How can I fix this slab

[thejudges69]

I didn't notice all this til last night when the floor was wet and headlights hit it. It looks like Ray Charles and Hellen Keller finished it. The floor is an absolute washboard. The floor is 20 ish days old, not sealed yet. Can I rent a sander or buffer and correct any of this? I haven't met with the builder yet, but the unfortunate part is that I'm on a time crunch. It was 85 degrees when we poured and I'm thinking the concrete was drying faster then they could finish it.

Any input?

 

[Shiftless]

How big is that slab?
Was the contractor licensed?
Did you pay 100% yet?
What is the reason for the time crunch?

 

[thejudges69]

Did you pay 100% yet?

That's really irrelevant to the thread. Any input on fixing it?

 

[Shiftless]

The reason I asked is that if the contractor hasn’t been payed you have more leverage in getting him to fix it.

You might be able to grind it to minimize the variations, but as others will probably say, the best fix is to tear it out and repour.

There was an old slab in my back patio that was rough. I applied a thin overlay which has held up to foot traffic for the past year. I’m expecting it to flake off in places over the coming years.
But it‘s only about 8x8 feet.

 

[thejudges69]

The reason I asked is that if the contractor hasn’t been payed you have more leverage in getting him to fix it.

You might be able to grind it to minimize the variations, but as others will probably say, the best fix is to tear it out and repour.

I'm aware of all of that. I didn't ask any my payment method. Tearing it out and repouring is not an option with my time frame. I need to minimize what's there. So as my initial question was ask, how can I fix it.

 

[Shiftless]

There are products to do a thin overlay. Ardex comes to mind. I have no experience with that stuff. I’m by no means a concrete guy.

 

[ConCretin]

First off, the reason you didn't notice it before is you never shined headlights across it at a low angle. Every flaw is magnified tremendously under these light conditions. There are a couple minor issues that could be addressed but I don't see anything to justify 'tearing it out'. Any patch or overlay is going to look worse than the problem and be a durability concern. You could run a floor grinder over it to smooth it up a bit but I'd just move on and enjoy the new shop.

For reference, there is no such thing as a perfectly flat floor. A good floor will show 1/4" gaps under a 10' straightedge. A really good floor might have gaps closer to an 1/8" Water will birdbath on every floor ever poured if it isn't sloped a lot enough to shed the water.

 

[thejudges69]

First off, the reason you didn't notice it before is you never shined headlights across it at a low angle. Every flaw is magnified tremendously under these light conditions. There are a couple minor issues that could be addressed but I don't see anything to justify 'tearing it out'. Any patch or overlay is going to look worse than the problem and be a durability concern. You could run a floor grinder over it to smooth it up a bit but I'd just move on and enjoy the new shop.

I know your right, however it doesn't look much better without the lights during daylight. I don't think and overlay would be a good fix for this size slab. How much difference would a grinder make?

 

[nmk_61802]

Racedeck or hire a flooring company to grind and epoxy

 

[thejudges69]

Racedeck or hire a flooring company to grind and epoxy

4800 sq ft is a lot of racedeck . I have an floor company coming Monday to give their opinion.. I was curious if I could fix it..but sounds like I don't have the expertise or tooling.

 

[nmk_61802]

4800 sq ft is a lot of racedeck . I have an floor company coming Monday to give their opinion.. I was curious if I could fix it..but sounds like I don't have the expertise or tooling.

First time I believe you have mentioned size in the thread....hence the two options. Racedeck is easy if not cost prohibitive. Grinding will remove the high spots and "normalize" the floor, but will remove any finish/ polish on those spots, so you need to top-coat.

 

[thejudges69]

First time I believe you have mentioned size in the thread....hence the two options. Racedeck is easy if not cost prohibitive. Grinding will remove the high spots and "normalize" the floor, but will remove any finish/ polish on those spots, so you need to top-coat.

