In older homes it is good practice to apply a concrete sealer to block moisture or install a vapor barrier on the concrete floor prior to installing the InSoFast panels.
If you have new construction with a vapor barrier already installed underneath the concrete slab, it is not necessary to put another vapor barrier on top of the concrete floor.
Using InSoFast on Both Walls and Floors
Install the InSoFast panels on the wall first. This minimizes the chance of water getting on top of the subflooring in the event the wall leaks.
Measure the floor-to-ceiling height to ensure you will have adequate clearance between the ceiling and the surface of the finished floor to comply with building codes. InSoFast panels alone will raise the floor by 2- to 2½-inches. Subflooring (a minimum of ½-inch is required on top of the InSoFast panels) and your choice of floor covering will reduce the clearance further, so plan accordingly for the best results.