How to refinish wood floors? Step-by-step guide

Refinishing your wood floors can dramatically transform the look and feel of your home, restoring their original beauty and extending their lifespan. Over time, hardwood floors can become dull, scratched, or discolored due to wear and tear, sun exposure, and spills. While it’s a significant project, refinishing allows you to bring back their luster, change their stain color, and protect your investment for years to come. This comprehensive guide will walk you through the step-by-step process of refinishing wood floors, from preparation to the final touches, empowering you to achieve a professional-looking result.

Tools and materials you’ll need

Before embarking on your floor refinishing project, gathering all the necessary tools and materials is crucial. Having everything on hand will ensure a smoother, more efficient, and safer process.

Safety gear:

• Respirator (N95 or higher): Absolutely essential for protecting your lungs from fine wood dust.
• Safety Glasses/Goggles: To protect your eyes from dust and debris.
• Hearing Protection: Sanding machines are very loud.
• Work Gloves: To protect hands during various stages.

Sanding equipment (Can often be rented from a home improvement store):

• Drum Sander (or Belt Sander): The primary machine for sanding large open areas.
• Edge Sander (or Orbital Edge Sander): For sanding close to walls and in corners where the drum sander cannot reach.
• Orbital Palm Sander (or Detail Sander): For very tight corners, stairs, or intricate areas.
• Assortment of Sandpaper Grits:
  • Coarse (40-60 grit): For initial removal of old finish and deep imperfections.
  • Medium (80-100 grit): For smoothing out marks from the coarse grit.
  • Fine (120-150 grit): For final smoothing before staining/finishing.
  • Note: Always follow the sander manufacturer’s recommendations for grit progression.

Cleaning and prep tools:

• Heavy-Duty Shop Vacuum: With a fine dust filter and hose attachments for thorough dust removal.
• Broom and Dustpan: For initial debris removal.
• Hammer and Nail Set: For setting protruding nails.
• Putty Knife/Scraper: For removing old caulk or stubborn debris.
• Painter’s Tape: For masking off areas not being refinished.
• Plastic Sheeting/Drop Cloths: To seal off rooms and protect surfaces.
• Tack Cloths: For wiping away fine dust before staining/finishing.

Staining and finishing materials:

• Wood Stain (if desired): Oil-based or water-based, depending on preference and finish compatibility. Purchase extra.
• Wood Floor Finish (Polyurethane, Water-Based, etc.): Purchase sufficient quantity for 2-3 coats, plus extra.
• Applicator Pads/T-Bar Applicator: For applying finish evenly.
• Natural Bristle Brush (for oil-based) or Synthetic Brush (for water-based): For cutting in edges.
• Clean Rags: For stain application and wiping.
• Stir Sticks: For mixing stain and finish.
• Paint Tray (or larger roller pan): For pouring stain/finish.

Repair materials:

• Wood Filler (Non-shrinking, sandable, stainable if applicable): For filling small holes or gaps.
• Replacement Wood Planks (if necessary): To match existing flooring for repairs.
• Wood Glue: For securing loose planks.

Preparing the room for refinishing

Proper preparation is paramount for a successful and clean refinishing job. Don’t skip these steps; they will save you headaches later.

1. Empty the Room Completely: Remove all furniture, rugs, curtains, and wall hangings. Even small items can get damaged or become dust traps.
2. Remove Old Flooring (if applicable): If there’s old carpet, linoleum, or other flooring over the hardwood, remove it. Carefully pull out all staples, nails, and adhesive.
3. Clear Protruding Obstructions:
   • Remove Baseboards/Shoe Molding: Carefully pry off baseboards and shoe molding. Label them to reinstall in the same spot. This allows you to sand fully to the wall.
   • Set Nails: Use a hammer and nail set to tap down any protruding nails or screws below the wood surface. Any exposed metal will tear sandpaper and can cause sparks.
4. Repair Damaged Boards:
   • Loose Boards: Secure any loose floorboards by screwing them into the subfloor or nailing them with finish nails.
   • Damaged/Rotten Boards: Replace any severely damaged, rotten, or warped boards. Cut out the old section neatly and replace it with a new piece of matching wood, ensuring it’s properly secured and flush.
   • Fill Minor Gaps/Holes: Use a sandable, non-shrinking wood filler to fill small nail holes, minor cracks, or gaps between boards. Allow it to dry fully, then sand smooth. Note: For wider gaps between planks, especially in older floors, some pros recommend leaving them unfilled to allow for natural wood movement.
5. Clean the Floor Thoroughly: Sweep and vacuum the entire floor to remove all loose dirt, dust, and debris. The cleaner the floor is before sanding, the better the sandpaper will perform.
6. Seal Off Adjacent Areas: Dust from sanding is extremely fine and gets everywhere.
   • Tape Plastic Sheeting: Use painter’s tape and plastic sheeting to seal off doorways, cabinets, built-ins, and vents in the room. Cover light fixtures and any non-removable items.
   • Turn Off HVAC: Turn off your heating, ventilation, and air conditioning system to prevent dust from circulating throughout your home.
7. Ensure Proper Ventilation: Open windows (if weather permits and not dusty outside) to allow for air circulation during sanding, staining, and finishing. Use fans to direct airflow out of the room.

