How to Sand Wood Floors Before Refinishing: Complete Grit Guide

Refinishing hardwood floors is one of the most rewarding home improvement projects—but only if the sanding is done right. Skipping steps or using the wrong grit sequence can lead to uneven stain absorption, swirl marks, or peeling finishes. This guide covers the best way to sand wood floors for a professional result.

Why Sand Wood Floors?

Floor sanding removes old finish, scratches, dents, and stains while leveling the surface. It also opens the wood grain so that stain and polyurethane can bond evenly. Without proper sanding, even the best finish will fail prematurely.

Tools You’ll Need

• Drum sander for large areas
• Edger sander for corners and walls
• 9x11 in sandpaper sheets for detail work
• Vacuum and tack cloth
• Safety gear: respirator, ear protection, knee pads

Best Grit Sequence for Floors

• 60 grit: Heavy stripping of old finish and leveling high spots.
• 100 grit: Mid-level smoothing and scratch removal.
• 150 grit: Final blending before stain or polyurethane.

Step-by-Step: Sanding Hardwood Floors

1. Prep the room. Remove furniture, cover vents, and clean debris.
2. First pass with 60 grit. Use 60 grit (25-pack) for aggressive stripping. Work in straight lines with the drum sander.
3. Edge the perimeter. Switch to an edger with 100 grit (50-pack) to reach corners and walls.
4. Second pass with 100 grit. Run the drum sander again to refine the surface and remove 60 grit scratches.
5. Final pass with 150 grit. Apply 150 grit (100-pack) for a smooth, even finish ready for stain.
6. Clean thoroughly. Vacuum dust between each grit and wipe with tack cloth before applying finish.

Special Cases

If the floor has deep stains or pet damage, additional passes with coarse grit may be required. For engineered wood, avoid aggressive sanding as the veneer is thin.

Pro Tips

• Sand in the direction of the wood grain to avoid cross-grain scratches.
• Replace sandpaper often—dull sheets burnish instead of cutting.
• Test stain on a small section before applying to the entire floor.

Aftercare

• Allow polyurethane to cure fully before moving furniture back.
• Use felt pads on furniture legs to prevent scratches.
• Clean with a hardwood-safe cleaner, not water or harsh chemicals.

FAQs

• Do I need to remove all old finish? Yes—stain and polyurethane will not adhere to old coatings.
• Can I use a random orbital sander? Yes, but it’s slower. Best for small rooms or touch-ups.
• What grit before staining? 150 grit ensures the best absorption and smoothness.

Watch & Learn

Get eQualle’s 9x11 in sandpaper sheets for edging, detail sanding, and hand finishing. Designed for wet or dry use, available in 25, 50, and 100 packs. Shop wood sanding sheets here.