Car Hoist Accident, Need Help!!

[FordGuy1622]

So i have a significant issue. I recently fulfilled my life goal of buying a hoist and installing it in my garage. I had some company come out and pour a 4 inch slab for my garage like 10 years ago, and finally last month bought a hoist and installed it. Lifted a small car no issues, lifted a hummer no problem, well last night i lifted my F250 Diesel and needless to say the floor gave out and completely cracked. The hoist post on one side is leaning in and is not sturdy enough to lift my lawn mower (exaggeration) let alone a car but i really want to get this done so i can start working on my cars on the hoist instead of on the cold floor. The truck only weighs like 3 tons total and the hoist is a 9000 lb limit. Anyways what i was wondering is what should i do? i was thinking my only option is to pour a new slab. If that is so, should i just replace the broken slab portion, or should i cut out a certain size portion of the floor and have a single portion of the floor a one piece slab? Im not an expert by any means and could really use some help.

Thanks

 

[lutter94]

Pics will definitely help.

 

[buildingup]

Mostly likely remove the lift, cutout the concrete in the area of the lift and pour thicker to support the manufactures specs.

 

[FordGuy1622]

I will take pictures tonight and post.

So since the hoist is so wide it sits on two separate sections of the floor so you suggest just replacing the broken slab?

Thanks for the responses guys.

 

[going4speed]

Wow even at 2500 psi concrete that should not have happened! Sorry you have to go through that.
I have to wonder what is going on with the subgrade,sub base as well as reinforcement steel used. No matter what that concrete needs cut out to investigate subgrade integrity before a re-pour to me. I'd go 6" 3ksi min. with cross tied rebar. YMMV. Some might say 6" is overkill but if I'm getting under a car on a two post I want a good foundation.

 

[IGOR]

Cut concrete around where hoist should go, dig out like 2 feet, and pour a block of concrete under each leg. Tear out and fix slab as necessary...

 

[kv501]

I take it the post didn't give out with the truck 6' in the air?

 

[jdsac]

Since you have to cut the concrete anyway- the specs from Mohawk if followed exactly would give you a never going to fail floor.
The extra concrete isn't going to add much to the cost.
The ground must be properly compacted also.


http://mohawklifts.com/library/manuals/Slab_Require_Recommend_11_07.pdf

 

[Strouty]

Unless you mix it by hand, more concrete can actually be the same price as less, they usually have a minimum or short load charge.

Sounds like you got lucky no one was hurt, I am curious to see the pictures as well.

 

[Richard Cranium]

It could of been so much worst. As said before cut out the bad area and pour in a thicker piece all the way across.

 

[going4speed]

wow those mohawk guys go above by a large margin. Respect!

 

[Ironcrow]

What failed? I understand that the concrete cracked, but why? Lift post too close to a seam? Concrete actually not thick enough? Anchors improperly installed so only half of them were working? Concrete insufficient psi (will need to core and test)?...

 

[Todd.Brock]

Glad you are ok! The Mohawk guidelines are certainly tall. I would venture a guess they are more stringent than most. I would be really curious about the quality of the area that is keyed into.( existing slab). Would he Mohawk requirements be enough that it would be almost like a stand alone stab holding your lift, thst just happens to be connected to the rest of the floor. Curious to see pics as well as Sub base

 

[rsanter]

You need to figure out the cause. I suspect that the problem is with the ground beneath the slab. Do you have gophers? Shallow water table? Sink hole? Other ground issues?

If it was me I would remove the broken section and inspect below the slab for issues. For the future you need to verify you have good ground. You will likly need to bring in a little rock and do a compaction to be sure you have a good base.
Then I would cut a section out where each of the post feet will be and pour a thicker section that is anywhere from 12x12 to 24x24 and 6" deep depending on what the ground conditions are

Bob

 

[firworks]

If ever a thread needed pictures. Posting so I will check back on this thread later to see the update.

 

[MoonRise]

Pics (just because ).

And then RTFM on floor 'requirements'. The Mohawk PDF referenced above is a good place to look.

Or just look in the manual for the brand and model of lift that you actually have.

Then you (or a contractor that you hire) might have to cut out the 'damaged' section of your concrete slab. Or drill some exploratory holes to check slab condition and the condition of what is under the slab.

