Lift Install safe?

[StevenS]

Hello Everyone! First Post. Great place here. Been reading for a long time figured it was time to join.

So this like has been here for years. I have lifted many cars and trucks. 8000lb lift in 6 inches concrete. I have 10 foot ceilings so the lift has never been more then half way up. Now its time to open up the ceiling and raise it so i can get cars up higher. But now with the cars going up all the way will i have a problem with the saw line thats next to the lift base?

thanks for your help.

 

[AC-WC]

Everything I've ever read on lift placement you're not supposed to be any closer than 6-8". That's where mine are. Is it both posts or just 1? Personally I would bite the bullet and start cutting concrete.

 

[ericm]

The manufacturer should have a spec for how close the lift can be to saw cuts and joints. I don't know how the extra angle iron affects that.

 

[StevenS]

Yea thats what I thought. But it is only a saw cut and its not deep. So I dont know. Kind of *****.

 

[StevenS]

I will see if I can find specs.

 

[wssix99]

Yes. You've also had a problem up to this point. All the bolts that are near that crack (probably within 8-10") only have a fraction of the pull-out strength intended. (The joint makes the concrete weak.)

 

[mike93lx]

Yea thats what I thought. But it is only a saw cut and its not deep. So I dont know. Kind of *****.

The saw cut is there to allow the slab to crack in the bottom of it. It significantly weakens that location

 

[StevenS]

So I should move the lift. I could put the wider door in and move it over a foot But how far forward would it need to go?.

 

[dante2]

Do you have enough room to move it a foot north or south from the cut?

 

[StevenS]

Do you have enough room to move it a foot north or south from the cut?

No I have about 6 inches but if I put the wider door in I could move it 12 inches west and 6 inches forward away from saw cut. But I have a shop with welder. Why cant I just weld a 12 inch plate on to the base and anchor that in the concrete behind the saw cut.

 

[firebirdparts]

Time will tell, I guess, but the extender bar on that helps a lot. In a sense you've already got it beefed up. Feel free to weld on more stuff. Feel free to brace it from the building if you have anything substantial to hook to.

The forces on it are not huge compared to the force you can put on it just by torqueing. You can load test it just by how tight you've got it torqued down. I need to do some math on that sometime.

 

[StevenS]

Time will tell, I guess, but the extender bar on that helps a lot. In a sense you've already got it beefed up. Feel free to weld on more stuff. Feel free to brace it from the building if you have anything substantial to hook to.

The forces on it are not huge compared to the force you can put on it just by torqueing. You can load test it just by how tight you've got it torqued down. I need to do some math on that sometime.

The lift has been there for years in front of that saw cut. Fasteners are tightened to 120 ft lbs. I check them from time to time but they have never come loose and I had super dutys on it for weeks at a time. But as I said it only went up halfway with 10 foot ceilings. I always center the vehicle on the lift before I pick it up. I am more worried about the lift pulling inward forces then front to back. When I put heavy weight on the lift I can see the uprights pull in. I wish it had a top beam across the top.

 

[KSJeff]

No I have about 6 inches but if I put the wider door in I could move it 12 inches west and 6 inches forward away from saw cut. But I have a shop with welder. Why cant I just weld a 12 inch plate on to the base and anchor that in the concrete behind the saw cut.

That is probably what I would do. I might put in some gussets if it wouldn't be a major trip hazard but that's probably overkill. Good luck.

 

[StevenS]

That is probably what I would do. I might put in some gussets if it wouldn't be a major trip hazard but that's probably overkill. Good luck.

You saying you agree with the plate idea. That would be great. The lift is in the perfect spot right now.

 

[KSJeff]

You saying you agree with the plate idea. That would be great. The lift is in the perfect spot right now.

Yep, that's probably what I'd do. But, I went to welding school and I'm pretty confident with my ability to evaluate the weld. If you are too, then I'd certainly start there and see how it does.

 

[StevenS]

Yep, that's probably what I'd do. But, I went to welding school and I'm pretty confident with my ability to evaluate the weld. If you are too, then I'd certainly start there and see how it does.

My son is a certified welder and works at a metal fab shop.

 

[kbuhagiar]

My son is a certified welder and works at a metal fab shop.

There you go!

 

[KSJeff]

My son is a certified welder and works at a metal fab shop.

Sounds good. Just get it good and clean, bevel the edges and weld it in.

***Also, I can't see how thick that metal is, but you might see if he wants to weld in a fish plate on top of that. Probably overkill but it won't hurt anything.

 

[ericm]

Yea thats what I thought. But it is only a saw cut and its not deep. So I dont know. Kind of *****.

