Contractor screwed up, what would you do? 2 post lift question

[ericm]

In my opinion you are more then good to go. There are a zillion two post lifts set up on 4 to 6 inch slabs. 12 inches? You are way ahead of most.

It's a 12" deep square footer that looks to be about 2-3' on a side. There's a pic before the pour in post #9.

Maybe it was added later but in that pic there is no rebar and the wire mesh is on the bottom of the slab.

How much force from side to side is there on a post of a two post lift? Is the bar that ties the posts together structural or does it mostly just hold the shutoff bar, cables and hoses?

 

[whateg01]

I’ve got 12 inches under this 3/8 or so deep expansion joint. And the footer and slab are all one cohesive pour

So what you're saying is the control joint is just for decoration

 

[ratflinger]

I've had both, currently a 4-poster. There is nothing that one can do on a 2-poster that can't be done on a 4-poster. Besides, the 4-poster does not need to be anchored. If you are married to the 2-post then a 3/8" cut in a 12" pour is nothing, anchor it an quit worrying over nothing.

 

[whateg01]

I think one could be forgiven for worrying about it. It seems like these threads alternate between "it's just fine so stop worrying about it" and "OMG your whole shop is going to collapse you have to rip up the whole floor and start over".

 

[ConCretin]

There are several areas on concern based on your photos, including but not limited to reinforcing laying on the ground and the abrupt changes in elevation at the thickened areas but with that said, I don't think the control joint issue is insurmountable.

The proximity limitations of anchor bolts to control joints is due to the way anchor bolts react within the slab. The strength of the bolt is dependent on the integrity and depth of concrete above it. A control joint reduces the integrity of a conical area above the bolt,. which is why lift mfg. don't want them near the anchor bolts

The solution may be as simple as installing a deeper anchor bolts but only an engineer can determine this for sure.

 

[mikedodge]

The way you describe it with footings where the hoist would go their cut shouldn't be a problem. It would be more of a potential issue if there was no footing if the slab cracked and heaved right where the hoist post is.

 

[whateg01]

There are several areas on concern based on your photos, including but not limited to reinforcing laying on the ground and the abrupt changes in elevation at the thickened areas but with that said, I don't think the control joint issue is insurmountable.

It's pretty common in flatwork I've seen or been involved in to lay the remesh on the ground and then pick it up as the mud starts pouring in. I don't like it because you really don't know where it ended up, but it's cheap to do so many contractors do it that way.

 

[mm08822]

More info would help................show the 2 pads and distances to all control joints and the bolt pattern plan. More dimensions is better.

You may be able to move the lift a few/several inches away from the control joint while still being well positioned on the footers.

How thick is the floor w/o footers?

 

[ConCretin]

It's pretty common in flatwork I've seen or been involved in to lay the remesh on the ground and then pick it up as the mud starts pouring in. I don't like it because you really don't know where it ended up, but it's cheap to do so many contractors do it that way.

I agree it's common practice among low end residential contractors and I can tell you exactly where it ends up.

 

[mike93lx]

I agree it's common practice among low end residential contractors and I can tell you exactly where it ends up.

You mean it doesn't stay in the middle as they walk back over it??

 

[ConCretin]

You mean it doesn't stay in the middle as they walk back over it??

Even if they make the occasional tug when the owner is watching, the only way it ends up in the middle is if it happens to land on a discarded beer can.

 

[Roothawg]

I just had this exact thing happen to me. I dug 2'x2' square pillars for my 2 post and the garage folks put my door in the wrong place. The concrete seam was right in the way. The lift installer wouldn't put it within 3 inches of the cut. I had to move mine about 3 feet to one side to center it up in the door. The installer basically said the pillars are great but not necessary, based on your fastener type. I never had pillars in my other shop either. It was discouraging, but I never had an issue at the other shop and that lift was there for 20+ years.

 

[beltfeed]

I work on cars with a 4-post - no storage at all. I can do anything that anyone can do on a two post. However it does take a bit longer to set up when elevating the wheels. I was stuck because of time constraints on a job and my thin floor. This is why I just built a second garage with a 12' ceiling and a thick slab. Now I at least have the option of a two-post. Good luck.

James

Not 100% true. I have both a four post and a two post. When I'm putting a car onto the rotisserie for body work it has to be done on a two post lift. When I lift a body off of a chassis or lift the box off of a pickup I use the two post. Yes, you could attempt this with an under sling arrangement on a four post, but it would be a total cluster f***. Both have areas they perform well in and areas they do not.

 

[rust in the eye]

Saw cuts for crack control won't effect the 12" pad for the lift post.
Nothing to worry about here.

 

[decrepitdrew]

More info would help................show the 2 pads and distances to all control joints and the bolt pattern plan. More dimensions is better.

You may be able to move the lift a few/several inches away from the control joint while still being well positioned on the footers.

How thick is the floor w/o footers?

The portion of the floor without footers is 4-6 inches, but has piping for radiant flooring so I can't move it

 

[imma_stocker]

If it's all one slab underneath, I would have the GC or concrete crew fill the joint then THEY provide a pair of steel plates with holes drilled to match lift base and 4 more outer holes. Essentially giving each post a larger contact patch and 8 anchors to reach further from the edge. Hope that makes sense. Filling the void is solely to reduce unseen rust developing under the lift bases. There is zero structural reinforcement with fillers.

After this mistake I would expect a mild above and beyond level of correction. It'll still be cheaper and stronger than breaking up concrete and adding a couple patches. In my experience, slabs never tie together correctly. Last thing I would want under a rig is the lift posts have any movement. And I often shake the hell out of vehicles above my head!