Clarify time between coats on an existing floor that is extremely porous?
Although only one (1) coat of Trojan is generally needed, the first coat should be to saturate the substrate. That is to keep applying Trojan until the floor will no longer absorb any more. Then the floor should be back-rolled to mop up any excess. If a second coat is to be applied then it should be before the first coat has dried. On some extremely porous concrete, the first coat may be allowed to dry completely and then a second coat applied. Make sure that the excess is back-rolled to remove from the surface (you will know the concrete is dry because when it is wet it turns a darker color and lightens as it dries). The length of dry time varies due to how much the floor absorbed, the air temperature, the air movement, and whether there is sunlight on the floor. Some floors dry in a day or two and some may take a week or more to dry.
