Cracks in the floor!!!!

[vtxcandyred]

Cracks in the floor. It was poured and the block was set by a contractor. A couple of them were fairly inconsequential and I filled them with floor paint I have. The new one is as wide as my pinky and runs from the center to the corner. It’s a twenty four by twenty four garage. I wonder what I can do to stop this?????? Thanks.

 

[powpow]

Was the floor cut for the control joints or does it have tooled joints?

 

[CARS]

That *****. A friend of mine says there is two types of concrete.
Concrete that has cracked, and concrete that will crack.

Who did the prep work?? Excavation, fill, packing, etc.

 

[ConCretin]

A crack as "wide as your pinky" is probably not a shrinkage crack. Pictures would help but I would suspect that your sub grade is inadequate and caused your slab to crack.

Unfortunately there isn't much you can do at this point.

 

[mebedave]

Cracks in the floor. It was poured and the block was set by a contractor. A couple of them were fairly inconsequential and I filled them with floor paint I have. The new one is as wide as my pinky and runs from the center to the corner. It’s a twenty four by twenty four garage. I wonder what I can do to stop this?????? Thanks.

Sorry to hear that! Any chance you can get your contractor to come take a look at your problem,how long ago did you pour? This pinky size crack…. Is the crack shifting or just pulling apart, what I mean by that has one side of the crack dropped lower than the other.
What kind of steel did you use? Hope it is not mash, hate that stuff. I only use rebar, the only time I’ll use mash is maybe and I mean maybe on a walk way. I tear a lot of concrete up that has mash in it, 99% of the time (wait... more like 99.9% of the time) the mash is stuck to the bottom side of the slab. Even if the guys pouring pull the mash up into the slab like they should (most don’t) as soon as they step on it, it’s smashed back down to the bottom. Same can happen with rebar, but most guys will space their rebar on a 2x2 grid and they have room to step between the rebar grid without stepping on it, and pushing it back to the bottom. I see a lot of rebar at the bottom of slab too when I tear it up but not near as much as mash, and that’s most likely because they did not even try to pull the rebar up while pouring. Next time you see a crew pouring just stop and watch see if they pull up the steel what ever kind they happen to be using. Lot’s of these guys just don’t care or the boss is not watching.

That being said, there’s only two guarantees it the concrete business
1. It’s going to get hard
2. it’s going to crack

When I poured my shop I used #5 rebar on 18”x16” grid 5 inch thick 4000 psi and I was the guy with the hook pulling the rebar up and yelling at anyone that was stepping on the rebar (did a lot of yelling that day)

 

[Daniel Dudley]

There are cracks that happen because the underlying soil was insufficiently tamped, or improper fill was used.

 

[Falcon67]

Have a foundation company come and assess the slab. It may require mud jacking or driving piers under parts of the slab and/or reworking the footers. Had that in the old shop - it was caused by an inadequate footer and water runoff working on one side of the building. Handled the runoff issue, which stopped crack growth but didn't do anything else.

 

[Jagmandave]

My home is older, but my slab is getting really bad in one place due to a chipmunk burrowing under the slab, then when it rains it washes out the substrate.

I have traps set now and have caught 3 of the little bastiches so far......

 

[mebedave]

Have a foundation company come and assess the slab. It may require mud jacking or driving piers under parts of the slab and/or reworking the footers. Had that in the old shop - it was caused by an inadequate footer and water runoff working on one side of the building. Handled the runoff issue, which stopped crack growth but didn't do anything else.

Hmmm, funny you should say that...This is what I do for a living. http://www.keatingmudjacking.com/steel_piers.html this is my family's bis. Falcon I think you nailed it, but I don't think he wants to here this.

 

[NUTTSGT]

I'm curious to the age of the new floor.

 

[powpow]

So heres the gig,

you will get EXACTLY what you paid for

I do concrete work on the side and I see people trying to get by cheap, here are the rules I abide by

1. 4-8 inches plus of sand on top of 3-4 inches of 3/4 minus with fine on a SOLILD base
2. 1/2 inch rebar in 12"x 12" sections
3. 5 inches of 4000lb mix minimum, for a slab on grade the outside needs to be 12 -18 inch thickened
4 Saw cuts, I typically make them as square as possible, we like to do 8ft x 8ft squares for crack control joints

If the contractor you hired DID not do this, you have issues that cannot be fixed, except by jacking up the building and pouring a new floor

 

[1983Camperspecial]

2 things you can guarantee about concrete...Its gonna get hard and its gonna crack. fill the crack and move on with life.

 

[brownbagg]

concrete does not always crack, a slab done correctly will not crack. The excuse that all concrete crack is just an excuse for poor workman ship and the fact they dont understand concrete.

But once the concrete cracks, there is not much that can be done except seal the crack.

 

[ket-tek]

When you say the size of your pinky, do you mean you can stick your pinky in the crack because it has opened up that far? If so, wow that's a bit extreme. But otherwise you can use IntegraFlex flexible crack filler and then paint over it, this will fill it nicely and allow for some expansion/contraction without exposing the crack again, unless it is seriously pulling apart a gap you can stick your fingers into..

Can you post some pics?

 

[binkcat16]

sounds like your foundation was done poorly not enough clay and wasent packed well enough

 

[Worsedog]

Concrete cracks because of poor base prep or improper curing. The main area of my garage is 30 x 40, one continuous poor with no saw cuts. It is about 20 years old and has no cracks.

The concrete in front of it is another story. It looks like it was poured by a pair of ten year olds and finished with a 2 x 4. It is cracked to **** and it has expansion joints in it.

 

[mebedave]

I think he fell into the crack, his not responding….

 

[NUTTSGT]

I think he fell into the crack, his not responding….

I didn't think the crack was that big but you never know.