Like installing over wood, the first step is cleaning the concrete thoroughly. You can choose a cleaner that is designed specifically for cleaning concrete. Use a power broom or push broom to scrub stains, mold, or other debris from the surface.
Pay attention to drainage. If you see puddling on the concrete, you may need to drill drainage holes to avoid pooling. Fill the gaps with 10 mm shingle.
Use a self-leveling compound to repair small cracks if there are uneven surfaces.
Let the concrete dry completely before installing the foam underlay. Lay out the foam underlay and cut it to fit. The foam comes in rolls and sometimes tends to roll up so weigh it down to keep it in place. Use some masking tape to hold the pieces in order until glued down. Follow the manufacturer’s instructions for using the glue, ensuring all areas are covered thoroughly.
