I have laid engineered oak flooring onto 12mm Celotex over a concrete floor. Although the concrete floor was level it wasn't flat I tried to correct this w I've self levelling concrete with some success, however the floor is a bit bouncy, is this the Celotex? Due to door openings I can't go any thicker with the Celotex. The next floor I thought I would use 6mm plywood over the Celotex before laying the oak floor. Will this help? Any other ideas please.
