How to Refinish Hardwood Floors Like a Pro

The price for refinishing hardwood floors ranges from $3 to $8 per square foot, including material and labor. Those with DIY skills can get these costs even lower by refinishing their floors themselves.

refinish hardwood floor

Tools and Materials

You’ll need to gather these tools and materials:

  • Sanding Equipment: Orbital sander, edger, and buffer.
  • Safety Gear: Dust mask, goggles, gloves, respirator mask, etc.
  • Finishing Products: Polyurethane, varnish, hard wax oil, stain, and wax.
  • Cleaning Supplies: Applicators, shop vacuum, tack cloth, plastic sheeting, etc.

Preparing the Room

1. Clear the Room

Remove all furniture, rugs, and other items from the room. 

2. Assess the Condition of the Hardwood Floors

Assess the condition of the hardwood floor and identify damaged or worn boards. Also, check for protruding nails. Hammer down any nails that are sticking out.

3. Protect Surrounding Areas

Prepare the room by covering doorways and vents with plastic sheets or tape. Seal any openings or gaps in the room to prevent dust from entering adjacent spaces.

Sand the Hardwood Floors

Step 1: Choose the Right Sandpaper Grits

Select grits based on floor condition and sanding level. Use this guide for hardwood floors:

  • Coarse grits (below 60): Best for initial sanding since this grit can remove old finishes and scratches and level uneven areas.
  • Medium grits (60-80): Medium grits ensure a smooth surface, remove moderate imperfections, and prepare for the final stages.
  • Fine grits (100-120): Fine grits are suitable for final sanding before applying the finish. They eliminate visible scratches while creating a uniform base.
  • Extra-fine grits (150 and above) (Optional): They achieve extra-smooth finishes and are ideal for sanding between coats.

Step 2: Start with a Rough-Grit Sanding to Remove the Old Finish

Sand using a coarse-grit drum sander (around 36-60 grit) to remove the old finish and level the floor, starting from a corner. Ensure continuous motion of the sander along the wood grain to prevent uneven sanding.

Step 3: Progress to Finer Grits for a Smooth Surface

After initial coarse-grit sanding, redo with finer grits (80, 100, 120) for a smoother surface. Work your way up, using each grit until you reach 120.

Step 4: Final Sanding with a Buffer or Orbital Sander (Optional)

Opt for a buffer or orbital sander with a fine-grit (around 150-180) screen or sandpaper. This final step achieves floor surface smoothing, eliminating scratches and achieving the proper finish foundation.

Step 5: Sand the Edges and Corners with an Edger

Transition to the edger post-drum sander. An edger tackles room edges and corners beyond the drum sander’s reach. Maintain even pressure to avoid gouges. Begin with coarse grit, then move to finer grits.

Additional Sanding Tips for Optimal Results

Sanding along wood grain yields an even, smooth finish. Sanding against grain causes stubborn scratches.

  • Check the floor for unevenness.
  • Fill low spots or gaps with wood putty while following manufacturer instructions.
  • Use a shop vacuum or dust collection system to ensure cleanliness and visibility during sanding.
  • Pause periodically for equipment cooling.

Repairing and Patching Hardwood Flooring

Before you apply a new stain or sealant, you need to repair any damaged floorboards.

1. Inspect for Damaged or Loose Boards

Examine the hardwood floor to identify any areas that need repair. Look for cracks, gaps, dents, scratches, or other damage.

2. Replace or Repair Damaged Sections

Use a circular saw or a chisel to remove the damaged panel. Cut a new board to fit the space, leaving a slight gap for expansion.

Secure the new board using nails or screws, and fill the nail or screw holes with wood filler. Sand the replaced board to match the rest of the floor.

3. Fill Gaps, Cracks, and Nail Holes

Fill small gaps and cracks between floorboards with matching wood filler or putty. Apply using a putty knife, smooth, and allow to dry following manufacturer instructions.

Use wooden shims or splines secured with wood glue for larger gaps or cracks. Trim any excess and sand the area until level with the floor.

Address shallow scratches with a hardwood floor cleaner and a soft cloth, ensuring you rub in the direction of the grain. Use fine-grit sandpaper for sanding down deeper scratches or dents. Avoid aggressive sanding to prevent noticeable floor depressions.

Ensure a Level and Even Surface

Use a floor or handheld orbital sander with coarse grit to remove filler and unevenness. Shift to finer grits for improved smoothness. Sand the whole area, extending slightly for seamless blending.

