When I questioned the cracks on my lanai floor they sent out the foreman from T & D and he told me cracks are normal. He also said if I would pull up the carpet I would find more cracks. I asked him if he had ever been to Italy where they have been using cement for over 2K years. Some of these buildings have no cracks even in areas subject to earthquakes. I feel that they pour fast and build quick here, I for one am not convinced that concrete and cement will crack. With no Rebar it will crack.
