Measure the square footage of the floor in the room you wish to build the dance floor in. Purchase enough sections of medium-density fiberboard to lay out in the room. A single section of fiberboard usually measures eight feet by four feet. Purchase at least one more section than you actually need.
Cut and trim the sections of fiberboard so they will properly fit your room. Take the extra board and cut it along the long side into strips two inches wide.
Lay the fiberboard strips down in the room. Place the strips along the edges of the floor where they meet the walls. The remaining strips will go on the areas of the floor where your fiberboard sections will connect to one another. Lay these strips dow none section at a time and place the section on top of the strips.
Screw each section in place once it is on the floor. To drill the holes, use a special bit that drills a hole for the screw with a larger hole above it for a screw cap; a hardware store specialist can help you find this bit. Drill holes in each corner of the section and more holes a foot apart. Use inch-long flattop screws to fasten the fiberboard section into the strips.
Repeat the above steps for each section of fiberboard until the entire floor is laid out. Cap all the screws once the floor is assembled.
Line at least one wall with full-size wall-mountable mirrors. Check the hardware store for the size and number of precut mirrors you need. The mirrors should come with the proper instructions for mounting.