The subfloor is the foundation of any sports flooring system, influencing stability, shock absorption, and longevity. Common subfloor materials include concrete, plywood, and oriented strand board (OSB), each with pros and cons.

Concrete provides a rigid base but requires a vapor barrier to prevent moisture damage. Plywood offers flexibility and moisture resistance but may warp if not installed correctly. OSB is cost-effective but less durable than plywood. The subfloor must be level (tolerance ±3mm over 2m) to avoid uneven wear on the wooden surface. Proper insulation between the subfloor and ground further enhances energy efficiency and soundproofing in multi-story venues.