Before You Begin Refinishing Your Hardwood FloorsLook inside a vent or along a baseboard to make sure your floors are 3/4-inch solid hardwood, not engineered hardwoods. Refinishing engineered wood should be left to the pros as it consists of several wood layers that are easily damaged.
If you’re not sure if your hardwood floor needs refinishing, put a few drops of water on it. If the water beads or soaks in slowly over a few minutes, you probably just need a good cleaning and polishing. However, if the water soaks in immediately, it’s time for a refinish.
If your floor is damaged, stained or has wax over the finish, you’ll need to sand to bare wood.
Tip: Wear goggles, gloves, kneepads, hearing protection, and a respirator or dust mask during this project.
Prep the Hardwood Floor for Sanding
Prep the Area
Clear the room of furniture, drapes, pictures, and register covers. Remove the doors.
Label the Shoe Moulding
Label the shoe moulding using painter’s tape to mark corresponding pieces and walls with a numbered or lettered system — a 1 on the shoe moulding, a 1 on the wall, and so forth. Then, remove the labeled shoe moulding with a pry bar.
Remove the Staples & Fasteners
Inspect the floor closely. Drive in all nail heads and remove any carpet staples or fasteners from former flooring. Fasteners tear the paper on floor sanders.
Put Up Plastic Sheeting
Cover the vents, light fixtures, and doorways with plastic. Old sheets will also work. Tape thoroughly around the edges.
Sanding Hardwood Flooring - Part 1
Sanding your hardwood floors takes three sessions with progressively lighter grit sandpaper. To begin, use a coarse 30-40 grit, then a medium 50-60 grit, and finally a fine 80-100 grit.
For flat floors, use a random orbital sander. This sander is easier to handle than a drum sander and eliminates directional scratches. Random orbital sanders are available for rent. For cupped or wavy floors, a drum sander is required. Since drum sanders are harder to handle and open the door for potential marring, you may consider hiring a professional.
Note: Never skip more than one sandpaper grade in each sanding session.
Sand the First Layer
Begin in the farthest corner from the door. Load the sander with 30-40 grit sandpaper. Start the sander and immediately begin moving along the grain, one row at a time. Failure to begin sanding immediately will damage the floor.
Overlap the First Layer
When you get to the end of the room, move over and pull back, slightly overlapping the first pass by a few inches. Continue sanding, getting as close to the edges as possible.
Note: Do not let the bag fill more than halfway before emptying. Otherwise the additional weight of the dust negatively affects the sanding of the floor. Plus, the bag will be lighter and easier to handle.
Sand the Edges
After sanding the room’s centre, sand the edges using a power hand sander loaded with 30-40 grit sandpaper.
Use the Detail Sander in the Corners
In the corners, use a detail sander also loaded with 30-40 grit sandpaper.
Vacuum the Dust From the First Pass
Once the first pass of sanding is complete, vacuum thoroughly with a brush attachment.
Fill Holes & Gouges
Examine the floor. Fill any gouges or holes with matching wood filler.
Sanding Hardwood Flooring - Part 2
Make Pencil Marks to Keep Track
To help keep track of your sanding with the second pass, make light pencil marks along the edges of the room. You’ll see where you’ve sanded as you sand away the marks.
Start with Medium Grit Sandpaper
Load your random orbital and hand sanders with medium, 50-60 grit sandpaper.
Sand the Floor
Follow the same process and pattern as the first pass. Use the random orbital sander in the room's centre, the hand sander along the edges, and the detail sander in the corners.
Thoroughly vacuum the room with a brush attachment.
Sanding Hardwood Flooring - Part 3
Move on to Fine Grit Sandpaper
Load the sanders with a fine 80-100 grit sandpaper. The fine texture creates a smooth surface.
Sand the Floor
Follow the same process and pattern as the first and second pass, using the hand sander around the edges and the detail sander in the corners.
Clean All the Dust
Vacuum thoroughly using a brush attachment and damp mop to pick up any remaining particles on the floor. Use a damp rag to wipe away excess dust from windows, sills, and other structural edges around the room.
Buff with 120-Grit Screen
If the floor feels rough after sanding with the 100-grit paper, buff it with a 120-grit screen. Buffing with a screen helps smooth out fine scratches. Follow the same pattern as sanding, working along the grain and getting as close to the wall as possible.
Use a sanding screen on an extension pole for the room's edges and corners.
Final Steps to Refinishing Hardwood Flooring
Thoroughly Clean the Room
Vacuuming and wiping away excess dust from walls, windowsills, fans, and other fixtures.