And compare your existing slab 'conditions' (thickness? reinforcement? sub-base? proper compaction of dirt under the sub-base? etc) to what you thought should have been there (and what you paid for!).

Proceed from there.

 

[APEowner]

You need to tear out however much of the slab is needed to pour a new one that meets spec. Also, get your truck weighed. My f250 is 8k with half a tank of fuel and me in it.

 

[pstnbly]

Not to point fingers, but improper load placement may be a contributor. I know when I put my dually on my #10,000 lift I make sure the load is centered. I've been using lifts for years and it still makes me nervous. I don't pull on things or load off balance the lift while the truck is lifted without additional support.

 

[Ironcrow]

Eagle Lifts says right on their webpage that if you want to lift an 8,000 lb truck you should buy a 12,000 capacity lift. A poster provided a helpful link in one of the other recent lift food fights. Dunno, I was surprised too. These capacities are "funny" lbs I guess....

 

[Ray916MN]

Gotta find out why the concrete failed to determine what should be done.

4" properly installed concrete should be enough. My floor is 4" with fiber and rebar and I've never had an indication of floor problems using a 9000lb capacity 4 post lift to raise an F250 CC SB diesel.

I'd guess either the pour wasn't done properly or you have a subbase problem. I'd also guess whatever you find, the minimum safe path forward is going to be to cut 4 sections out of the concrete, one for each post, reprep the subbase and pour 4 new pads. If you find the subbase has significantly settled away from the concrete, you're going to have to decide whether you want to try using sandjacking or similar to fill the gap and resupport the slab or whether you want to tear out the entire slab to make sure you fix all the places where the subbase may have fallen away from the slab.

 

[Strouty]

Not funny pounds, but each arm has a capacity and some of the trucks these days, especially diesels can weigh a lot more in the front. 10,000 pound lift is good for 2500 on each arm. If a pickup truck weighs 8,000 you can bet that 2/3 of that is up front.

 

[motofool33]

no pics yet ? wtf?

 

[BillK]

FG,

I did not read all the responses but if it was me the first thing I would do would be to call the lift manufacturer, tell them what happened and ask them to send a representative out to take a look and see if they can determine the cause. They are the experts, not us. They can also tell you the best way to repair the floor.

You don't want to go through all of the process of fixing the floor only to discover that something else caused the failure.

That being said, I bet a Ford F250 is probably pushing the limit on a 9000 lb lift.

 

[Zeke]

Never had a lift. I think having one would be ****, but I don't really need it. So, that having been said, I read lots of posts about lifts. Frankly, I don't think 2 post lifts are very safe w/o special considerations on where and how they are anchored. I know if I ever bought one it would be on 3/8ths steel plates about 3' square and then lagged to the floor.

Being a contractor for 44 years showed me lots of situations. I have never been completely confident with lead shields, Red Heads or even epoxied studs. When I see a public works contractor installing a traffic light or general street lighting, that's what I think of for a lift.

PS, the footings for those are hella stout. Like 3 foot square and 5 feet deep.

 

[BillK]

https://www.eagleequip.com/blog/2013/11/04/car-lift-weights-9k-lift-doesnt-always-lift-9000-pounds/

 

[CJM8515]

A diesel is honestly very front heavy, specially if its a longbed x-cab or crew cab. Id say it was a combination of too heavy a vehicle and likely the ground/slab.

 

[brownbagg]

if I ever had to replace a slab for my lift, i think i would just buy ten tards and dig a hole big enough for ten yard. like somebody said, the extra concrete really not that much. I know it be a big overkill, but its only $800

 

[brownbagg]

Gotta find out why the concrete failed to determine what should be done.

4" properly installed concrete should be enough. My floor is 4" with fiber and rebar and I've never had an indication of floor problems using a 9000lb capacity 4 post lift to raise an F250 CC SB diesel.

because a four post doesnt have the same forces, you could put a four post in a gravel parking lot and have no problem.

 

[Ironcrow]

Never had a lift. I think having one would be ****, but I don't really need it. So, that having been said, I read lots of posts about lifts. Frankly, I don't think 2 post lifts are very safe w/o special considerations on where and how they are anchored. I know if I ever bought one it would be on 3/8ths steel plates about 3' square and then lagged to the floor.

