How to Sand Wooden Stairs for Painting (80, 120, 150, 220 Grit Guide)

Wooden stairs often take a beating from heavy foot traffic, leaving behind scratches, dents, and old finishes. Sanding is a crucial step before painting to ensure durability and a smooth finish. With the right grit progression, you’ll create a surface that holds paint evenly and lasts for years. This guide explains how to sand stairs step by step using 80, 120, 150, and 220 grit sandpaper.

Why Sanding Stairs Matters

Painting over unsanded wood leaves behind imperfections and causes poor adhesion. Sanding removes old coatings, levels dents, and creates the proper texture for primer and paint. Without this step, paint may peel or chip quickly.

Tools You’ll Need

• 80–220 grit sandpaper – coarse through fine for stair prep.
• Orbital sander or detail sander – efficient for flat treads and edges.
• Sanding block – for corners and risers.
• Vacuum & tack cloth – to clean between stages.
• Primer & paint – for sealing and finishing stairs.

Best Grit Sequence for Stair Sanding

• 80 grit: Removes heavy finishes and deep scratches.
• 120 grit: Smooths after coarse sanding.
• 150 grit: Refines surface before priming.
• 220 grit: Final sanding for smooth, paint-ready wood.

Step-by-Step Stair Sanding

1. Start with 80 grit. Strip old finishes and rough damage using 80 grit (50-pack).
2. Smooth with 120 grit. Refine surfaces evenly using 120 grit (25-pack).
3. Refine with 150 grit. Prepare wood for primer using 150 grit (25-pack).
4. Finish with 220 grit. Lightly sand for a smooth, paint-ready surface with 220 grit (100-pack).
5. Clean thoroughly. Vacuum and wipe stairs before priming and painting.

Special Cases

For hardwood stairs like oak or maple, finishing at 180 grit may be enough before primer. For softwoods like pine, finishing with 220 grit helps achieve smoother paint coverage. If multiple paint layers exist, consider stripping before sanding.

Pro Tips

• Sand with the grain of the wood to avoid scratches.
• Use sanding sponges for curved edges and detailed trim.
• Seal immediately after sanding to prevent dust contamination.
• Replace sheets frequently—stairs wear sandpaper quickly.

Aftercare

• Inspect stairs annually and touch up scratches promptly.
• Clean with gentle wood-safe products to preserve finish.
• Repaint every few years for long-lasting results.

FAQs

• Can I paint stairs without sanding? Not recommended—paint adhesion will be poor.
• What grit should I use before primer? 150–220 grit provides the best adhesion.
• Can I use a belt sander? Only on large, flat treads—detail sanders are better for edges.

Watch & Learn

For durable stair refinishing, explore our wood sanding collection.