Professional Deck Cleaning in Ontario
Dirt, mould, mildew, and grey weathering rob your deck of its beauty and shorten its lifespan. Our professional cleaning service strips it all away, revealing the clean, healthy wood underneath and preparing your deck for years of enjoyment.
Why Professional Deck Cleaning Matters
Your deck sits outdoors year-round, exposed to everything Ontario throws at it: rain, snow, ice, UV rays, pollen, tree sap, leaf stains, and airborne dirt. Over time, this buildup creates the perfect environment for mould and mildew to take root, turning your once-beautiful deck into a grey, slippery, uninviting surface.
Regular cleaning is not just cosmetic. Mould and mildew actually break down wood fibres, accelerating rot and shortening your deck's lifespan. Dirt and debris trap moisture against the wood surface, which leads to premature finish failure and increased vulnerability to freeze-thaw damage. A clean deck is a deck that lasts longer.
Professional cleaning goes far beyond what a garden hose or rented pressure washer can achieve. We use commercial-grade equipment and deck-specific cleaning solutions that kill mould at the root, dissolve embedded grime, and restore the wood's natural colour — all without damaging the surface. The result is a deck that looks refreshed, feels safe underfoot, and is ready for staining, sealing, or simply enjoying.
Our Deck Cleaning Process
Pre-Clean Inspection
We assess the deck surface, identify the type of soiling (mould, algae, tannin stains, grey weathering), check the wood type, and note any areas that need special attention. This helps us choose the right cleaning solution and pressure settings.
Area Preparation
We move or cover patio furniture, protect adjacent plants and landscaping with drop cloths, and clear debris from between the deck boards. Downspouts and gutters near the deck are checked to ensure they are not contributing to excess moisture.
Cleaning Solution Application
A professional-grade deck cleaner is applied to the entire surface. For mould and mildew, we use an oxygen-based cleaner that kills growth at the root without harsh bleach that can damage wood fibres. The solution is left to dwell for the recommended time to break down embedded grime.
Controlled Pressure Washing
Using commercial equipment with adjustable pressure and the correct fan tip for your wood type, we wash every board, railing, and stair tread. We work methodically with the grain to avoid lap marks and ensure even cleaning. The result is a uniformly clean surface with no streaks or missed spots.
Brightening & Final Rinse
For wood decks, we apply a wood brightener that restores the natural pH balance and brings back the warm tones that cleaning alone may not fully recover. A final low-pressure rinse removes any remaining solution. We clean up the work area and advise on next steps — whether that is staining, sealing, or simply enjoying your refreshed deck.
What We Remove
Mould & Mildew
Black and green growth that thrives in damp, shaded areas. We kill it at the root so it does not grow back immediately after cleaning.
Grey Weathering
The silvery-grey layer caused by UV breakdown of wood fibres. Our process strips it away to reveal the warm, natural wood colour underneath.
Algae & Moss
Green, slippery growth that makes your deck a safety hazard. We remove it thoroughly and treat the surface to inhibit regrowth.
Dirt & Grime
Embedded soil, dust, and foot traffic buildup that dulls your deck's appearance and traps moisture against the wood.
Leaf & Tannin Stains
Dark discolouration left by wet leaves, acorns, and tree sap. Particularly common on decks near maple, oak, and cedar trees.
Old Finish Residue
Peeling or flaking stain and sealer that needs to come off before a fresh coat can be applied. Cleaning is the essential first step before re-finishing.
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Deck Cleaning FAQ
Common questions about our professional deck cleaning services.
We recommend a professional deep clean at least once a year, ideally in spring before you start using the deck for the season. Decks in heavily shaded areas or near trees may benefit from a second cleaning in late fall to remove leaf stains and organic buildup before winter. Regular cleaning extends the life of your stain or sealer and prevents mould from taking hold.
Not when done correctly. The key is using the right pressure, nozzle, and technique for your specific wood type. Consumer-grade pressure washers set too high can gouge soft wood and raise the grain. Our team uses commercial equipment with adjustable pressure and fan tips sized for deck work. We clean thoroughly without damaging the wood surface. Composite decking gets a gentler treatment with lower pressure and appropriate cleaners.
Yes. Our cleaning process combines a professional-grade mould and mildew treatment with controlled pressure washing. The cleaning solution kills mould at the root, not just on the surface, so it does not grow back immediately. For severe mould that has penetrated deep into the wood, we may recommend a brightener treatment after cleaning to fully restore the wood colour.
It depends on the current condition of your existing finish. If your stain or sealer is still performing well (water beads on the surface), cleaning alone may be sufficient. If the finish has worn thin and water soaks into the wood, cleaning is the perfect time to apply a fresh coat of stain or sealer — the clean, open-pored wood will absorb the new finish beautifully. We will advise you during the cleaning on whether re-coating is needed.
Most residential decks take two to four hours to clean, including setup, treatment application, dwell time, pressure washing, and cleanup. Larger decks or heavily soiled surfaces may take longer. The deck should dry for twenty-four to forty-eight hours before foot traffic or furniture is placed back. If staining follows the cleaning, we will schedule that for after the drying period.
Ready to Transform Your Deck?
Get a free, no-obligation quote from our team. We proudly serve Southwestern Ontario with expert deck staining and refinishing.