I have a building thread, just haven't updated it cause it didn't show interest. I'm reading I can have it polished to 800-1000 grit with a diamond polisher to refinish it, is that correct? The floor is just raw concrete, no sealer or paint

 

[Shiftless]

Grinding it flat and polishing will definitely fix the problem and end up looking great. It might cost in the neighborhood of $20,000++ though…

 

[thejudges69]

Grinding it flat and polishing will definitely fix the problem and end up looking great. It might cost in the neighborhood of $20,000++ though…

That's a pile of money, the slab alone was that much to pour. How accurate is that number or is that simply a guess?

 

[Shiftless]

Just a guess. There are lots of variables of course. Call around and see if any experienced companies can come out to give you an estimate.

Here is a link

Polished Concrete Floor Cost - How Much to Grind Concrete? - Concrete Network

Information about the cost of polished concrete and what price to expect when installing polished concrete.

www.concretenetwork.com

 

[thejudges69]

Just a guess. There are lots of variables of course. Call around and see if any experienced companies can come out to give you an estimate.

Here is a link

Polished Concrete Floor Cost - How Much to Grind Concrete? - Concrete Network

Information about the cost of polished concrete and what price to expect when installing polished concrete.

www.concretenetwork.com

I'm curious is they can just high grit finish it, like 800-1000 grit to fix some of what's there.

 

[Shiftless]

I'm curious is they can just high grit finish it, like 800-1000 grit to fix some of what's there.

Only an on site inspection by a knowledgeable and competent specialist can answer that question. Seems to me if you only polish part of the slab, or just the high points, it will give it such an uneven appearance you’ll be even more dissatisfied.
Think about where you’ll put stuff once the garage is filled. Maybe with all your stuff in there, it won’t seem so bad.

 

[thejudges69]

So can someone explain. I have a company locally that thinks he can fix this for a good cost. He's saying likely grind it with 40,80 and final with 100 grit.

Will 100 grit leave a smooth surface? I told him I don't need it polished just smooth to work on and sand.

Here are some daytime shots.

 

[thejudges69]

Couple more

 

[bigjon]

100 grit looks smooth but the concrete will soak everything you spill on it i.e. oil, brake fluid, etc… Maybe look at applying a topical sealer after to protect it. The vendors here have tons of options depending on budget.

 

[thejudges69]

100 grit looks smooth but the concrete will soak everything you spill on it i.e. oil, brake fluid, etc… Maybe look at applying a topical sealer after to protect it. The vendors here have tons of options depending on budget.

We're checking to make sure I can still put my densifier on it after we grind. It doesn't have any sealer on it now.

 

[FMB4]

How big is that slab?
Was the contractor licensed?
Did you pay 100% yet?
What is the reason for the time crunch?

That's really irrelevant to the thread. Any input on fixing it?

No, the questions are very much relevant to your post. That's a hugely botched pour that will likely cost you more to 'fix' to an acceptable degree than what you paid for the job. Imo, you'd be far better off by insisting that the concrete con you hired tear it out, free of cost, so you can have a licensed, insured, and bonded contractor pour it correctly. Meanwhile, I trust that you didn't pay much for that pour.

 

[thejudges69]

No, the questions are very much relevant to your post. That's a hugely botched pour that will likely cost you more to 'fix' to an acceptable degree than what you paid for the job. Imo, you'd be far better off by insisting that the concrete con you hired tear it out, free of cost, so you can have a licensed, insured, and bonded contractor pour it correctly. Meanwhile, I trust that you didn't pay much for that pour.

Welp tearing it out isn't an option. The installers we're licensed and insured but again, tearing it out isn't an option and I doubt most would push for that or allow that. Talk a big talk, but walking it is another question. I'm still on a time crunch and I don't have that kind of time..

 

[ConCretin]

I love the "make the guy rip it out and pour a new slab" posts that inevitably pop up in these threads. Your slab doesn't warrant replacement anyway but that ain't gonna happen.

