Lift & expansion joint

[cartunes]

Was getting ready to order a Bendpak XPR-10C lift, when I came to the realization that the guy who poured the floor cut an expansion joint right through the middle of the bay where the lift will go. So looks like the lift pads would be right over the cut. I assume this is not acceptable?
I'm meeting with the lift distributor/installer tomorrow, will ask him the same question.
If I have to cut/chop that section of floor out, what pattern do I need to follow?
Thanks

 

[kool55]

Is your expansion joint cut the full depth or just a slight cut for a potential crack to follow? If its where the lift pads are you are still 48''+or- from the column bases.No?

 

[cartunes]

The cut is about 3/4" deep, floor is 4" thick. I misspoke above, its right where the bases would bolt down.

 

[ket-tek]

Bendpak specs out to be 6" from expansion joints. Being only 3/4" deep cut though I'm not sure. Probally want to call bendpak directly and ask them.

Will the column bases be right up next to the cut or span over the cut?

 

[BoostedOne]

Bendpak specs out to be 6" from expansion joints. Being only 3/4" deep cut though I'm not sure. Probally want to call bendpak directly and ask them.

Will the column bases be right up next to the cut or span over the cut?

Does Bend Pak even recommend a 2 post lift on a 4" slab?

I contacted a lift guy regarding my lift, and he said 8" thick 4500psi concrete in the area of the lift... The guy I got the lift from(who bought it new) said 6" thick, and the anchors for the size bolts it use I think have to go 6" to seat in the concrete.

I dont know if you could pay me enough to stand under a 2 post on a 4" slab of unknown strength concrete with unknown reinforcement.

If it was only a 4" slab, I would go with a 4 post..

 

[ket-tek]

For the 10,000lb models they recommend 4" 3000psi according to page 7 of the installation manual.

http://www.bendpak.com/XPR10-Series-Manual-REVC.pdf

Of course thicker and stronger is better.. The key is verifing that the floor is actually uniformly 4" thick as it can easily vary through-out the slab.

 

[cartunes]

I have 4" of 3500psi.
The base plates will probably span the joint.
I'll call Bendpak later today.
Thanks

 

[BoostedOne]

For the 10,000lb models they recommend 4" 3000psi according to page 7 of the installation manual.

http://www.bendpak.com/XPR10-Series-Manual-REVC.pdf

Of course thicker and stronger is better.. The key is verifing that the floor is actually uniformly 4" thick as it can easily vary through-out the slab.

Hmm, maybe I am going to be severly overdoing my slab then? The lift i have is by a company called Baymaster which isnt in business anymore so I cant go to them for help.... Since money is definately not no object, Id rather not go too overboard.

 

[BoostedOne]

Hmm, not tryin to hijack the thread but after searching it appears it might be a Ben Peason since Ben Pearson has a baymaster line..... The tag on it said "Baymaster Lifts, Ft Worth Tx" and thats it.... Gonna call Ben Pearson when I get off this conference call for work and figure out if they may have bought out this company or if it. The pics on their website sure look like it from the low quality pics they got...

 

[ket-tek]

Hmm, maybe I am going to be severly overdoing my slab then?

You can always dig down under where the 2 columns will be set, and pour footers 12" or more deep just for the columns, and get the rest of the slab poured as normal. And not increase the cost much more than a standard home garage pour.

Other than a for a large lift or frame pulling hooks in the floor, having more than 4"-6" in a home garage is probally a bit overkill. I had 6" done for mine, just thinking that even if there were thinner spots I should have a solid 4" everywhere still.. (the cost difference was minimal, as I was building the house and garage at the same time)

 

[BoostedOne]

Well, I called Ben Pearson when I got off the phone. Ben Pearson bought this company called Baymaster out of Ft Worth in he mid 90s. Then had knockoffs made of those lifts in China. So while the current Ben Pearson Baymasters are chinese, since I have a genuine Baymaster, its actually and american made lift, so thats pretty cool.

Anyhow, to the point of the conversation here, he said a 4" slab 3500psi is the minimum. He said going thicker is far from a bad idea though, since the 4" is just what most people already have and it works. But with a new floor, he says alot of times what he does is dig out a trough 24" wide and 2 feet longer than the foot print of the lift, and do that 6-8" with some rebar. That way there is plenty of thickness for the anchors and so forth to bite into.

My slab is going to be 35x60 overall, so its already expensive enough for me.

As for pulling hooks, I wish I had them when I was doing alot of work out of my old house garage, but once I moved into my shop I never thought about it again since it was a drive through configuration. I just bought a new place and its got a pole barn on it that I am going to enclose and set up the same way.

 

[nate379]

I would not think so! I wouldn't even consider a 4" slab in just a shop, never mind one with a lift!

On a 35x60 that is roughly a $1000 difference between a 4 and 6" slab. Money well spent IMO.

Does Bend Pak even recommend a 2 post lift on a 4" slab?

I contacted a lift guy regarding my lift, and he said 8" thick 4500psi concrete in the area of the lift... The guy I got the lift from(who bought it new) said 6" thick, and the anchors for the size bolts it use I think have to go 6" to seat in the concrete.

I dont know if you could pay me enough to stand under a 2 post on a 4" slab of unknown strength concrete with unknown reinforcement.

If it was only a 4" slab, I would go with a 4 post..

 

[cartunes]

I called Bendpak. The guy I spoke with didn;t know the answer, he's gonna reach out to his coworkers and get back to me.

 

[royale5]

The cut is about 3/4" deep, floor is 4" thick. I misspoke above, its right where the bases would bolt down.

This type of joint is called a "control joint" not an expansion joint. They are 2 totally different things. A control joint is a sawcut used to help control where cracking occurs.

An expansion joint is a break between 2 pours with some type of expansion space typically 1-2" wide that would require a cover plate.

I wouldn't be too concerned with the floor moving at the sawcut. As long as the concrete came up to the 3000psi you should be OK.

 

[cartunes]

Got this from Jeff at Bendpak:

The base plates are designed with four anchor holes towards the rear backside edge and two anchor holes towards the front edge, one positioned at each of the front corners. The two front edge (or anchor holes closest to the lifting arms) are not as important as the rear anchors as there is little moment loading. You need to position the rear anchors no closer than 6" away from any crack or joint. It is OK to straddle the crack as long as you maintain the 6" spacing on rear anchors.

 

[94cobra2615]

Got this from Jeff at Bendpak:

The base plates are designed with four anchor holes towards the rear backside edge and two anchor holes towards the front edge, one positioned at each of the front corners. The two front edge (or anchor holes closest to the lifting arms) are not as important as the rear anchors as there is little moment loading. You need to position the rear anchors no closer than 6" away from any crack or joint. It is OK to straddle the crack as long as you maintain the 6" spacing on rear anchors.

Exactly what the manual for my lift says.

Also, What is the difference between a sawcut control joint that is 3/4" deep and cracked the rest of the thickness down --and-- a control joint that is sawed all the way through the concrete?

 

[timewarp]

Exactly what the manual for my lift says.

Also, What is the difference between a sawcut control joint that is 3/4" deep and cracked the rest of the thickness down --and-- a control joint that is sawed all the way through the concrete?

If it was sawed all the way through the concrete it will be a straight cut and could move, if it cracks on it's own the rest of the thickness the crack isn't smooth so the pieces should still be keyed into each other so if one tries to move up or down the other will have to go with it, especially if you have a steel plate bolted over the top of the crack which won't allow the two sides of the crack to seperate very easy.