[stevehull]

Drake,

Is the surface of your thin slab going to be the final floor? If so, do not use fibers as they stick up and are very difficult to get a "clean" finish on the concrete surface.

An alternative is to put the fibers in the concrete, roughly level it out and within 12 hours pour on a 1/4 inch (4 mm) concrete floor leveler. The initially almost liquid floor leveler pours virtually flat and bonds exceptionally well to concrete if done with a few hours of the initial concrete pour.

But practice is key with floor leveler as it sets up VERY quickly. It can go from very liquid to a putty like substance in just 10 minutes. I love it as you can put on a perfectly smooth finish without all the finishing that a concrete floor surface requires. In fact, a "rough" surface is great as the floor leveler really grips into that rough concrete surface.

And the floor leveler can have a smooth almost glass like surface with no work. In fact, if you work floor leveler, it sets and then you don't have that smooth surface.

As you can tell, I love floor leveler and have used it in a garage, in a basement and on an outside patio. The cost savings was high as you don't have to pay for the expensive labor to smooth out the surface.

Steve