The concrete foundation must be a smooth, flat surface. Check for any gouges, nail heads or loose particles. Cut any nails or screws flush to the surface and fill in any holes left from pulling up carpet nails. The foundation must be level, but if it isn't, use a self-leveling concrete rated to withstand the weight and pressure of dancers' jumps. Freshly poured concrete must thoroughly cure for 30 to 45 days. Afterward, lay a polyethylene moisture barrier over the entire concrete foundation to prevent seasonal moisture from rotting the sub-floor. Overlap the edges, and join using vinyl tape.
Here, the methods of installing the floor diverge. A pre-assembled kit normally provides all layers of the sub-floor, including a wood or medium-density fiberboard (MDF) rise that raises the dance floor off the hard concrete, closed-cell foam for cushion and spring, and a top layer of plywood. These layers arrive pre-assembled as manageable "tiles" ranging from 36 to 42 inches. They feature a tongue-and-groove or wave-lock system that "snap into place," preventing the tiles from shifting over time. These tiles can be cut to size, using a saw, to accommodate any-sized room or dance floor design configuration.
Assembling the sub-floor yourself requires purchasing all of the individual pieces: studs for the joists to raise the floor, wood or MDF, closed-cell foam and plywood, then doing all the measurements and cuts for each layer. Using joists to raise the floor and closed-cell foam for cushion provide "spring," absorbing energy and giving some back to the dancers. This is called a "sprung floor." While doing it yourself is labor-intensive, it can be less expensive than a pre-assembled floor and can go quickly if you have friends to help.
Cut one plywood board into enough four-inch strips--or buy one- by four-inch skirting--for the skirt girder. Bolt the skirt girder to any wall that meets the perimeter of the dance floor. Lay the two- by four-inch studs--joists--on their short side and place 16 to 20 inches apart, using deck screws to secure the joist ends into the skirt girder. The joists are the riser that elevates the dance floor off the concrete which helps prevent joint damage to the dancers.
Lay a good quality plywood or MDF across the joists and screw into place, cutting the last boards to shape. If the dance floor area does not meet a wall, use a saw to cut the plywood flush to the outer joists. Roll out the closed-cell foam and tack into place with nails. Another layer of plywood is then placed on top, secured with deck screws, and any overhang trimmed with a saw. The subfloor must be free of loose particles and all screws or nails flush to the plywood. Sanding the floor may be required to ensure it is level and smooth, followed by a thorough sweeping.
A heavy-duty vinyl, "marley" dance floor must be ordered from a dance floor company and arrives rolled up. Roll out the flooring and cut to the lengths required to cover the floor. The edges must meet precisely, but cannot overlap. Double-stick tape is placed on the underside to attach the dance vinyl to the subfloor. This allows the dance floor to be moved if the company travels. For a permanent dance floor, the edges of the vinyl dance floor should be heat welded by a professional dance floor installer. Once set, the floor is ready for dancing.