The point of the saw cut is so the slab will crack at the cut in a controlled fashion instead of randomly. You probably can't see in there but I'd assume that it's cracked at the cut.


If the install does not meet the manufacturer's specs the safest thing would be to cut out the concrete around the lift and put in a new piece that meets the lift manufacturer's specs for doing that. Usually the new chunks are deeper and need to be tied into the existing slab with pins. But that way you could keep the lift in its current position and not be worried about it falling. With a backyard engineered solution you will always be wondering if it's sufficient.

 

[afazz]

Lifting vehicles higher will not result in greater forces on the anchors or concrete.

 

[mike93lx]

Lifting vehicles higher will not result in greater forces on the anchors or concrete.

You sure about that? The columns on a 2 post pull inwards, putting a lifting force on the outside anchors and as the lift gets higher, the lever becomes longer

 

[StevenS]

You sure about that? The columns on a 2 post pull inwards, putting a lifting force on the outside anchors and as the lift gets higher, the lever becomes longer

Agreed and thats my worry.

 

[afazz]

The moment arm length, the distance perpendicular do your forces (vehicle pushing down on the arms, plates bearing down on the concrete, loads pulling on the anchors), remains unchanged. This is neglecting deflection of the column, but that’s on the order of 1/16” and the arms can be 48” or more.

 

[StevenS]

Well I have to say. My lift is for low ceilings. The lift cyls that go up thru the ceiling as the lift goes up. I can see the cyls move inward as the lift goes up. The heavier the car the more flex it has..So IMO if they move in more when the lift goes up would mean there is more force on the anchors to flex that steel.

 

[Jagmandave]

So, why not put a bar across the top?

 

[StevenS]

So, why not put a bar across the top?

Not high enough. You need at least 12 feet. This is not even 10 feet. There are many lifts out there with no top bar. Lets you get higher top vehicles up.

 

[StevenS]

So I was checking out the base on the lift. I found that the bottom plate is 5/8 inch steel. The side piece that looks like angle iron is 1/2 inch steel. So if I weld a 5/8 plate to each backside that would put the anchors out 12 inches from the saw cut. I think that would give me a wide footprint and a very strong one too. Like I said it been there for years with many lifts. Never loose or cracked.

 

[Al G]

The correct answer has been stated a few times - follow the manufacturer's requirements for placement. Pouring a new footing is probably the best way to achieve that. Yet you seem to have made up your mind that you can do some reinforcement hack. Why bother to ask? It's your life.

 

[Al G]

Well I have to say. My lift is for low ceilings. The lift cyls that go up thru the ceiling as the lift goes up. I can see the cyls move inward as the lift goes up. The heavier the car the more flex it has..So IMO if they move in more when the lift goes up would mean there is more force on the anchors to flex that steel.

Maybe it's flexing because the anchors aren't as secure as you think they are?

 

[StevenS]

The correct answer has been stated a few times - follow the manufacturer's requirements for placement. Pouring a new footing is probably the best way to achieve that. Yet you seem to have made up your mind that you can do some reinforcement hack. Why bother to ask? It's your life.

Why the smug answer. No I did not make my mind up. No I dont have to pour a pad. I can move the lift if need be, Just asking for ideas.

 

[StevenS]

Maybe it's flexing because the anchors aren't as secure as you think they are?

Lift has been in operation since 2017. I think if there was anchor issue it would of shown by now.

 

[Wrench97]

Lift has been in operation since 2017. I think if there was anchor issue it would of shown by now.

Anchor issue will show up with heavy use, large truck, lot of pushing and pulling etc.
My lift at work loosened up and the fix was to cut a 2.5' x 2.5' x 2' deep section under both posts and repour then reset the lift took about a month to get it completed.

 

[Jagmandave]

I've seen people extend the vertical posts and anchor them to a girder or something in the ceiling to help stop the "flex".

 

[StevenS]

Thanks everyone for all your help. Since I have the new truss in my ceiling and have ceiling height now. I may just buy a new lift. 12 footer with the top beam. relocate lift and be done with it.

 

[CraigStu]

2 thoughts. 1- I liked the Q about moving it north or south. What I took from that was I would move it toward the top of your picture. Depending on the type of anchors used I'd re-use the anchors that we can't see for the bolts we can see and then drill new as needed. 2- I disagree that raising a vehicle higher will not increase the load on the anchors. Think of trying to remove a post that has been in the ground for a while. Are you going to grab it at 2ft off the ground to try to pull it sideways to start loosening it? Or are you going to grab it as high up as you can? I know that grabbing it as high as I can will be more effective at moving the post or at pulling the anchor bolts out of the floor/cracking the concrete.