There are some aesthetic issues with your slab but I've seen much worse. As much as it annoys you now, I suspect once you move everything in and go to work, you'll hardly notice. With that said, I think you are on the right track with a light grind. It will smooth things up and should cost a lot less than a full blown polish, which starts with an aggressive grind that removes a significant amount of material before a multitude of passes to get to a gloss finish.

For what you need, we've actually had some success with a standard floor buffer with weights and diamond discs. Hopefully you can find someone to do something similar for a reasonable price. I don't think its too much to ask for your contractor to participate in the cost of the repair. Good luck with this and the rest of the build.

 

[thejudges69]

I love the "make the guy rip it out and pour a new slab" posts that inevitably pop up in these threads. Your slab doesn't warrant replacement anyway but that ain't gonna happen.

There are some aesthetic issues with your slab but I've seen much worse. As much as it annoys you now, I suspect once you move everything in and go to work, you'll hardly notice. With that said, I think you are on the right track with a light grind. It will smooth things up and should cost a lot less than a full blown polish, which starts with an aggressive grind that removes a significant amount of material before a multitude of passes to get to a gloss finish.

For what you need, we've actually had some success with a standard floor buffer with weights and diamond discs. Hopefully you can find someone to do something similar for a reasonable price. I don't think its too much to ask for your contractor to participate in the cost of the repair. Good luck with this and the rest of the build.

I agree with what your saying. Everyone think it's automatically just tear it out and redo.

I'm hoping for the same. The one local company is saying he think he can fix it very reasonably and yes I agree the contractor should pay for a portion. I know most would accept it and move on. Honestly, I'm not super concerned about the areas close to the wall for the exact reasons you've mentioned. The bays are what I'm going to see the most of and I'd be happy if we just redid the bays and around the drain areas. And really one of the worst is those pits in the floor. Idk what caused those, but they're ugly and right in the middle of the bay. The one crack I have I think is an easy fix with epoxy and they finish right over it all.

This isn't my fortè, so I'm just saying what I think would be a best course of action.

 

[thejudges69]

I'd also add, I don't think majority of guys realize the magnitude of "tear it out and redo." This isn't a walk way for your front porch. To tear out and redo this would be somewhere in the 40-60k dollar range, cause there is radiant heating under the floor that will all be junk. The concrete alone was north of 20k dollars, insulation, heat tubes, tear out. And so on. Is that my responsibility to fix? Absolutely not, but I don't see this slab as junk. It's fixable in the manner it's in without a full tear out and I'm not going to expect my builder to lose all profits when the jobs fixable with ease. Yes that's why they pay insurance, but I think most don't think about things like that. If it's not necessary, why do it. I don't solely blame my contractor. The temperature was hot and only a small portion of this slab was shaded so it dried fast.

 

[thejudges69]

So I have everything set. Friday they're coming to do 2 grinds. 40 and 80 grits and then we'll put a densifier on top of that. Less then a dollar a square foot to clean it up. Will it be perfect? No! But it will be much better.

 

[05snopro440]

I'd also add, I don't think majority of guys realize the magnitude of "tear it out and redo." This isn't a walk way for your front porch. To tear out and redo this would be somewhere in the 40-60k dollar range, cause there is radiant heating under the floor that will all be junk. The concrete alone was north of 20k dollars, insulation, heat tubes, tear out. And so on. Is that my responsibility to fix? Absolutely not, but I don't see this slab as junk. It's fixable in the manner it's in without a full tear out and I'm not going to expect my builder to lose all profits when the jobs fixable with ease. Yes that's why they pay insurance, but I think most don't think about things like that. If it's not necessary, why do it. I don't solely blame my contractor. The temperature was hot and only a small portion of this slab was shaded so it dried fast.

You seem to not like the obvious answers, but this seems like a conversation you should be having with your contractor all along. You're not happy with what you've paid for, and unless you made a big mistake in not specifying the finish on the slab, having the discussion with the contractor that it's not what you wanted and how it can be remedied should be the first action and pretty simple. Whatever the big rush is that you don't want to share, you're having work done and if the contractor knew what you wanted and said they could achieve it, then talk to them.

