Re: Bubba\'s Basic Barn
wire and / or rebar only keep the concrete from separating if it does crack. It doesn't keep it from cracking. Cracking is caused by many things that are difficult to diagnose unless you can physically inspect the concrete job, the underlying substructure and the installation procedures. All these factors are important to understand why the job failed. My un-educated guess since I am not able to see the job is that the material under the floor being very dry, was not compacted enough and it shifted. Also, if they didn't put down a vapor barrier in the floor before the concrete was poured, the dry powdery material under the floor would have pull the moisture out of the concrete rapidly and that would cause the concrete to fail. Concrete gets its strength by slowly drying or curing being the correct term. The correct way would have been to have kept wetting the top of the floor the following day with a garden hose and to have continued to "watered" the floor for at least 30 days. The floor was sealed and it shouldn't have been done until much later. Watering would have given the floor its maximum strength and longest cure time. Even after 30 days, it will continue to "age" and cure and gather strength. This is why you will see them pour the bridge piers for highways many months in advance of when the steel is to arrive. They are allowing the concrete to cure to maximum strength. Also, if the contractor had the concrete truck drive add additional water to the mix after it left the concrete mixing facility where the proper ratio of sand, stone, and cement were place into the vat then that also will effect the strength. It is called changing the "slump". Adding water to the mix makes the concrete flow easier and the guys putting the floor down, like that. It is easier to move around. It also creates more voids in the concrete when the water evaporates from the mix resulting in a weaker concrete floor. A stiffer mix is a denser mix and a stronger floor. Concrete comes in various grades, 2000#, 2500#, 3000#, 3500#, etc mix. The higher the pound number, the more that it cost. If the job is a contract job based on price, then they order the least expensive concrete that will get the job done. Unfortunately, most home owners don't learn all this until after the job is done. Most people only build once and if they have a bad experience the first time, they don't even want to think of doing it a second time. I was fortunate enough to have worked construction at one time and learned a lot of the trades.
