How to Clean Wood Deck
What You'll Need
- Per product directions
- Bucket
- 1
- 1
- Per project size
Step-by-Step Method
Remove all furniture, planters, and mats. Sweep the entire deck to remove loose debris, leaves, and dirt. Clear debris from between deck boards with a putty knife.
Mix oxygen bleach (sodium percarbonate) with warm water per product directions. Oxygen bleach is safer for wood, plants, and the environment than chlorine bleach.
Apply the solution to the entire deck using a pump sprayer or by pouring from a bucket. Let it soak for 15-20 minutes. Do not let it dry on the surface.
Scrub the deck with a stiff brush, working with the wood grain. Pay extra attention to high-traffic areas, shaded spots (more algae), and areas near railings.
Rinse the entire deck with a garden hose using a strong spray nozzle. Work from the house outward so dirty water flows away from the structure.
Let the deck dry completely (24-48 hours). Assess whether it needs sealing or staining. A water droplet test tells you: if water soaks in, the deck needs sealing. If it beads, the existing seal is intact.
- Do not use a pressure washer above 1500 PSI on softwood decks (cedar, pine). High pressure damages wood fibers and creates a rough surface.
- Do not use chlorine bleach on wood (destroys lignin, the natural binding agent in wood)
- Do not seal or stain a wet deck (sealer will not adhere and traps moisture)
- A pressure washer CAN be used at low pressure (under 1500 PSI) with a wide fan tip, held 12+ inches from the surface. But a brush and hose give you more control and less risk of damage.
- Trim back vegetation that touches or shades the deck. Air circulation and sunlight are the best natural mold preventers.
- Composite decking (Trex, TimberTech) cleans with soapy water only. Do not use oxygen bleach on composite.
Frequently Asked Questions
Every 1-3 years depending on sun exposure, foot traffic, and the type of sealer or stain. The water droplet test is definitive: pour water on the deck. If it soaks in within 10 minutes, it is time to reseal. If it beads up, you are still protected.
Sources & Methodology
Oxygen bleach (sodium percarbonate) releases hydrogen peroxide when dissolved in water, providing antimicrobial and stain-removing action without the fiber damage caused by chlorine bleach. Deck sealing timelines from hardwood lumber industry guidelines.
Last reviewed: March 20, 2026