For concrete subfloors, thoroughly clean oil stains and loose particles using an industrial vacuum and pressure washer. After drying, apply a primer to enhance adhesion. Fill fine cracks with flexible sealant. New concrete subfloors require at least 28 days of curing. Wooden subfloors demand more attention: check for rot (replace planks with over 30% decay), treat all wood with preservatives (copper-based recommended), and apply waterproof coatings. In damp areas or ground-contact installations, use a moisture barrier with 200mm overlaps at seams, sealed with waterproof tape. For elevated installations, space joists 300-350mm apart, using stainless steel or treated wood joists leveled with a laser. Avoid copper or iron treatments directly contacting bamboo to prevent discoloration. In coastal or high-salt areas, apply anti-salt spray coatings to the subfloor.