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Leveling concrete mix

493 Views 24 Replies 7 Participants Last post by  Matt1963
I’m rearranging my garage shop to park a car out of the hot sun and blowing sand, but I ran into a concrete problem. I never really noticed it before but I have a section of concrete that looks like they were short of concrete mix and it is not level or smooth. I have a large very heavy tool cabinet that has to go there, but the area is so bad the cabinet wobbles on 3 wheels.

I have some concrete leveling mix, but it doesn’t look like its strong enough to support the weight. The tool cabinet has to weigh well over a 1000 lbs and maybe even up to 1500 lbs on 6 wheels. If the section was smooth, I would just shim each wheel up with something. So, my question is will leveling mix be able to support the weight?
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· Naildriver
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It would go a long way to grind that area free from boogers. You may find it smooth enough without adding SLC to it. But if you do, it will do a good job and will handle the tool box. Must have been end of day on Friday when the poured :eek:
 

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I have some concrete leveling mix, but it doesn’t look like its strong enough to support the weight.
Why do you say that ? (other than perhaps it's been sitting around in an opened bag too long)
What is the strength of your levelling mix ?
If the cured strength is not on the bag, than it will be on the product specs on the web-site.
Your garage floor is probably 3000 psi to 3500 psi.
 

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Discussion Starter · #4 ·
Why do you say that ? (other than perhaps it's been sitting around in an opened bag too long)
What is the strength of your levelling mix ?
I say that because I hired a guy who was supposed to have 10 yrs experience pour me a concrete slab for a new work shop and it got away from him. There were huge holes and deep boot print all over it. He tried fixing it with some sort of leveling mix, but it never got hard and the wheels of my hand truck would sink right in while carrying anything heavy. I had to dig it all out and hire another guy to pour concrete over it.
 

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Can't say why you have had so many mistakes but all levelers and patching compounds should be plenty strong.

Being a garage, the slab should have some slope on it so you will need a trowel down product of some kind. Self leveler probably won't work in this case.
 

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Mapei self levelling compound is 4200 psi. Other brands probably similar. Stronger than the base concrete, in all likelyhood.

Its only two feet wide, so does not need much slope. And to the dismay of any rookie who has tried to put down self levelling compound, it really does not self-level. It needs help.

On that little area, OP could possibly be the first person on this forum who could say on his first attempt he levelled it out nicely before it set. :)

Possibly needs a primer over the old concrete.

But you might want to mix a small sample and check the color match. A lot of patches are pretty dark. Last time I had to fix up a damaged floor, I used a patching concrete patch compound but had to mix in some titanium dioxide (white pigment) to get the color right.
 

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Discussion Starter · #8 ·
Can't say why you have had so many mistakes but all levelers and patching compounds should be plenty strong.

Being a garage, the slab should have some slope on it so you will need a trowel down product of some kind. Self leveler probably won't work in this case.
This section is 3" above the garage floor. I had to remove all the tools and drawers just to get it up on the level part. My 1 ton floor jack was struggling to even pick it up so to be on the safe side, I just pull everything out of it
 

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Can't say that self leveler will not work, when it may have been a beer o'clock installer on a Friday at 5pm, who did no prep work, did not read the instructions and just poured self-leveler over a dirty and dusty surface.

Against the wall like that, or for a workshop area, wanting something flatter & easier to clean; I would try my hand at grinding down the high spots, thoroughly steel brushing, washing, drying, priming and then a bag of self leveler.

But, maybe you don't need leveler. Maybe with just grinding that section smooth, to something flat, and feathering it with the rest of the garage area ... it'd be good enough. Could rent a concrete floor grinder at a local rental yard, resurface the top bit of the whole garage :)
 

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This section is 3" above the garage floor. I had to remove all the tools and drawers just to get it up on the level part. My 1 ton floor jack was struggling to even pick it up so to be on the safe side, I just pull everything out of it
So to be clear, you have a raised 3 inch concrete pad higher than the floor that was supposed to be level for tools and such?

Most products want you to put a primer down to get a better bond and to increase their profit margins!

If the above is true than the overlay (not underlay) will be an easier product to use for a DIYer.

Just follow the bags instructions.
 

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Discussion Starter · #13 ·
This is a photo of what the floor actually looks like. The tool box is so heavy when its full that I can barely move it on a large surface so it's never going to roll anywhere. I just want all the wheels to be on a level floor so that nothing sags or distorts.
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Discussion Starter · #16 ·
Nice Cabinet
This is why 3 legs were invented because 4 won't set without rocking 99.9% of the time , 6 would be a nightmare and you would likely need to shim for final satisfaction so just shim it as is and lever as in lever alone .
Thanks! I’ve never taken a vehicle to a mechanic in my life except for tires and front-end alignment. Where I came from auto mechanics were not to be trusted under any circumstance so when something broke I bought the tools and learned to fix it myself. Now I have enough tools to open my own auto shop business. I had always hoped me son would go into business with me some day, but he made a career out of the military instead.
 

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Thanks, I think I'm going to buy a new box or bag.
What do you mean by primer? I never heard of that before
If you read the directions on Mapei self levelling compound, they say to prime concrete with Mapei Primer T.

If you are using just concrete patching compound, use something like THIS bonding agent. A lot of times, I will use the bonding agent instead of water to mix the concrete.
Of course you floor has to be clean, but best that it is best to soak the old concrete before laying the patch on. Otherwise, the dry old concrete will pull the water out of the patch very quickly.

Storm is moving through right now. Just as I was about to post the above, power went out. But I got lucky, when power came back on, I restarted my computer, and "restore open web pages" and it even saved what I had typed.
 

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A yes.....it's called moose milk in the industry. Put it in wrong and it's a bond breaker.

Concrete looks fresh and quite rough so should bond well.....not sure you will need that.

If you decide on the slc....you will want to cut the edge a 1/2 or so, chip it out and pour against that.

That's why I recommended the feather finish.
 
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