4 Post Lift, weird garage foundation help!

[jsimon77]

I'm looking for a little help. I've been working to figure out how to install a 4 post lift in my 3 stall standard garage. I've got most of it figure out, like how to gain some height in the ceiling...

I'm trying to figure out where the posts for the lift will go. As you will see from the pictures below I have a weird "mound" on the foundation towards the front side of the garage. My slab is post tension.

You can see from this picture where the post can go in black, and where I'd like to put it in red. But you will see in the following picture why that won't work when you see the mound.


<a href="https://ibb.co/1f5b9q4"><img src="https://i.ibb.co/FbMnBwd/Screen-Shot-2019-06-27-at-9-25-56-PM.png" alt="Screen-Shot-2019-06-27-at-9-25-56-PM" border="0"></a><br /><a target='_blank'

I know this is crazy but is there anyway so chisel out a part of that mount to make it level so I can get the post in there? I'm guess the post tension foundation makes this risky?


<a href="https://ibb.co/3m9z8Qt"><img src="https://i.ibb.co/d4wg3xn/Screen-Shot-2019-06-27-at-9-40-37-PM.png" alt="Screen-Shot-2019-06-27-at-9-40-37-PM" border="0"></a><br /><a target='_blank'


What kind of foundation expert would I have to have out to help me understand why that mound is there and if I can cut some of it away?

If I can do this, it will help me get a wider 4 post vs. a narrow one...see my other post

Thanks in advance for any information.

 

[Falcon67]

That looks like a curbing to me, intended to direct water out the door. A little concrete saw or 4" grinder with an appropriate blade could notch that out for the lift pad.

 

[Stuart in MN]

Previous discussion started by the OP on the same topic: https://www.garagejournal.com/forum/showthread.php?t=423540

 

[jsimon77]

Thank you. I apologize for making a new thread… I probably should’ve added to the old one.

I just thought now with a diagram of what I was trying to do I might get some other ideas.

Since I don’t know anything about post tension… Typically that curb is on top of the post tension?

 

[rayra]

What makes you think you've got a post-tension slab? That's unusual around L.A., they're usually all slab-on-grade with rebar in them.

And that 'curb' is also weird as hell around here. Your house on a hillside / sloped street?

You should be able to notch out that location very easily with a concrete saw or angle grinder with a suitable blade.

I also question how close you seem to have placed that post to the door opening. Is that normal positioning for a four-post lift or are you trying to cram one in where it really doesn't fit?

eta it looks like your garage slab might be mostly level with only a short slope near the garage door. Which is also unusual. Typically the entire garage slab is sloped towards the door.
You'd better get a laser level and figure out what is going on with your slab overall, before you wind up putting the four-post feet near the door several inches lower than the front pair. What do your install instructions say about a level floor / placement being necessary for smooth operation of your lift?

 

[jsimon77]

Thanks for the info. The entire community is built on soil that I guess required post tension slab. I've had multiple neighbors do construction and run into complications with the foundation. The other side of my garage has the same sloping slab and curb in the garage.

I can pull the plans and I guess see the details.

I've had a lift person out who didn't think there would be an issue with the lift assuming it's placed correctly.

I'm going to have another expert out to take a look.

What kind of engineer do you think would be able to help figure out my curb thing?

What makes you think you've got a post-tension slab? That's unusual around L.A., they're usually all slab-on-grade with rebar in them.

And that 'curb' is also weird as hell around here. Your house on a hillside / sloped street?

You should be able to notch out that location very easily with a concrete saw or angle grinder with a suitable blade.

I also question how close you seem to have placed that post to the door opening. Is that normal positioning for a four-post lift or are you trying to cram one in where it really doesn't fit?


eta it looks like your garage slab might be mostly level with only a short slope near the garage door. Which is also unusual. Typically the entire garage slab is sloped towards the door.
You'd better get a laser level and figure out what is going on with your slab overall, before you wind up putting the four-post feet near the door several inches lower than the front pair. What do your install instructions say about a level floor / placement being necessary for smooth operation of your lift?

 

[mcj115]

Try thinking of it differently..
Rather than cutting/chipping out a piece could you build pour a small concrete base on top of the slab...the do the same on the other side of the door to level put the front...voila go up instead of down. You just need to make sure the pads you add are solid rather than messing with the tensioned slab.

 

[jsimon77]

That’s interesting. But that would also mean I would have a permanent cement pillar in the middle of my garage? I do like thinking out of the box…

 

[pbon]

The only problem with going up is that the runners are mounted to the crossbar, and the crossbar will be above ground with the lift lowered. You will need stringed ramps or special ramps since the ramps will be above ground at the crossbar end. If you have a low car you will then need longer ramps as well for clearance.

Cut into the mound and this is not an issue.

 

[HoosierMark]

How old is your house? Can you contact the builder and find out who did the concrete work and talk with them. Also before I would modify anything, I would have an engineer or other professional sign off on it. Someday if you want to sell the house, that cut in the concrete could come back to be a real issue on resale. Some home inspector or appraiser mentions it and you lose two months proving everything is fine. Personally I would see if there is anyway I could modify the lift to fit it closer to the point you want it to sit. If modified right you could make so that if you want to change it back to original, you could.

 

[ConCretin]

Your slab obviously slopes. I'm not an expert on 4 post lifts but is the slope itself more of a concern? How much slope can a 4 post accommodate?

The risk to your PT is minimal if you decide to chip a flat spot in the mound or even the slab itself a little bit. PT cables are generally located in the center of the slab. If they are too high, they will pull out during the post tensioning process. The cables are steel and aren't easily damaged or cut. Just go slowly and you'll be fine .

 

[dadsEH]

Any good hire place will rent you a floor grinder...quick.easy.smooth finish.