I had a big amount of ground work done on my acreage this summer, and we had the contractor adjust a few things we weren't happy with as the work progressed. On the finishing, he even did extra work himself because he wasn't happy with the finished job his guys achieved.

Great for you if you're happy to get the grinding set up yourself, but I'd still be talking to the guy that did the job in the first place.

 

[thejudges69]

You seem to not like the obvious answers, but this seems like a conversation you should be having with your contractor all along. You're not happy with what you've paid for, and unless you made a big mistake in not specifying the finish on the slab, having the discussion with the contractor that it's not what you wanted and how it can be remedied should be the first action and pretty simple. Whatever the big rush is that you don't want to share, you're having work done and if the contractor knew what you wanted and said they could achieve it, then talk to them.

I had a big amount of ground work done on my acreage this summer, and we had the contractor adjust a few things we weren't happy with as the work progressed. On the finishing, he even did extra work himself because he wasn't happy with the finished job his guys achieved.

Great for you if you're happy to get the grinding set up yourself, but I'd still be talking to the guy that did the job in the first place.

No I don't like the mentality of most where they revert to the worst case scenario or tear out and replace. That's like asking a body shop to replace all the panels on your classic car cause you don't like the paint job when a simple sand and refinish will give you the exact results your wanting.

Yes I have spoke with my contractor. His communication *****, I won't deny that, so in the meantime I asked on here for feedback since I know there are concrete guys on here. My contractor when we did talk wasn't aware of a way to fix it but we worked it out

As for my timeframe restraints. This is garage journal, not the view, my business is my business and if it bothers anyone that I don't share my business, well sorry, but that's how it is, I share what needs to be shared and that's typically enough. I have 14 days to be complete with this build and it looks like I'm just going to make it with the exception of the garage doors. And lastly, even if I did share what my time schedule was for, exactly how would that benefit this thread? I'm not wanting to tear out and start over, so what would.it do for anyone other then put my personal information online.

 

[05snopro440]

No I don't like the mentality of most where they revert to the worst case scenario or tear out and replace. That's like asking a body shop to replace all the panels on your classic car cause you don't like the paint job when a simple sand and refinish will give you the exact results your wanting.

Yes I have spoke with my contractor. His communication *****, I won't deny that, so in the meantime I asked on here for feedback since I know there are concrete guys on here. My contractor when we did talk wasn't aware of a way to fix it but we worked it out

As for my timeframe restraints. This is garage journal, not the view, my business is my business and if it bothers anyone that I don't share my business, well sorry, but that's how it is, I share what needs to be shared and that's typically enough. I have 14 days to be complete with this build and it looks like I'm just going to make it with the exception of the garage doors. And lastly, even if I did share what my time schedule was for, exactly how would that benefit this thread? I'm not wanting to tear out and start over, so what would.it do for anyone other then put my personal information online.

I never said you should share what your reasons are. You clearly misread my tone by a lot. I simply referenced that none of us can understand your motivation for getting it done so quickly, and your best bet is to talk to the contractor if there's a big time push that he should be aware of.

I'm surprised the contractor wasn't aware of a way to fix it.

 

[Armorpoxy]

Keep us posted on the final result. Grinding will definitely make it better, but it's almost impossible to 'grind flat' without using laser heigh measuring equipment since the grinders will follow the surface of the floor to a great extent.

 

[thejudges69]

Keep us posted on the final result. Grinding will definitely make it better, but it's almost impossible to 'grind flat' without using laser heigh measuring equipment since the grinders will follow the surface of the floor to a great extent.

Its done. Had it ground yesterday to 80 grit. The finish is amazing now, I'm very pleased. Cost me .75 a square foot. Wife and I put a densifier on it last night. It's not perfect, but 200% better

 

[ConCretin]

I's sure I speak for everyone here when I say we'd love to see pics. Some details on the grinding operation would be awesome as well. Glad you found an acceptable solution.

 

[thejudges69]

All I got at the current.

 

[Scooter Scott]

That finished product looks really good.