For a standard 12x12 room (144 square feet), plan on 3 to 5 hours of actual sanding time if you're using a drum sander with the standard three-pass approach (coarse, medium, fine grit). Add another 1 to 2 hours for edging along the baseboards with a handheld edger, since a drum sander can't reach corners or tight spaces. Between passes you'll also spend time vacuuming and wiping down the floor with a tack cloth to catch dust before switching grits, which adds roughly 30 to 45 minutes total.

If you're using an orbital floor sander instead of a drum sander, expect the same 12x12 room to take closer to 5 to 7 hours. Orbital sanders are less aggressive by design, which makes them safer for beginners but slower at removing old finish and leveling the wood.

Scale that up and a 1,000 square foot home (roughly 6 to 7 rooms) typically takes 2 to 3 full days of sanding work alone, not counting drying time for stain and finish. Contractors working efficiently with commercial-grade equipment can sometimes compress this into a single long day, but most DIYers should plan for two full days minimum to avoid rushing the fine-grit pass, which is the step that determines how smooth your final finish looks.

Sanding hardwood floors yourself is a manageable weekend project, but drum sanders have a real learning curve. A drum sander that stays in one spot for even a few extra seconds can gouge the wood, so operators need to keep the machine moving in smooth, even passes with the grain. This is the single biggest concern DIYers bring up: the fear of leaving dips or dig marks that are difficult to sand out afterward.

If this is your first time refinishing a floor, practicing on a closet floor or a section that will be covered by furniture is a smart way to get a feel for the machine's pull before moving to the main living space. An orbital floor sander is generally considered more forgiving for first-timers since it moves in a random pattern rather than a straight aggressive line, reducing the risk of gouges even if your technique isn't perfect yet.

Edging along the walls is often the trickier part of the job, since a handheld edger works differently from a drum sander and can leave visible circular scratch marks if you don't blend the transition carefully with a finer grit.

Skipping grits is the most frequent mistake. Jumping from a coarse 36-grit straight to a fine 100-grit skips the medium step that removes the coarse scratch pattern, leaving marks visible under the finish. Work through coarse, medium, then fine in sequence.

Sanding against the grain, or at an angle to it, creates cross-scratches that show up clearly once stain is applied. Always run the drum sander parallel to the floorboards.

Not vacuuming thoroughly between passes is another common issue. Leftover dust and grit from the previous pass gets dragged around by the next grit, creating fine scratches that are hard to spot until the stain goes on and highlights every imperfection.

Uneven edging is a close second. If the edger pass doesn't match the sheen and grit level of the main floor area, you'll see a visible ring around the perimeter of the room once the finish is applied. Blend the edges carefully with the same final grit used on the main floor.

Rushing dry time between coats of polyurethane is the mistake that shows up after the project looks finished. Walking on a floor before it's fully cured, or putting rugs down too early, can leave permanent marks or cause the finish to stay tacky.

Refinishing existing hardwood is almost always cheaper than replacing it. A DIY sand-and-refinish project, including drum sander rental, an edger rental, sandpaper, stain, and finish, typically runs $1.50 to $3.00 per square foot in materials and equipment rental. Replacing hardwood flooring outright, including material and installation, generally runs $8 to $12 per square foot or more depending on the wood species.

Refinishing only makes sense if the existing floor has enough wood left to sand. Solid hardwood can typically be refinished 4 to 6 times over its lifetime since each sanding removes a thin layer of wood. Engineered hardwood has a much thinner wear layer and may only tolerate one or two light sandings before you hit the plywood base, at which point replacement becomes the only option.