What are common causes and what can be done to prevent them? 40x50 poured in mid Dec...its been pretty cold here since but this pour is cracking everywhere. Contractor spread and tamped fill prior to pouring...I inquired if DGA was req'd...they said no this fill was packing really tight. I know they didn't put anything down (mesh or underlayment). He looked at it yesterday and said I have water freezing under and there's nothing he could do.
preventing cracking
- Thread starter 64duece
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EOC_Jason
Well-known member
40x50 with no rebar, mesh, or post tension? What's holding it together?
383
Well-known member
Sounds like it's a little late for preventing cracking. That is usually done before the slab is poured. Crack control joints cut in the slab after it's pour don't keep it from cracking, it just cracks where you want it to.
Rebar in the slab doesn't guarantee that it won't crack, but it does help hold the pieces together after it cracks.
Rebar in the slab doesn't guarantee that it won't crack, but it does help hold the pieces together after it cracks.
So how does this guy KNOW that water is freezing under the slab? X-ray vision?
Sounds like he did a piss poor prep job and you should hold accountable for it.
My floor is all cracked up also, it's disappointing but there is not much you can do.
Sounds like he did a piss poor prep job and you should hold accountable for it.
My floor is all cracked up also, it's disappointing but there is not much you can do.
Bruce4310TX
Well-known member
Even with proper compaction concrete will crack......its the rebar that holds it together period. Wire mesh better than nothing, fiber useless and a waste of money best scam out there sounds like you didnt specify what you wanted in writing.
Rookie2
Well-known member
Can you say SHISTER ! You'll either have to live with the constant cracking or dig it out and get an honest concrete contractor.
I'm not trying to prevent what's already down...its down and looks like a rookie job. I'm gonna leave it down for a few months and expect it will get worse. We may re-pour a section at a time and the advice I get here will ensure the next guy is on par because Ill demand better with the knowledge Ive gotten here.
ConCretin
Well-known member
It's entirely possible to prevent cracking in a typical residential garage slab - it's just takes a little more effort. Understandably, most people just cut control joints so they don't have to deal with it.
The trick is to mitigate shrinkage, which is the primary cause of random cracks. To control shrinkage, you must control the water, more specifically the mix water. You want to minimize the amount of water used to batch the concrete and then minimize the loss of mix water after placement through proper curing.
The conventional wisdom that 'there are two kinds of concrete...." is complete ****. If you're willing to put in the effort, there is no reason you can't construct a crack free slab.
Those that suggest that steel reinforcing is a benefit are correct, but rebar or mesh do not prevent cracks. They do serve to hold everything together and preserve the structural integrity of the slab if cracks do occur.
With respect to the contractors comments about water freezing underneath being the cause of the cracking...........well, that's just more ****
The trick is to mitigate shrinkage, which is the primary cause of random cracks. To control shrinkage, you must control the water, more specifically the mix water. You want to minimize the amount of water used to batch the concrete and then minimize the loss of mix water after placement through proper curing.
The conventional wisdom that 'there are two kinds of concrete...." is complete ****. If you're willing to put in the effort, there is no reason you can't construct a crack free slab.
Those that suggest that steel reinforcing is a benefit are correct, but rebar or mesh do not prevent cracks. They do serve to hold everything together and preserve the structural integrity of the slab if cracks do occur.
With respect to the contractors comments about water freezing underneath being the cause of the cracking...........well, that's just more ****
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Oggy
Well-known member
Click the link in his footer, then, tell me if you think LL knows what he's talking about.