Q. When is the proper time to start curing decorative concrete that's textured using mats or skins and colored with a dry-shake hardener and release agent? Some people say curing should begin immediately, but whenever we try to use impermeable coverings, such as plastic or waterproof paper, we get discoloration. And we can't apply a cure-and-seal product until the next day, after we've washed off the release agent.

A. We talked to several decorative-concrete contractors who agreed that plastic or waterproof paper isn't the best curing method. Some manufacturers indicate that the release agent holds in enough surface water to adequately cure the concrete until it can be power washed the following day. Then, after the slab dries, they recommend applying the curing and sealing compound.