We laid a slab for a huae today. The pumper layed it so wet that it is sagging in some spots. At about noon they wanted

Nicholas S
by Nicholas S
rent a buffing machine. As they were floating it they were making it worst. I know of a machine with grinding stones that would make it somewwht flat. I left when they where renting the float machine because I thought It would just drop through the slab. This is a project for the homeless I thoght it would it would be better to float let it dry gring and float. By the way 1500 sq no mesh just rebar on the corners. Four feet above grade. #6 mud all at once??
  7 answers
  • Nicholas S Nicholas S on Feb 15, 2012
    When I left the water was stil floating
  • Nicholas S Nicholas S on Feb 15, 2012
    KMS HELP
  • Not a good sign. To much water floats the cement to the top and sinks the gravel. You end up with a cement slab that will be soft and dusty. The more you work it when its wet the more you will bring the water to the surface along with the cement. Leaving behind the stones. Not much you can do. Expect to see spider cracking on the surface as it dries out.
  • Sounds like a bad poor....the homeless may be homeless again
  • Sounds like they wanted to rent a power trowel to smooth and flatten the floor. Unfortunately, it also sounds (from your description) that they were rookies who were not sure what to do when problems develop. I would have called the concrete company listed on the pump truck and got some answers from them. Were these guys insured and licensed? I mean both parties, the contractor and the concrete company... What is your recourse if the slab has been installed improperly? Do you have a contract? You may need to have the slab removed and replaced depending on how poorly it was lain. Get some answers. You may need to bring the concrete supplier out and get their opinion. Also, ask them as to who they trust for these installations and get their opinions. Sounds like this can be a big mess in more ways than one.
  • KMS Woodworks KMS Woodworks on Feb 16, 2012
    Sounds like a runny mix...which as woodbridge also mentioned above will yield a weaker and not so great looking pour. when concrete is troweled the "milk" rises to the top this should only be a very thin layer. No mesh also has me worried. What is the name of the building inspector who signed off on the prep before the concrete was poured? There should be section for that in permit.. Slab thickness, rebar and reinforcing net, proper tamped underlayment gravel, etc.
  • I would reject the work outright as improperly completed. Poorly installed concrete is bad news all over the place. ANYTHING you do on top of it for the rest of time is going to be doomed from the start. If concrete is not mixed correctly, it will not be as strong as it should be. You paid for properly laid concrete. If you didn't get it, they still owe you a properly laid slab. If the concrete arrived in wrong proportions, that is their fight with the supplier, not your problem.