Sanding the wood surface

Sanding is the most critical and physically demanding part of refinishing. It removes the old finish, smooths imperfections, and prepares the wood for a new stain or finish.

1. First Pass (Coarse Grit – 40 or 60 grit):
   • Purpose: To remove the old finish, deep scratches, and imperfections.
   • Technique (Drum Sander): Start in a corner, ensuring the drum is raised. Turn on the machine and slowly lower the drum as you move forward at a steady pace. Walk slowly and evenly with the grain of the wood. At the end of the pass, slowly raise the drum before turning the machine. Overlap each pass by a few inches.
   • Edge Sander: Use the edge sander with the same coarse grit to sand along the perimeter of the room where the drum sander couldn’t reach. Keep it moving to avoid creating divots.
   • Palm Sander: Use a palm sander with coarse grit in corners and very tight spots.
   • Dust Bag: Frequently empty the dust bag on your sanders.
2. Second Pass (Medium Grit – 80 or 100 grit):
   • Purpose: To remove the swirl marks and scratches left by the coarse grit.
   • Technique: Repeat the same sanding process (drum, edge, palm sanders) using the medium grit paper. This pass should make the floor much smoother.
3. Final Pass (Fine Grit – 120 or 150 grit):
   • Purpose: To prepare the wood for staining and finishing, creating a perfectly smooth surface.
   • Technique: Use the fine grit paper with all sanders. This pass should leave the wood feeling silky smooth. Pay extra attention to blending the edges with the main floor.
4. Thorough Cleaning After Each Pass: After each sanding pass (and especially the final one), meticulously clean the entire room.
   • Vacuum: Use a heavy-duty shop vacuum with a brush attachment to vacuum every inch of the floor, including corners and crevices.
   • Wipe Down: Use a tack cloth or a microfiber cloth dampened with mineral spirits (for oil-based finishes) or water (for water-based finishes) to wipe down the entire floor. This removes fine dust particles that the vacuum missed. Change cloths frequently until no dust residue is visible. Any dust left behind will be trapped in your finish.

Applying stain and finish

Once the floor is perfectly smooth and dust-free, it’s time to apply your chosen stain (if desired) and the protective finish.

A. Applying Wood Stain (Optional):

1. Test Stain: Always test your chosen stain on an inconspicuous area of the actual floor (e.g., inside a closet or under a baseboard) or on a scrap piece of the same wood species. This allows you to see the true color before applying it to the entire floor.
2. Apply Evenly: Work in small sections (e.g., 3×3 feet or 1 meter x 1 meter). Apply the stain evenly with a brush or clean rag, working with the grain.
3. Wipe Excess: After a few minutes (follow manufacturer’s instructions for “open time”), use a clean, dry rag to wipe off any excess stain. This is crucial for even color. If you leave too much stain on, it won’t absorb properly and can create a blotchy look.
4. Overlap Properly: Ensure smooth overlaps between sections to avoid lap marks.
5. Allow to Dry Fully: Allow the stain to dry completely according to the manufacturer’s instructions (often 24-48 hours). Proper drying time is critical before applying the finish. Ensure good ventilation.