Clean the Floor
Wipe the floor with a cloth dampened with mineral spirits.
Note: Check local fire regulations and with your local solid waste department for disposal instructions.
Staining the floor is only necessary if you want to change the floor colour. To do so, apply a pre-stain conditioner and stain according to the manufacturer’s instructions.
Begin staining at the farthest corner from the door and work toward the exit so as to not stain yourself into a corner of the room.
If you’re not staining the floor, apply a sanding sealer starting in the farthest corner of the room. Let it dry according to the manufacturer’s instructions, then lightly sand with 320-grit sandpaper.
Vacuum the entire room again and clean the floor with a tack cloth.
Tip: It's essential to have a dust-free room prior to polyurethane application.
How to Apply Clear Polyurethane to Hardwood Flooring
Finish the project with an application of polyurethane. Polyurethane has a strong odour, so make sure to open doors and windows for ventilation throughout your home. Some polyurethane adds an amber tone to wood. Check the label before buying and application to ensure your desired colour and sheen.
Prep the Polyurethane
Stir the polyurethane thoroughly. Do not shake the can as this may cause bubbles.
Make Sure the Stain Applicator is Clean
Remove excess fibers from the stain applicator with tape. Likewise, remove any loose bristles from your natural-bristle brush.
Apply the Polyurethane
Using smooth strokes, apply the polyurethane starting at the edge of the room, with the natural-bristle brush, in the farthest corner from the door. Maintain a wet edge and move slowly and deliberately to avoid creating bubbles in the polyurethane.
Use the stain applicator as you move toward the centre of the room. With each pass, overlap your strokes slightly to feather the starts and stops together for a more uniform coat.
Put on a Second Coat of Polyurethane
Let the polyurethane dry according to the manufacturer’s instructions, and then apply a second coat.
Tip: Some products require sanding between coats. Refer to your product’s instructions for application.
Check That Your Floor is Dry
Let the second coat dry for a few days, per the product’s labelled instructions, then check the tackiness of the floor. If the floor is sticky to the touch, allow more drying time.
Reattach the Baseboards, Shoe Mouldings & Transitions
Wearing soft, flat shoes that won’t damage your new floor, reattach the baseboards, shoe mouldings, and transitions you removed during the refinishing process.
Put Your Furniture Back
Replace your furniture, but do not slide anything across the floor to avoid re-scratching the surface.
Tip: Applying felt pads to furniture and table legs helps prevent future scratching and scuffing.
A Note on Removing Other Flooring
If you've decided it's time to remove the carpet and enjoy the hardwoods underneath, remember:
- Some carpet pads can be a challenge to remove. Use an adhesive remover to dissolve the carpet adhesive. Remove the carpet tack strips around the perimeter of the room. If the resulting holes won't be covered by moulding, fill them with a wood filler putty prior to sanding.
- Carefully remove any staples or nails to prevent damage to tools and the floor itself. If nails can't be pulled, use a nailset to sink them below the floor surface.
- Even a resilient floor, such as vinyl or linoleum, can be removed, although it may be difficult. Pull up as much as possible. Use adhesive remover to remove the flooring adhesive. If scraping is necessary (it probably will be) take care not to gouge the wood with the scraper. If you do gouge the wood, use wood filler to correct the mistake prior to sanding.
Note: Older resilient floors (up to the 1970s and 1980s) made from vinyl or linoleum may also contain asbestos. If you are unsure, DO NOT SAND. Contact an asbestos-removal company.
How To Terms
- Prep the Hardwood Floor for Sanding
- Prep the Area
- Label the Shoe Moulding
- Remove the Staples & Fastners
- Put Up Plastic Sheeting
- Sand the First Layer
- Overlap the First Layer
- Sand the Edges
- Use the Detail Sander in the Corners
- Vacuum the Dust From the First Pass
- Fill Holes & Gouges
- Sanding Hardwood Flooring - Part 2
- Make Pencil Marks to Keep Track
- Start with Medium Grit Sandpaper
- Sand the Floor
- Sanding Hardwood Flooring - Part 3
- Move on to Fine Grit Sandpaper
- Sand the Floor
- Clean All the Dust
- Buff with 120-Grit Screen
- Final Steps to Refinishing Hardwood Flooring
- Thoroughly Clean the Room
- Clean the Floor
- Prep the Polyurethane
- Make Sure the Stain Applicator is Clean
- Apply the Polyurethane
- Put on a Second Coat of Polyurethane
- Check That Your Floor is Dry
- Reattach the Baseboards, Shoe Mouldings & Transitions
- Put Your Furniture Back
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