Sanding Cedar Siding Before Refinishing

Cedar siding is valued for its beauty and durability, but over time weathering and old finishes take their toll. Proper sanding prepares cedar siding for new stain or sealer, ensuring even absorption and long-lasting protection. This guide explains how to sand cedar siding correctly without damaging the wood.

Why Sanding Cedar Siding Matters

Cedar develops a gray surface layer from UV exposure. If not sanded away, new finishes won’t bond properly, leading to uneven color and premature peeling. Controlled sanding restores fresh wood for consistent finish application.

Tools You’ll Need

• Random orbital sander or pole sander
• Wet/dry sandpaper sheets (80–150 grit)
• Sanding block for trim and edges
• Vacuum or blower for dust removal
• Exterior stain or sealer

Best Grit Sequence for Cedar

• 80 grit: Removes gray weathering and failed finishes.
• 120 grit: Smooths siding for even stain absorption.
• 150 grit: Optional for decorative siding needing finer prep.

Step-by-Step: Sanding Cedar Siding

1. Prep surface. Wash siding to remove dirt and mildew. Allow to dry completely.
2. Initial sanding. Use 80 grit (25-pack) to strip weathered fibers and rough spots.
3. Smooth surfaces. Switch to 120 grit (50-pack) for uniform finish prep.
4. Optional refinement. For high-visibility areas, finish with 150 grit (100-pack) for a smoother appearance.
5. Clean thoroughly. Remove all dust with blower or vacuum before staining.

Special Cases

Soft cedar can be damaged by over-sanding. Avoid going finer than 150 grit outdoors, as overly smooth surfaces prevent stain absorption. For older siding with deep damage, replace boards rather than oversanding.

Pro Tips

• Sand with the grain to prevent cross scratches that stand out under stain.
• Work in shaded areas—direct sun can dry surfaces too fast during finishing.
• Seal immediately after sanding to avoid new UV damage.

Aftercare

• Re-stain regularly: Every 3–5 years, depending on exposure.
• Spot sand: Use 120 grit for localized repairs before re-coating.
• Keep clean: Wash siding annually to prevent mildew buildup.

FAQs

• Can I use a belt sander? Only on flat panels—cedar dents easily, so orbital sanders are safer.
• Do I need to sand new cedar siding? Light scuff sanding with 120 grit removes mill glaze for better stain absorption.
• What finish works best? Penetrating oil-based stains protect and highlight cedar’s natural beauty.

Watch & Learn

Sanding cedar siding before refinishing brings out fresh wood and ensures lasting protection. With the right grit sequence, your siding will look renewed and stay protected against the elements.