How to Sand Hardwood Floors: A Step-by-Step Guide
Sanding is the step that decides how your finished floor will look. Every scratch left behind will show through the finish. This guide covers the process in the order professionals do it.
Before You Start
First confirm that your floor can be sanded. Solid hardwood can usually be sanded several times. Engineered flooring depends on the thickness of its top layer, and a thin layer can be sanded through. If you are not sure, check with a professional before renting anything.
You will need:
- A drum sander, an edger, and a buffer or orbital sander
- Sandpaper in several grits, from coarse to fine
- A shop vacuum
- A respirator, hearing protection, and safety glasses
- A nail set and hammer, wood filler, and a scraper
Step 1: Prepare the Room
- Remove all furniture, rugs, and curtains
- Remove shoe molding or baseboards if you can, so the edger can reach the floor
- Set any nail heads below the surface with a nail set, because they will tear the sandpaper
- Fix loose boards and fill large gaps
- Cover doorways and vents with plastic to limit dust
- Vacuum the floor thoroughly
Step 2: Start With the Drum Sander
Load the coarsest paper suited to the floor. A floor with old, heavy finish needs a coarser grit than a floor that only needs a light refresh. Test in a closet or a hidden corner first.
Lower the drum only once the machine is moving, and raise it before you stop. Sand with the grain, walking at a steady pace. Never let the machine sit in one spot. Overlap each pass slightly.
Step 3: Work Through the Grits
Each grit removes the scratches from the one before it. Move from coarse to medium to fine, and do not skip several grit levels at once. Skipping leaves deep scratches that the finer paper cannot remove. Vacuum between grits, because loose grit on the floor will scratch the surface.
Step 4: Edge the Room
The drum sander cannot reach the edges. Use the edger along the walls and in closets with the same sequence of grits. Blend the edger marks into the main floor so there is no visible border.
Step 5: Buff and Blend
A buffer or orbital sander with a fine screen or paper smooths the surface and blends the transitions between the drum and edger work. This is also the point to scrape any corners the machines missed.
Step 6: Clean Everything
Dust left on the floor ruins a finish. Vacuum the floor, the walls, the windowsills, and the tops of doors. Wipe the floor with a tack cloth or a slightly damp cloth, and let it dry before you apply stain or finish.
Common Mistakes to Avoid
- Leaving the drum down while the machine is stopped, which digs a dent in the floor
- Sanding across the grain
- Skipping grits to save time
- Skipping the vacuuming between grits
- Rushing the edges
Our guide on common DIY refinishing mistakes covers these in more detail.
Rent the Equipment or Hire the Crew
If you decide to do the sanding yourself, Denton's rents professional equipment with video training. See the floor sander rental package, and read how to rent a floor sander before you book. If you would rather have it done for you, we offer hardwood floor refinishing in Knoxville with a dustless sanding system.