B. Applying Wood Floor Finish (Polyurethane, etc.):

1. First Coat (Sealer/Primer Coat):
   • Ventilation: Ensure good ventilation in the room (open windows, use fans, but direct air out of the room to avoid blowing dust in).
   • Apply Evenly: Pour a manageable amount of finish into a clean paint tray or roller pan. Use a T-bar applicator or a quality floor finish applicator pad. Work with the grain of the wood, applying thin, even coats.
   • Cut In Edges: Use a good quality brush to “cut in” along the edges of the room and around any obstacles where the applicator won’t reach.
   • Work Your Way Out: Start in the corner farthest from your exit and work your way out of the room, ensuring you don’t paint yourself into a corner.
   • Cure Time: Allow the first coat to dry completely according to the manufacturer’s instructions (usually 4-8 hours for water-based, 12-24 hours for oil-based).
2. Light Sanding Between Coats (Optional but Recommended for Smoothness):
   • After the first coat is dry, light sand the entire floor with a very fine-grit screen (220-320 grit) on a pole sander. This helps to smooth out any imperfections or raised grain.
   • Crucially, vacuum and tack-cloth clean the floor again after this light sanding to remove all dust.
3. Second and Third Coats:
   • Apply the second and (if desired) third coats of finish following the same application technique.
   • Allow each coat to dry completely between applications. More coats generally mean more durability.

Maintenance after refinishing

Proper care after refinishing is vital to protect your newly beautiful floors and extend the life of the finish.

1. Cure Time:
   • Light Foot Traffic: Avoid light foot traffic for at least 24-48 hours after the final coat.
   • Furniture: Wait at least 72 hours (3 days) before moving furniture back onto the floor. Use felt pads under all furniture legs to prevent scratches.
   • Rugs: Do not put area rugs back for at least 1-2 weeks to allow the finish to fully cure and off-gas. Placing rugs too soon can lead to discoloration or prevent proper curing.
   • Heavy Objects/Pets: Avoid dragging heavy objects or allowing pets with untrimmed nails on the floor for at least a week.
2. Regular Cleaning Routine:
   • Sweep/Dust Mop Daily: Regularly sweep or dust mop your floors with a microfiber dust mop to remove dirt, dust, and grit. This is the most important step to prevent micro-scratches that dull the finish.
   • Vacuum: Use a vacuum with a hard floor attachment (never a beater bar) for more thorough cleaning.
   • Damp Mop (Sparingly): When necessary, use a barely damp mop with a pH-neutral, hardwood-specific floor cleaner. Avoid excessive water, as it can damage the finish and wood.
   • Avoid Harsh Cleaners: Never use abrasive cleaners, ammonia-based cleaners, oil soaps, or steam mops on your refinished hardwood floors. These can dull, strip, or damage the finish.
3. Protect from Scratches and Dents:
   • Felt Pads: Place felt pads on the bottom of all furniture legs. Check and replace them periodically.
   • Area Rugs: Use area rugs in high-traffic areas (entryways, in front of sinks, under dining tables) to protect the finish. Ensure they have breathable backings that won’t trap moisture.
   • No Shoes Inside Policy: Encourage family and guests to remove outdoor shoes, which track in dirt, grit, and moisture.
   • Pet Nails: Keep pet nails regularly trimmed to minimize scratches.
4. Manage Humidity: Maintain consistent indoor humidity levels (ideally 35-55% relative humidity) using a humidifier in dry winter months and a dehumidifier/AC in humid summer months. This prevents excessive expansion and contraction of the wood, which can lead to gapping or cupping.
5. Spot Clean Spills Immediately: Wipe up any spills (especially water, pet accidents, or acidic liquids) as soon as they happen to prevent staining or moisture damage.
6. Professional Recoating: Depending on foot traffic, consider having your floors professionally “screened and recoated” every 3-5 years. This process involves lightly abrading the top coat and applying a fresh layer of finish, which can significantly extend the time before a full refinish is needed again.

Refinishing wood floors is a rewarding project that can significantly enhance your home’s beauty and value. With careful preparation, proper technique, and diligent maintenance, your newly refinished floors will shine for many years to come.

Ready to bring your hardwood floors back to life? Sky Hardwood Floors specializes in expert hardwood floor refinishing, restoring the beauty and durability of your existing floors with precision and care. Contact us today for a free consultation and let us help your floors shine!