Soft Washing Your Deck: Wood vs. Composite — What's the Difference?

Your deck takes a beating from Ontario's weather — hot summers, cold winters, spring rain, and fall leaves. Whether you have a traditional wood deck or a modern composite, keeping it clean is essential for longevity and appearance. But the cleaning method differs significantly between materials.

Cleaning Wood Decks

Wood decks (pressure-treated pine, cedar, redwood) require careful cleaning to remove mold, mildew, and grey weathering without raising grain or causing damage. A wood-safe deck cleaner applied with a soft brush or low-pressure washer dissolves biological growth and lifts surface grime. After cleaning, allow to dry completely (48–72 hours) before applying deck stain or sealer. Skipping the clean before staining causes stain to seal in contaminants and fail prematurely.

Cleaning Composite Decks

Composite decks (Trex, TimberTech, Fiberon) are often marketed as "maintenance-free" — but they still require cleaning. Composite materials can harbour mold and mildew between boards and on surfaces, especially in shaded areas. Most manufacturers recommend low-pressure washing with composite-approved cleaners only. Many composite warranties are voided by high-pressure washing. Always check your deck manufacturer's cleaning guidelines before applying any product.

Products to Avoid on Decks

Never use chlorine bleach on composite decks — it can bleach the colour unevenly and damage the material. Avoid petroleum-based cleaners, abrasive scrubbers, or pressure above 1,000 PSI. On wood decks, alkaline cleaners can raise grain and damage wood fibres. The right product matched to the material makes the difference between a clean deck and a damaged one.

What to Do After Deck Cleaning

Wood decks: apply a penetrating wood stain or deck sealer within a week of cleaning while the surface is open and receptive. Composite decks: apply a composite-specific protector if desired, but many composites don't require it. Inspect boards for any loose screws, popped fasteners, or damaged boards while the deck is clean — it's the best time to address minor repairs.

Annual Deck Maintenance Schedule

Clean your deck at least once a year — spring is ideal to remove winter debris and prepare for outdoor season. Restain or reseal wood decks every 2–3 years. Book a professional deck cleaning with D&D Home Services for the right approach to your deck type in Kitchener-Waterloo.

D&D Home Services Team Exterior Cleaning Experts — Kitchener-Waterloo

With years of hands-on experience cleaning hundreds of homes across Kitchener, Waterloo, Cambridge, and Guelph, our team shares practical, locally-relevant advice you can trust.