Are these cracks excessive?

[theKman]

Later today, I'll be applying Legacy's Silax-Seal to this floor, and in a few days, RaceDeck Free-Flow. This is in a new 24x30 attached garage, and the slab was poured 1/8/16. Before I cover it with RaceDeck, should I be concerned about the level of cracking so soon after pouring? The cracks are rather narrow at less than 1/8", and appear to be the same height on both sides. And before anyone says it, I'm aware of the adage that "all concrete cracks", it's just that to me, this seems excessive. If it helps, the high temp the day it was poured was approx 43 degrees, the low was below freezing, and the highs and lows remained that way for a few days. Tarps were placed over the slab for a while after, I forget now how long. I also don't recall if a curing compound was used, but I know there had been talk of it as a possibility. This is a link to a video of the concrete being poured off the truck:

https://www.sugarsync.com/pf/D307298_79_7510762668

Anyway, I just want to be confident that I'm not looking at structural problems in the future. The contractor is still due his final payment.
Thanks.

 

[p_mori7]

That's a lot of cracking for such a recent slab. Is the slab reinforced with mesh or rebar ? This will help mitigate any potential vertical shifting.

FWIW, my monolithic slab is 5 years old now, mesh and rebar in it, and I have only 2 hairline cracks in it. No separation horizontally or vertically.

 

[theKman]

Is the slab reinforced with mesh or rebar ?

Neither mesh nor rebar was used. At the time, I had planned to put in an Atlas 2-post baseplate lift (now I'm just going with their scissor lift), so I told my GC that the concrete needed to meet the criteria listed in the installation manual, which is:

1. Concrete must have a thickness of 4 inches minimum and without reinforcing
steel bars, and must be completely cured before the lift installation.
2. Concrete must be in good condition and must have a test strength 3,000 psi
(210kg/cm²) minimum.

Although I think at the time, 3,500psi was spec'd.

 

[brownbagg]

why you have pole on a garage that small, you have a loaded second floor?

 

[theKman]

why you have pole on a garage that small, you have a loaded second floor?

Yes, actually there's two poles. There is a full second floor over the garage accessible from the master bedroom. There were footings poured deeper where the poles sit, it's visible in the video.

 

[Chris705]

The only thing to be concerned with now that it has cracked, is will it possibly settle unevenly. If the sub grade was well compacted you really have nothing to be concerned about. It's been talked about at great length on this forum that concrete shrinks as it cures. Many reasons why it does and doesn't crack in a given slab. Since your slab will be under racedeck cracks won't be seen...sealing the slab will ensure keeping concrete dusting to a minimum and help with keeping dirt/spill stains off it.
Crack width is mostly dependent on the amount of water in the mix design, often wide cracks are the result of "self leveling concrete" Contactor asking truck driver to add more water to "lossen" it up to ease placement.

 

[LegacyIndustrial]

The modular tile should hide the cracks nicely.


Sent from my iPhone using Tapatalk

 

[Dr Stan]

This is in a new 24x30 attached garage, and the slab was poured 1/8/16. Before I cover it with RaceDeck, should I be concerned about the level of cracking so soon after pouring? The cracks are rather narrow at less than 1/8", and appear to be the same height on both sides.

Anyway, I just want to be confident that I'm not looking at structural problems in the future. The contractor is still due his final payment.
Thanks.

I agree that it is excessive cracking so soon, less than a year. My contractor poured a 24 X 48 monolithic slab & foundation and used rebar. I also specified the concrete to have fiberglass in the mix.

However, the one feature he made was to cut the slab part way through to help reduce the effects of stress.

I advise you to have the contractor and someone from the local zoning board look at your floor. I'd also consider having a competitor look at the floor.

 

[cajunfirehawk]

The one guarantee my cement man always told me, bet on this: concrete WILL crack!

 

[matt_i]

No steel reinforcement and no saw cuts to control the cracks pretty much guarantee that its going to crack randomly as the concrete cures and shrinks.

