how long does tile need set before walking on it
Allow thinset to dry for 24 to 48 hours. Thinset mortar adheres tiles to floors, countertops, backspashes and walls. It shouldn't be walked on or disturbed during the drying process, as doing so could cause a serious misalignment of the tiles you just laid, a problem that would be difficult to fix. This means you need to allow it to dry before grouting.