How to Sand Wooden Decks Before Sealing or Staining (60, 80, 120, 150 Grit Guide)

Outdoor wooden decks face constant exposure to sun, rain, and foot traffic. Over time, they develop rough spots, splinters, and worn finishes. Sanding is the first step to restoring comfort and beauty before sealing or staining. With the right grit sequence, you can achieve smooth, long-lasting results. This guide explains how to sand decks step by step using 60, 80, 120, and 150 grit sandpaper.

Why Sanding Decks Matters

Weathered wood has raised fibers and old coatings that prevent even stain absorption. Sanding smooths splinters, removes flaking finishes, and opens the wood grain for better penetration. Without sanding, new coatings may peel or look blotchy.

Tools You’ll Need

• 60–150 grit sandpaper – coarse to medium for outdoor prep.
• Orbital or floor sander – speeds up sanding on large decks.
• Sanding block or sponge – for railings and edges.
• Vacuum & leaf blower – to clear dust after sanding.
• Deck stain or sealer – protects and enhances the wood.

Best Grit Sequence for Deck Sanding

• 60 grit: Removes weathered fibers and old coatings.
• 80 grit: Smooths rough areas after coarse sanding.
• 120 grit: Refines the surface for stain absorption.
• 150 grit: Creates a smooth, splinter-free surface for sealing.

Step-by-Step Deck Sanding

1. Start with 60 grit. Strip weathered fibers and old coatings using 60 grit (25-pack).
2. Move to 80 grit. Smooth out rough boards with 80 grit (50-pack).
3. Refine with 120 grit. Prepare wood for stain using 120 grit (25-pack).
4. Finish with 150 grit. Lightly sand to create a comfortable walking surface with 150 grit (100-pack).
5. Clean thoroughly. Blow off dust and vacuum before applying sealer or stain.

Special Cases

For painted decks, start with 40 grit to strip heavy paint before moving to 60 grit. For softwoods like pine, avoid sanding above 150 grit—too fine and stain won’t absorb well. For hardwood decks, finish at 180 grit for a refined look.

Pro Tips

• Sand in the direction of the grain to avoid scratches.
• Work in sections for consistent results.
• Always wear safety glasses and a dust mask outdoors.
• Seal immediately after sanding to protect exposed wood fibers.

Aftercare

• Reapply sealer every 1–2 years to protect against UV and moisture.
• Clean decks regularly to prevent mold and dirt buildup.
• Touch up with light sanding and resealing in high-traffic areas.

FAQs

• Can I pressure wash instead of sanding? No—washing raises wood fibers, sanding smooths them down.
• What grit is best for splinter removal? 60–80 grit removes splinters effectively.
• Do I need to sand new wood decks? Yes—mill glaze must be sanded off before staining.

Watch & Learn

For outdoor refinishing projects, explore our extra coarse and coarse sandpaper collection.