2 post lift install -- documented

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Righty Tighty

Blame it on the dog
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I posted a thread here a while back asking for advice from those who've installed lifts. This thread is a follow up and will document the installation process.

I got a ton of great feedback in the first thread and purchased a used 12,000lb two-post. It was one of a few in a small professional shop and when they moved, didn't fit in the space they had. The owner had the lift disassembled by the same company that installed it, and I'll have that company install it at my shop.

I've learned that the most important part of a lift installation is the concrete slab. Thickness is crucial, and PSI rating of the concrete also very important. So, the landlord and I drilled the slab to confirm thickness prior to starting, and it is 4". The manufacturer of this lift requires a minimum of 6", 3000 PSI concrete, so I will be cutting the slab where the lift will be and pouring a thicker pad.

The installer recommended 4' x 4' x 12", so that's what I'm going to do. Yes, 12" is double what the manufacturer requires, but if I'm cutting the slab anyway, I would MUCH prefer overkill over cutting corners.

Stay tuned for pictures and more updates on the progress. As always, I'm open to tips, suggestions, advice, criticism. This thread is intended to help others as well as help myself...
 
When I installed my two post I didn't use epoxy on the anchors down in the concrete. So the anchors took some tightening for the next two or so years then finally locked into place. When I had garage built I had them put down 3000 PSI concrete 6 inches thick but it seemed a lot thicker when I drilled for the anchors.

Other challenge I faced was cracks in the floor that showed up shortly after garage was built. But they are far enough away from the anchors to be safe. Lift has been installed around 10 years now.

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One of my posts ended up right beside the cut lines in my floor so I built a top truss and post braces so I wasn't playing Russian roulette..

Still ticks me off my Son didn't hang onto those "fluke" plates when he totaled that car.
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Dang right, bud! Overkill is the way to go when you're talkin about a lift. You got your head on straight about it!
 
I would think that you would have to pin those new slabs into the old slab with re-bar. Just thinking out loud.
 
When I installed my two post I didn't use epoxy on the anchors down in the concrete. So the anchors took some tightening for the next two or so years then finally locked into place. When I had garage built I had them put down 3000 PSI concrete 6 inches thick but it seemed a lot thicker when I drilled for the anchors.

Other challenge I faced was cracks in the floor that showed up shortly after garage was built. But they are far enough away from the anchors to be safe. Lift has been installed around 10 years now.

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Thanks for the input. The slab I’m dealing with was poured in the 80s, and there are just a few tiny cracks and are far away from where the anchors will be. Doesn’t matter in my case though, because I’ll be pouring new footers.

I don’t know if the installer will be using epoxy or not, maybe I should ask.
 
I would think that you would have to pin those new slabs into the old slab with re-bar. Just thinking out loud.
Yes, absolutely!! I will be digging down 8 more inches below the 4” slab, then a few inches under the slab in each direction, and drilling for rebar. I will epoxy rebar into the existing slab every 8” to make a grid, although I haven’t decided the size of rebar I will need.
 
After verifying tab thickness, I found the center of the opening of the bay. Then I used a laser level to bring center back to where the lift will be. I used the expansion joint as a reference for squareness. (I know, that's not really an expansion joint.)
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I'm watching this thread for sure. I'm going to be doing this in the spring. Building a steel building because wood prices are crazy! 24x30 Building is ordered and should be here in a few weeks... I hope the weather holds out! I went with 6" of concrete. They told be 4" min also but I didn't like the sounds of that. I would have gone 7" but concrete is not exactly cheap. Foundation is done... playing the waiting game.
 
I have a condo with poured concrete basement walls. They are cracked and required repair. This is what I have learned by scouring the internet and talking to a few contractors. My condo foundation was poured in April (windy) and the floor shortly after. High strength concrete ( high psi rating) is mix with less water. More water the weaker it will be. Less water stronger it will be and also it sets and cures faster causing more heat. This expansion and contraction causes cracks. One contractor showed me a step on a walkway he poured that exploded while setting cause it got too hot. The trick is to keep it as cool as possible while setting and hydrated while curing which takes about 3 weeks. In San Francisco they fill foundations with water after the set till its cured for earthquake strength. Also my floor has voids in it from poor compacting the substrate before the pour and maybe ice. Both in the basement and garage, I can stomp on the floor and hear hollow if places. It’s only 4 inch thick 300 psi slab. It has not cracked or broken even in the garage with a car parked on top. Its a strong slab and its no joke.
 
Here was my layout........You can see the pads where the hoist went. I also installed rebar shaped like a hockey stick that turned down into the deeper section.

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Laid out the 4’ x 4’ squares where the feet will be, marked with a paint pen so it won’t wash away with the water from the concrete saw.
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Concrete saw made easy work of the slab, now it’s time for the real work to begin with the sledge, jackhammer, pry bar, etc.
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With the help of a 10lb sledge, a digging bar, and a jackhammer, was able to remove the concrete.
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Today, I'll dig the dirt down 8 more inches to give a total of 12" depth and drill for rebar if there's time.
 
That sledge hammer is too much like work. A GOOD air chisel would have made quick work of that.
 
Now ya tell me, lol. I do have an air chisel but it didn't occur to me to use it. Originally, I tried busting it up with the jackhammer, but it was taking forever and the concrete was just pulverizing. Yes, using that sledge was a ton of work, but I was able to get out some pent up aggression, so I got a neat little therapy session out of it.
 
Nice job...It looks good.

BTW, Love the Avatar........"Looks like I picked a bad day to quit sniffing glue"
 
Did I read that correctly, you are renting this place and doing the work with the land lords consent ?

that sounds like a pretty cool land lord
 
So I know nothing about lifts, but I see people doing what you do a lot to install them. My question is, why not just remove the piece of concrete between the feet pads? Like a big rectangle of concrete so the new thicker part is the entire width instead of just under the lift feet? Wouldn't that also be stronger with less likelihood to shift in relation to the old slab?

Either way, nice work, my garage would have everything coated in concrete dust if I were to do that job!
 
So I know nothing about lifts, but I see people doing what you do a lot to install them. My question is, why not just remove the piece of concrete between the feet pads? Like a big rectangle of concrete so the new thicker part is the entire width instead of just under the lift feet? Wouldn't that also be stronger with less likelihood to shift in relation to the old slab?

Either way, nice work, my garage would have everything coated in concrete dust if I were to do that job!
I agree, what you say makes good sense. To be honest, I’m doing it this way because that’s what the installer said to do. He’s the pro, so I’m following his directions to the letter. Maybe doing it this way is plenty strong/stable enough and saves money? I really don’t know.

And trust me, there was plenty of dust!!
 
As long as it's tied in solidly to the original slab I think it would be fine. Having said that, I would be considering going a couple feet down and using sonotubes for a bit more peace of mind, but that's just me.
 
I agree, what you say makes good sense. To be honest, I’m doing it this way because that’s what the installer said to do. He’s the pro, so I’m following his directions to the letter. Maybe doing it this way is plenty strong/stable enough and saves money? I really don’t know.

And trust me, there was plenty of dust!!


I agree, if the installer said to go that route, it makes sense to do it that way. I was just asking the question, that's all.
 
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