I wouldn't worry too much about it as long as the subgrade is well-compacted.

 

[James-W]

I am certainly no expert on concrete, but my thinking is that if you fill the cracks with a patching substance that can expand and contract a bit, then put the Racedeck flooring down, you most likely will not have any issues. The cracks you won't see, I doubt they will get any bigger anyway, and the Racedeck tiles will look really nice on the floor. That's my personal opinion on the subject.

 

[theKman]

Thanks for the input everyone. I'll discuss it further with my GC.

Stripper pole?

 

[PWC Repair]

I always heard you get 3 guarantees with concrete:
1- Guaranteed to get hard
2- Guaranteed to crack
3- Guaranteed nobody will steal it

 

[SunsetsAndFriends]

Concrete can be placed to minimize or even eliminate cracking. It can be done. I poured my own patio. No cracking. Properly prepared crushed stone base and concrete with lower water content. After 6 years not one crack.

 

[jimchevy]

Concrete can be placed to minimize or even eliminate cracking. It can be done. I poured my own patio. No cracking. Properly prepared crushed stone base and concrete with lower water content. After 6 years not one crack.

I agree! My 24x32 slab was poured over two years ago and not a single crack! They put score lines in the slab and it's perfect. I etched and epoxy coated mine.

 

[SunsetsAndFriends]

I agree! My 24x32 slab was poured over two years ago and not a single crack! They put score lines in the slab and it's perfect. I etched and epoxy coated mine.

Nice floor! My biggest mistake was hiring a "contractor" to pour my workshop floor in my basement. I ended up doing a lot of chasing of cracks and grinding to get it looking descent. The worst money I ever spent. I'll never hire for concrete work again. And the only reason that I did was lack of help.

 

[RaceDeck1]

A little sealer and snap in RaceDeck garage flooring on top will do the trick...

 

[ForceFed70]

I agree with others. I would be disappointed with that much cracking. But it's not what I'd call excessive or something that will lead to a problem.

To me this cracking looks to be related to curing/shrinkage rather than settling which is a good thing obviously. Too bad no steel was used.

Put the tile down and forget about it

And yes - for the record my 32x40 with control joints 10' OC doesn't have a single visible crack. Poured 4 years ago now - likely cracked in some of the control joints tho.

 

[jimchevy]

My garage floor that is attached to my house has those but were like that when I bought the house. Most likely from improper compaction. In that garage I plan to use the long plastic mats with the raised coins in each bay and epoxy the perimeter of the floor and between the mats.

 

[audioworks04]

Concrete typically will see all of its scrinkage cracks with-in 96hrs of placement. Anything that happens after that is due to setting of the building or excessive loading. The American Concrete Institute recommends control joints to be installed (jointed, cut or formed) on a 10ft spacing for a 4in thick slab. If placed correctly they will "activate" and cause the slab to crack in this control joints.
The type or amount of reinforcement has nothing to do with a correctly installed slab cracking. Rebar or mesh is not for shrinkage or plastic cracking or structural support.
But answer your question, no I would not worry about them as they appear to be shrinkage cracks not settlement cracks. Now if they are opened up or have a noticeable elevation differance on the surface then they are most likely structural crack.

 

[theKman]

How about now? Do the cracks seem a bit better now? Less noticeable?



Edit: Upload better pic.

 

[piker28]

Pole in the middle....Chair on the outside of the white line....

Do you put a car in there or is this for a different type of setting

 

[jywilli69]

How about now? Do the cracks seem a bit better now? Less noticeable?



Edit: Upload better pic.

Can't see any cracks.

 

[Superbec]

Pole in the middle....Chair on the outside of the white line....

Do you put a car in there or is this for a different type of setting

pole looks a bit thick ...

 

[Sasquatch912]

Stripper pole.

Chair there for lap dance.

Needs disco ball now.