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.
Best Answer: Concrete's strength is normally expected to reach its design strength in 28 days if it has been cured properly. Curing properly involves keeping the concrete moistened with water for the duration of the curing period or by sealing the surface with a spray-on concrete cure and seal product.he full design loadings on the slab should be avoided for 28 days. The previous durations apply to normal and concrete placements as large as say 3 or 4' thick or more, mass concrete placements continue to cure for an extended period due to the heat of hydration and moisture content issues.