What is the cheapest way to refinish hardwood floors?

The cheapest way to refinish hardwood floors is to do a screen and recoat rather than a full sand and refinish, and to do it yourself. A full sanding with drum sander rental costs money and is labor intensive, while screening involves using a floor buffer with a sanding screen to lightly scuff the existing polyurethane finish and then applying a new topcoat of polyurethane, which refreshes shine without removing stain. This costs only about 50 to 100 dollars for buffer rental, screens, and a gallon of polyurethane for an average room. If floors are too damaged for screening, the cheapest full refinish DIY approach is to rent a drum sander and edger from a home improvement store for about 150 dollars per day, buy sandpaper in multiple grits, and use an oil-based polyurethane which is cheaper than water-based and requires fewer coats. Prep work like removing furniture yourself, filling gaps with wood filler, and thorough vacuuming saves labor costs that would be 3 to 5 dollars per square foot if hiring a pro. Using a stain and polyurethane combo product also saves money and time. Always wear protective gear and work in ventilation to avoid extra costs from mistakes.