Hardwood floors can be refinished multiple times over their 50+ year lifespan — restoring scratched, worn, or outdated floors to like-new condition. The process: sand off the existing finish (and slightly the wood surface), stain (optional), apply new clear topcoat. The job requires specialty equipment (drum sander, edge sander) typically rented for the project. Professional finishers do this in 2 days; DIY takes 3-5 days with rented equipment.

This guide covers a complete refinishing of solid hardwood. Engineered hardwood with thin top veneer cannot be refinished or only once before reaching the substrate.

Before you start

Three things to settle:

1. Equipment rental. You'll need three rental machines: a drum sander for the field, an edge sander for the perimeter and around obstacles, and a vacuum for dust. Most rental shops bundle these by the day, so plan rental days around your project length. Budget separately for sandpaper grits and finish products.

2. Plan to vacate the home. Refinishing produces tremendous dust during sanding and toxic fumes during stain/finish. Plan to live elsewhere for 3-5 days. Family with allergies or respiratory issues should especially avoid the home during work.

3. Containment is critical. Dust travels everywhere. Even with HEPA filters and zip walls, expect to find sanding dust in the rest of the home for weeks. Use plastic sheeting to seal off the work area; cover or remove all furniture, art, electronics.

What you'll need

Tools

Drum sander (rented)
Edge sander or random orbit sander (rented)
Shop vacuum with HEPA filter
Putty knife
Paint brush and roller (for finish)
Lambswool applicator (for finish)
Tape measure and pencil
Respirator (organic vapor + particulate filter)
Knee pads
Painter's tape
Plastic sheeting

Materials

Sandpaper grits: 36 (rough), 60 (medium), 80, 100 (fine), 120 (final)
Wood filler (for nail holes and gaps)
Stain (if changing colour)
Polyurethane (oil-based or water-based, 3 coats)
Tack cloth (for dust between coats)

Move out for the duration

Refinishing is among the most-disruptive home projects. Sanding produces fine wood dust that infiltrates everywhere. Finish products release toxic fumes (oil-based polyurethane especially).

Plan to vacate the house for 3-5 days — the work plus 2 days of off-gassing after the final coat. Returning earlier exposes residents to harmful fumes.

Step-by-step instructions

Prepare the room

Remove all furniture, area rugs, and wall art.

Cover or remove all electronics.

Seal off doors with plastic sheeting and zip walls. Cover HVAC registers.

Inspect floor and prep

Walk the floor and identify problems: deep scratches, gaps, popped nails, damaged boards.

Drive any popped nails below the surface with a nail punch.

Replace damaged boards if needed (significantly more involved — best done before sanding).

Sand with coarse grit (36 grit)

Start with the drum sander loaded with 36 grit sandpaper. This grit removes the existing finish and any deep stains.

Sand in the direction of the wood grain. Move steadily; don't pause in one spot (drum sanders gouge).

Use the edge sander to reach areas the drum can't (perimeter, around obstacles).

Progress through grits

Vacuum thoroughly between grits (sandpaper grit changes are NOT optional — skipping grits leaves visible scratches in the finish).

60 grit: smooths the rough sanding from 36.

80 grit: further refining.

100 grit: nearing final smoothness.

120 grit: final smoothing, ready for finish.

Vacuum and tack

After final sanding, vacuum the entire floor thoroughly using a HEPA filter.

Wipe with tack cloth to pick up final dust.

Don't apply finish over any visible dust — it'll trap in the finish forever.

Apply stain (optional)

If changing the floor's colour, apply stain per its instructions. Use a lambswool applicator or rags.

Wipe excess stain with clean rags before it dries.

Let stain dry per package — typically 8-24 hours.

Apply first coat of finish

Apply polyurethane finish with a lambswool applicator, working with the grain. Thin even coats.

Oil-based polyurethane: amber tint, longer cure, more durable. 24-hour cure between coats.

Water-based polyurethane: clear (no amber), faster cure (4-6 hours), slightly less durable.

Sand between coats with 220 grit

After first coat is fully dry, hand sand or use a random orbit sander with 220 grit. Just light sanding to scuff the surface — provides bond for next coat.

Vacuum and tack before applying next coat.

Apply 2-3 additional coats

Three coats total typical. Some installations use four for high-traffic areas.

Sand and tack between each coat.

Final coat: don't sand. Let cure undisturbed.

Cure 5-7 days before heavy use

Light foot traffic (sock feet) acceptable after 24-48 hours.

Heavy use (furniture, area rugs, regular foot traffic): wait 5-7 days.

Full chemical cure: 30 days. Stay off as much as possible during this period.

Common mistakes that cost you

Skipping grits. Visible scratches show through finish. Progress through 36, 60, 80, 100, 120.
Not vacuuming between grits. Coarse grit residue gouges with finer grits. Vacuum thoroughly each transition.
Drum sander pauses. Gouges the floor. Move steadily; don't stop in one spot.
Working without respirator. Wood dust and finish fumes are toxic. Always wear respirator.
Furniture too soon. Finish needs full cure. Wait 5-7 days for normal use, 30 days for heavy use.
DIY without rental equipment. Hand-held sanders can't achieve drum sander's effect. Rent the right tools.

Frequently asked questions

Should I refinish or replace?

Refinish if: hardwood is solid (not engineered with thin veneer), in good condition, scratches don't go through to subfloor.

Replace if: floor is damaged beyond refinishing, water damaged, was already refinished multiple times (each refinish removes 1/16 inch of wood).

How long does professional refinishing take?

Professional crews: 2 days for sanding + 1 day for staining + 2-3 days for finish coats.

DIY: 3-5 days plus rental equipment time.

Oil-based or water-based polyurethane?

Oil-based: more durable, amber colour (warms wood tone), longer cure, stronger fumes.

Water-based: clear (no amber), faster cure, less smell, slightly less durable.

Most modern homeowners choose water-based for the cleaner application.

When to call us instead

Hardwood refinishing is most-often hired out to specialists. The equipment, dust management, and skill required favour professional work. We coordinate refinishing as part of larger renovations.

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