DIY Deck Refresh: Cleaning, Sanding, and Staining a Wooden Deck

A wooden deck is a wonderful space for outdoor entertaining, but constant exposure to rain, sun, and snow will weather the wood. Over time, UV rays turn wood gray, and moisture leads to mold, mildew, and splintering.

Tearing down a weathered deck and building a new one costs thousands of dollars. Instead, you can restore a tired deck yourself for under $200 in materials. Here is our step-by-step guide to cleaning, sanding, and staining a deck.

Table of Contents

1. Inspecting and Prepping the Wood
2. Cleaning: Power Washing vs. Deck Cleaners
3. Sanding Off Splinters
4. Applying Deck Stain and Sealer
5. Tools & Materials Checklist
6. FAQs

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1. Inspecting and Prepping the Wood {#inspecting-prep}

Before cleaning, check the structure:

• Check for Rot: Poke the structural joists and posts under the deck with a flathead screwdriver. If the wood feels soft or crumbly, it is rotted and must be replaced.
• Secure Loose Screws: Walk the deck and drive down any raised screw heads or nail heads to prevent foot injuries.

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2. Cleaning: Power Washing vs. Deck Cleaners {#cleaning}

To ensure the new stain adheres, you must strip away gray, weathered wood fibers and mildew.

• Using Deck Cleaner: Apply a specialized wood deck cleaner containing sodium percarbonate (available at home centers). Scrub the wood with a stiff-bristled broom, and rinse.
• Power Washer Caution: If using a power washer, keep the pressure below 1,500 PSI and keep the wand moving constantly. High pressure can carve deep grooves into soft pine or cedar decking, ruining the surface.

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3. Sanding Off Splinters {#sanding}

Sanding opens up the wood pores so the stain can penetrate.

• Floor Sander: Rent a random orbital floor sander from a local hardware store for large decks, or use a handheld belt sander for small decks.
• Sanding Grits: Use 80-grit sandpaper for the deck floorboards. Avoid using fine grits like 150, as they close up the wood pores and prevent the stain from absorbing.

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4. Applying Deck Stain and Sealer {#staining}

Choose the right stain type:

• Solid Color Stain: Behaves like thin paint. It hides wood grain and offers the best UV protection, but can peel over time.
• Semi-Transparent Stain: Highlights the wood grain while adding color. It won't peel but needs re-application every 2 to 3 years.
• Application: Use a natural-bristle stain brush to work the stain into the joints between boards. Apply two thin coats.

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5. Tools & Materials Checklist {#tools-materials}

• Sodium Percarbonate Deck Cleaner: For removing mold.
• Exterior Deck Stain (2-3 Gallons): Choose premium brands like Cabot or Behr.
• Handheld Orbital Sander: With 80-grit sanding discs.
• Safety Gear: Safety goggles and gloves.

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6. FAQs {#faqs}

How do I tell if my deck is ready to be stained? Perform the splash test. Pour a cup of water onto the deck floor. If the water drops bead up on the surface, the old sealer is still active and the deck is not ready to accept stain. If the water absorbs into the wood within 10 seconds, it is ready.

What is the best weather to stain a deck? Apply stain on dry days when temperatures are between 50 and 90 degrees Fahrenheit, and when there is no rain in the forecast for at least 24 hours. Avoid staining in direct hot sunlight, as the stain will dry too quickly, leading to brush marks.