a sports car like a Porsche makes night and day difference in being able to put the arms under the car.

Here is a picture of what I am talking about.



Now what i was suggested by Jeff at Bendpack is to live with the slope and just make sure the posts are parallel and that the arms when fully extended are in line one to each other. What this means is that the posts would be parallel but not plumb (level vertically, don't know if it's the right word).



Of course the drawing is way to dramatic and obviously the angle wouldn't be so big, if I have an inch of slope from side to side, that would mean that my post would be about ¾ of from vertical level from top to bottom. This translate to about 0,5 deg off from level.

He said that the stress on the bolts would not be enough to create any problem with that kind of installation. What I see though is that the car is going to be lifted parallel to the floor so at a 0,5 deg side to side, which is not level.


This would make things 10x easier but is it safe enough? Than again, is putting a 1 inch thick steel plate under a post as a shim safe?

What do you guys think about it and what should I do? I really want to avoid pouring a new slab as this one doesn't even have a year and when I designed the garage, there was no lift in mind but now plans have changed and I am trying to adapt the best I can.

Thanks for you help.

 

As long as your slab is thick enough now for a lift, I'd plug the drain, etch the concrete and pour a self leveling layer to square it up.

 

My only experience is with my four-post lift so what I suggest may not hold true. But... I had a similar situation so I plumbed up all four columns and then adjusted them so they are lifting level. If the two-post lift doesn't have any up/down adjustments then this isn't an option.