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.
When it comes to protecting a concrete foundation you only have one chance to build a concrete foundation right the first time. Typical Spray-on-coatings may take from 12-72 hours or longer to fully cure. However, a concrete foundation may take up to 60 days before it reaches maximum strength. When a coating is applied to a concrete foundation it may seal in moisture, which could result in the concrete foundation taking longer than necessary to cure.