Place a straightedge across mended and adjoining flooring. Make sure to inspect the floor for gaps or spaces.

Staining (Optional)

Choose the Right Stain Color

Pick a stain color that complements your desired aesthetic and the room’s overall style. Test the stain on a small, inconspicuous area of the floor or a spare piece of wood.

Apply the Stain Evenly

  • Stir the stain: Thoroughly mix to achieve even color distribution.
  • Apply the stain: Dip an applicator into the stain while following the wood grain. Work in small sections and maintain a wet edge to avoid lap marks. Apply evenly to cover the entire floor.
  • Start in a corner: Start staining from a corner, moving towards the exit to prevent stepping on wet areas.

Wipe Off Excess Stain

After applying the stain, use clean rags or lint-free cloths to remove excess stain. 

Leave the Floor to Dry

Follow the drying time specified by the manufacturer. It takes several hours or overnight for the stain to dry. Ensure the room has proper ventilation during the drying process.

Apply the Finish

1. Choose the Right Type of Finish (oil-based, water-based, etc.)

When choosing a finish, consider durability, appearance, drying time, and ease of application.

Oil-Based Polyurethane Finish

  • Durability: Resistant to scratches, stains, and moisture.
  • Appearance: Adds a warm, amber tone to the wood that darkens over time.
  • Drying time: 24 to 48 hours.

Water-Based Polyurethane Finish

  • Durability: Resistance to scratches, stains, and moisture.
  • Appearance: Has a clear finish that doesn’t darken significantly over time.
  • Drying time: 2 to 4 hours.

Varnish Finish

  • Durability: Resistant to scratches, stains, and moisture.
  • Appearance: Have a clear, glossy finish.
  • Drying time: Varies depending on the specific product. Refer to the manufacturer’s instructions for accurate drying times.

Hardwax Oil Finish

  • Durability: Protection against wear and staining.
  • Appearance: Offer a natural matte or satin finish.
  • Drying time: 24 to 48 hours.

2. Apply the First Coat of Finish

Begin in a corner, moving towards the exit, following the wood grain. Work in small sections using smooth, overlapping strokes for full coverage. Keep sections around 3 to 4 feet wide for a wet edge and seamless blending.

Check for excess finish as you work. Wipe with clean cloths to prevent uneven drying.

3. Buff Between Coats for a Smoother Finish

Buffing eliminates imperfections, but you need to wait until after the first coat dries.

  • Inspect the first coat for imperfections, dust, or raised grain.
  • Attach fine-grit sandpaper and lightly sand along the grain to smoothen rough areas.
  • After buffing, vacuum or sweep, then wipe with a clean, lint-free cloth.

3. Apply Extra Coats for Durability and Depth

Apply more coats based on desired durability and depth. Adding coats increases the finish thickness. Consider height restrictions like door clearances when determining the number of coats.

4. Proper Drying and Curing Times

After the final finish coat, follow the manufacturer’s curing instructions. Curing durations vary, often spanning several days or more. Avoid placing heavy furniture or rugs on the floor during this period to prevent potential marks or damage.

Final Touches

Attach felt or rubber pads to the bottom of furniture legs. They help to prevent scratches and dents when moving or shifting furniture. Replace the pads often to maintain their efficacy.

Tips for Daily Cleaning and Maintenance

Below are some guidelines on how to clean hardwood floors:

  • Use a soft-bristle broom to remove loose dirt, dust, and debris from the floor. You can also use a vacuum cleaner with a floor attachment. It prevents scratches and keeps the floor looking tidy.
  • Use a microfiber dust mop to pick up dust and pet hair from the surface.
  • Use a damp mop or microfiber cloth when the floor requires thorough cleaning. Use a recommended hardwood floor cleaner or mild, PH-neutral solution.
  • Clean up accidental spills to prevent moisture from seeping and staining the floor.
  • Place rugs or mats in high-traffic areas, such as entryways or hallways, to minimize wear and tear on the floor.
  • Avoid using wet mops or excessive water during cleaning. Use mats or rugs near sinks and areas prone to water splashes.
  • If you have pets, trimming their nails helps prevent scratches on the floor’s surface.
  • Excessive sunlight exposure causes discoloration or fading. Use curtains, blinds, or UV-blocking window films to shield the floor.
  • Different wood species and finishes may require specific care instructions. Follow the manufacturer’s guidelines and recommendations for optimal maintenance.