How to Sand Wood Siding Before Painting

Wood siding adds warmth and character to a home, but before repainting, proper sanding is essential. Sanding smooths weathered fibers, removes peeling paint, and ensures new coats adhere evenly. This guide explains how to sand wood siding correctly for lasting paint jobs.

Why Sanding Wood Siding Matters

Without sanding, new paint may blister, peel, or show flaws from the old surface. Controlled sanding removes defects and creates the right texture for primer and paint adhesion, extending the life of the finish.

Tools You’ll Need

• Random orbital sander or pole sander
• Scrapers for heavy peeling paint
• Wet/dry sandpaper sheets (80–150 grit)
• Vacuum or blower for dust removal
• Primer and exterior paint

Best Grit Sequence for Siding

• 80 grit: Removes peeling paint and rough surfaces.
• 120 grit: Smooths siding for primer adhesion.
• 150 grit: Optional for a more refined surface on decorative siding.

Step-by-Step: Sanding Wood Siding

1. Prep the surface. Scrape away loose paint and clean siding to remove dirt and mildew.
2. Initial sanding. Use 80 grit (25-pack) to strip old finish and rough spots.
3. Smooth the wood. Switch to 120 grit (50-pack) for consistent primer-ready surfaces.
4. Optional refinement. For highly visible areas, finish with 150 grit (100-pack) for smoother appearance.
5. Clean thoroughly. Remove dust with blower or vacuum before priming.

Special Cases

Lead paint may be present in older homes—use protective equipment and follow safety guidelines. For cedar siding, avoid sanding too fine, as it reduces paint adhesion.

Pro Tips

• Sand with the grain to avoid cross scratches that show under paint.
• Prime immediately after sanding to prevent weather exposure on bare wood.
• For clapboard siding, sand edges and overlaps carefully for smooth coverage.

Aftercare

• Inspect regularly: Repaint every 7–10 years depending on exposure.
• Touch up: Light sanding with 120 grit before spot repainting keeps siding fresh.
• Wash yearly: Remove dirt and mildew to extend paint life.

FAQs

• Can I paint without sanding? Not recommended—paint won’t adhere well to unsanded, weathered surfaces.
• Do I need to sand all the old paint off? Only loose or peeling areas—sound paint can be scuff-sanded.
• What grit is best before primer? 120 grit provides the ideal balance of smoothness and adhesion.

Watch & Learn

Sanding wood siding before painting ensures smooth coverage and lasting protection. With the right grit sequence and technique, your home’s exterior will stay vibrant and durable for years.