Help, Dreaded cracks how bad will they get, what to do?
Help, Dreaded cracks how bad will they get, what to do?
(OP)
I have just spent my life savings redoing the pool deck and patio with stamped concrete. But now after a week and one day it is cracking (not allong the control joints.) Today I have read lots on concrete and the threads here.
The cracks are not very wide at the moment but do traverse the thickness of the slab (can be seen at the edges) and run in random across the slabs. There are currently about 5 or 6 spaced over the work area.
The concrete was layed on a compacted base rock, with a rebar grid, I am concerned that the grid was not pulled up into the slab. I am also concerned about the control joints, maybe these are not cut deap enough and that the concrete was to wet or a poor mix.
What can I do? As this is over a week from the pour I have paid the contractor, what options are open to me? Will the cracks get worse?
I will try and post some photo's if this will help.
Thanks.
The cracks are not very wide at the moment but do traverse the thickness of the slab (can be seen at the edges) and run in random across the slabs. There are currently about 5 or 6 spaced over the work area.
The concrete was layed on a compacted base rock, with a rebar grid, I am concerned that the grid was not pulled up into the slab. I am also concerned about the control joints, maybe these are not cut deap enough and that the concrete was to wet or a poor mix.
What can I do? As this is over a week from the pour I have paid the contractor, what options are open to me? Will the cracks get worse?
I will try and post some photo's if this will help.
Thanks.





RE: Help, Dreaded cracks how bad will they get, what to do?
Some questions for you.
You mention a stone subbase, but was a vapor barrier installed between the stone and slab? That would be more important in my mind than whether grid, which is not universally required in all cases, was used.
Were the joints cut the same day the slab was placed? Timing is critical in that department.
One recommendation I would make is to try and obtain the concrete tickets for your pour. They would provide some information that could be useful to start out.
Next, see if you can get a friend of yours who is a civil or structural engineer to take a look at the deck as a favor. Such a person could definitely provide you with a recommendation.
If nothing else, observe the cracks on a day to day basis and try to determine whether they are getting wider, and if not, sealing may be your best course of action.
If all else fails, one course of action could be to hire a local testing company to core the slab in 2-3 locations. A visual observation of the cores could provide insight as to the condition of the mix, for instance if the aggregate had segregated or large voids were present. The compressive strength of the mix could be tested as well.
You could also determine whether a vapor barrier was installed, and the stone and soil subgrade could be tested at the same time.
If you mean to bring suit against the contractor, I believe the last option would probably be necessary.
RE: Help, Dreaded cracks how bad will they get, what to do?
The base was a layer of class 2 baserock compacted with a vibration compactor, there was no vapor barrier put down but the contractor soaked the area with water the day before the pour.
The joints were placed in the slab with a joint tool as the surface was leveled but before the stampwork was done with a joint tool in the damnp concrete. (Could the stamp process have filled in the joints? They dont seem to be that deep.)
Until yesterday (day 9 after pour) there were no visible cracks but now there are several.
The mix did seem very wet to me, the crew seemed to simply push the mix around using their boots. (this is also why I am concerned that the rebar would have been pushed right to the bottom with all these people walking over it.)
Finally, how do I find a local testing lab, I have tried yellow pages and web but I am not sure what to look for, I am in the San Jose area.
Thanks again.
Dave.
RE: Help, Dreaded cracks how bad will they get, what to do?
RE: Help, Dreaded cracks how bad will they get, what to do?
As suggested in another thread I took a close look at the control joints. All are <1/2" deep some only just over 1/4", I also noticed that one of the cracks formed above a pool pluming pipe where no control joint was placed above it.
I am starting to get a sinking feeling about all of this. I now realy wish I had not paid up the last of the 11K so quickly.
Dave.
RE: Help, Dreaded cracks how bad will they get, what to do?
Hiring a lawyer could well cost you far more than repairing the slab.
RE: Help, Dreaded cracks how bad will they get, what to do?
RE: Help, Dreaded cracks how bad will they get, what to do?
However, you mention two things that stand out to me: "the mix did seem very wet to me"; and "the crew seemed to simply push the mix around using their boots". The Contractor's practice of pushing the fresh concrete around with their boots seems inconsistent with good practice. Did they vibrate, float and trowel the concrete?
It seems to me that the most likely explanation for the cracks is subsidence cracking, which is caused by high water content ("the mix did seem very wet to me"), too rapid placement and insufficient vibration ("the crew seemed to simply push the mix around using their boots").
If you think you're headed for the courts, get and a Professional Engineer involved ASAP and take plenty of photos including close-ups of the cracks (make sure you include a ruler or tape in the shot to establish the scale in the printed photos).
RE: Help, Dreaded cracks how bad will they get, what to do?
All concrete cracks to some extent - but with the rebar or mesh stomped on - its probably on the ground/concrete interface and isn't helping a bit.