Step-by-Step Process from a Local Contractor
I often see moss growing between deck boards, and honestly, I think it looks beautiful. Like nature sneaking its way in. But the truth is, moss is harmful to your deck. It holds moisture deep in the seams, which accelerates wood rot and shortens the life of your wood. That’s why careful preparation before pressure washing is so important.
As a Seattle-based deck restoration contractor, I take this process seriously. Here’s how I typically prepare a deck for washing to get the best results without causing damage.
1. Taping Off and Protecting the Area
Before anything else, we tape off the perimeter of the deck and cover surrounding areas like siding, doors, vents, outlets, and plants. This protects your home and landscaping from overspray, chemical exposure, and high water pressure.
2. Cleaning Out the Gaps Between Boards
Next, we manually clean the gaps between deck boards using hand tools. This step removes built-up debris like dirt, moss, twigs, and small rocks that get stuck in tight spots. Clearing these gaps allows the cleaner and rinse water to reach the wood surface more effectively.
3. Applying a Wood-Safe Cleaning Solution
Once the deck is cleared, we apply a biodegradable, wood-safe deck cleaning solution. This helps break down grime, mold, mildew, and any organic growth. We let it sit for 10–15 minutes to give it time to work deep into the surface.
4. Brushing the Deck Surface
To help lift any remaining dirt, we scrub the deck using a stiff-bristled deck brush. This step is critical, especially on older decks or those with heavy staining. Brushing provides a deeper clean and reduces the need for excessive pressure during rinsing.
5. Rinsing with a Pressure Washer (the Right Way)
Finally, we rinse the deck with a pressure washer set to a safe PSI. We always spray with the wood grain and keep the nozzle at the correct distance. High pressure on wet wood can cause splintering or damage soft spots. Our goal is to gently rinse, not blast the surface.
Why Proper Deck Washing Preparation Matters
Incorrect use of a pressure washer on wood decks can cause permanent damage. Wet wood is vulnerable, and too much pressure or the wrong technique can lead to gouging and fraying. That’s why professional deck cleaning in Seattle requires patience, the right tools, and proper preparation.
If your deck has moss, dirt, or signs of aging, don’t risk damaging it with DIY power washing. Contact us for expert deck washing services and let us restore your deck the right way.