Howe much postage to send a postcard from US to Canada? As of September 2014, it costs $1.15 to ship a post card  internationally. If it exceeds 4 3/4 inches high or 9 1/4 inches  long, you will be charged the First Class Mail In â¦ ternational price. + 3 others found this useful.
Concrete is never truly done curing, but the minimum wait time should be 28 days. A slab typically cures at least 80% during that time. I suspect the manufacturer is asking you to proceed cautiously to avoid a lawsuit. If you (or your client) can wait that long, then wait the 120 (or more) days. But I wouldn't put any flooring on it inside a month.
Confidence votes 142. Typical concrete takes 28 days (4 weeks) to cure. Prior to the 28 days concrete still has moisture in it that weakens the strength of the concrete. If you seal it prior to 28 days there is a chance you will be sealing in some of that moisture and hence weakening the integrity of the concrete.onfidence votes 142. Typical concrete takes 28 days (4 weeks) to cure. Prior to the 28 days concrete still has moisture in it that weakens the strength of the concrete. If you seal it prior to 28 days there is a chance you will be sealing in some of that moisture and hence weakening the integrity of the concrete.