Being a contractor for 44 years showed me lots of situations. I have never been completely confident with lead shields, Red Heads or even epoxied studs. When I see a public works contractor installing a traffic light or general street lighting, that's what I think of for a lift.

PS, the footings for those are hella stout. Like 3 foot square and 5 feet deep.

Yes, this ^^^^^ This site has heaped hate, scorn and derision on me before. I would not generally have a free standing column lift in my garage. If I had this problem to solve (column fell over) I'd pour new concrete, yes, but I'd bury a 10 foot long W16x50 under it and bolt the columns to that.

 

[sberry]

All the folks worrying don't even own one. Millions of cars lifted daily with them.

 

[sberry]

Gotta find out why the concrete failed to determine what should be done.

4" properly installed concrete should be enough. My floor is 4" with fiber and rebar and I've never had an indication of floor problems using a 9000lb capacity 4 post lift to raise an F250 CC SB diesel.

I'd guess either the pour wasn't done properly or you have a subbase problem. I'd also guess whatever you find, the minimum safe path forward is going to be to cut 4 sections out of the concrete, one for each post, reprep the subbase and pour 4 new pads. If you find the subbase has significantly settled away from the concrete, you're going to have to decide whether you want to try using sandjacking or similar to fill the gap and resupport the slab or whether you want to tear out the entire slab to make sure you fix all the places where the subbase may have fallen away from the slab.

This should be repeated as a clear practical post.

 

[sberry]

Yes, this ^^^^^ This site has heaped hate, scorn and derision on me before. I would not generally have a free standing column lift in my garage. If I had this problem to solve (column fell over) I'd pour new concrete, yes, but I'd bury a 10 foot long W16x50 under it and bolt the columns to that.

Why you think this is? This is absolutely amateur.

 

[Ironcrow]

Why you think this is?

I really don't care. At all.

This is absolutely amateur.

Actually, it's not "amateur". This is the sort of thing I do for money.

 

[jask]

This should be repeated as a clear practical post.

Really?... are we dealing with a four post lift here?

 

[theoldwizard1]

Mostly likely remove the lift, cutout the concrete in the area of the lift and pour thicker to support the manufactures specs.

Yeah, like 2-3 feet deep ! Rebar. Set long J-bolts in tied in with the rebar in the pattern to match the holes in the foot of your lift (make a template that you can drop on top to hold them while the cement cures).

 

[James-W]

Really?... are we dealing with a four post lift here?

I had thought the same thing when I read it.

 

[jask]

Why you think this is? This is absolutely amateur.

I would count your opinion as being "absolutely amateur " I have poured enough engineered footings and piers for structures to know you have no idea what you are talking about, and if you had read the above PDF link you would know that the 3/4" wedge anchors they are recommending on an overbuild grade slab are the weak link in any proper install... The OP of this thread needs help not opinion.

OP, the monolithic slab in the PDF above has tons of mass distributed over a wide bearing area- if soil density or saturation is an issue in your area it is the preferred way to go.. pinned to the slab and with the rebar specified. Check with your manufacturer for install info and with that for the price of an hour at the engineers you can avoid guessing.... they will know local soil specs and you can rest easy.

 

[sberry]

I am for some modest overkill if a guy is building but to imply you are so special cause the whole industry is full of idiots and 1000,s of engineers are fools is simply poor advice. I know guys like this. No one knows squat if it was mine I would put in a number 6 wire for 10A load says it alk, would bury beam and add posibly several hundred or more to a common job for every install instead of following some fuggin instruction says it all.
I think you do this sort of thing but not for a living, real customers doing real work would soon find out most of this is half baked. They got a while testing outfit for this to certify these tools. I am of the opinion they pretty much know what they are doing.

 

[sberry]

Neither posted that has a better opinion even bother to find out why.

 

[jask]

I am for some modest overkill if a guy is building but to imply you are so special cause the whole industry is full of idiots and 1000,s of engineers are fools is simply poor advice. I know guys like this. No one knows squat if it was mine I would put in a number 6 wire for 10A load says it alk, would bury beam and add posibly several hundred or more to a common job for every install instead of following some fuggin instruction says it all.
I think you do this sort of thing but not for a living, real customers doing real work would soon find out most of this is half baked. They got a while testing outfit for this to certify these tools. I am of the opinion they pretty much know what they are doing.

After you have coffee in the morning you might want to delete this nonsense...