How to Sand and Refinish Wooden Stair Treads for Safety and Style (100–320 Grit Sequence)

Wooden stair treads take a beating from daily foot traffic, leading to worn finishes, scratches, and uneven surfaces. Proper sanding and refinishing can restore their appearance, improve traction, and protect the wood for years to come. This guide walks you through a complete process—from initial smoothing with Grit 100 to a refined finish with Grit 320.

Why Sanding is Important for Stair Tread Refinishing

Daily wear, dirt, and occasional spills degrade wood stair treads over time. Sanding removes surface imperfections and old coatings, ensuring that your new finish adheres evenly and lasts longer while improving the overall safety and appearance of your stairs.

Tools & Materials

• Orbital sander for flat tread surfaces
• Sanding block for edges and corners
• Vacuum and tack cloth
• Multiple grits of sandpaper
• Wood stain or paint
• Protective finish (polyurethane is common for stairs)
• Protective gear: mask, goggles, gloves

Best Grit Sequence for Stair Treads

• Grit 100 — Removing old finish and leveling worn areas
• Grit 180 — Refining the surface after coarse sanding
• Grit 220 — Pre-finish smoothing
• Grit 320 — Final pass for a refined, smooth surface

Step-by-Step Process

1. Preparation. Clear the stairs of all objects and thoroughly clean the treads to remove dust and dirt.
2. Initial sanding. Begin with Grit 100 (50-pack) to remove the existing finish and level uneven areas. Sand with the grain to avoid visible scratches.
3. Surface refinement. Move to Grit 180 (100-pack) to erase coarse sanding marks and smooth the wood.
4. Pre-finish sanding. Use Grit 220 (10-pack) for a final smoothing pass before applying the finish.
5. Final sanding. For a high-end look, finish with Grit 320 (25-pack) to achieve a silky feel.
6. Dust removal. Vacuum thoroughly and wipe with a tack cloth to ensure a clean surface.
7. Apply stain or paint. Evenly coat the treads, following the wood grain. Allow to dry fully before adding the protective topcoat.
8. Apply protective finish. Use thin, even coats of polyurethane for durability. Sand lightly with Grit 320 between coats for the smoothest results.

Special Cases

For older stairs with deep dents or damage, wood filler may be necessary before sanding. Ensure the filler is compatible with your chosen finish.

Pro Tips for Success

• Always sand in the direction of the grain for a cleaner look.
• Replace sandpaper often to maintain cutting performance.
• Consider using a stair tread template to ensure uniform sanding along edges.

Aftercare

• Clean stairs regularly to prevent dirt buildup from scratching the finish.
• Use runners or stair treads for extra protection in high-traffic areas.
• Reapply finish every few years as needed.

FAQs

• Can I sand without removing the old finish? It’s best to remove the finish completely for the most durable results.
• Is it safe to sand stairs indoors? Yes—just make sure to wear protective gear and use dust control methods.

Watch & Learn

By following this grit progression—from Grit 100 (50-pack) to Grit 320 (25-pack)—you can transform worn stair treads into safe, beautiful, and long-lasting features in your home.