Q.: What should you do if rain hits after the slab has been placed?
A.: The requirement is to be prepared. You cannot do much of anything if you are not prepared ahead of time. You should have on hand some portable shelters or at least some polyethylene and lumber from which a shelter can be quickly improvised. The slab should be immediately covered in such a way as to keep the rain away from the surface while allowing the rain to drain away from the slab. At any time that the slab is ready to be bull-floated, floated or troweled, the portable shelter should be set over a small portion of the slab and then the slab under the shelter should be uncovered long enough to work on it. The portable shelter is then moved from place to place while the particular finishing operation is carried out. The same procedure is repeated with subsequent finishing operations as long as the rain lasts.