How to Maintain Your Deck: A Seasonal Guide for Canadian Homeowners

Key Takeaways:

• Wood decks need spring cleaning + annual staining — budget $200–$400/year
• Composite and PVC decks need only soap-and-water cleaning twice a year
• Spring is the critical inspection season — catch damage from winter before it gets worse
• The best time to stain is late spring or early fall (10–25°C, no rain for 48 hours)
• Ignoring maintenance on wood decks cuts their lifespan from 20 years to under 8

Spring: The Most Important Season

Spring is when winter damage reveals itself. After months of freeze-thaw, snow load, and ice, your deck needs a thorough inspection and cleaning before the outdoor season begins.

Spring Inspection Checklist

Check every item — catching problems early prevents expensive repairs:

• Board condition: look for cracks, splits, warping, soft spots (soft = rot)
• Fastener check: are any screws popped up? Nail heads raised? Boards loose?
• Structural integrity: push on railings — any wobble means loose connections
• Stair safety: treads secure? Handrail tight? Anti-slip surfaces intact?
• Ledger board: check the connection where the deck meets the house — water stains or soft wood here is a critical structural concern
• Footings: any posts leaning? Frost heave can shift footings over winter
• Under-deck: check skirting for animal damage, debris buildup, drainage issues

Spring Cleaning by Material

Material	Cleaning Method	Time	Cost
PT Wood	Power wash (1,500–2,000 PSI) + brightener	3–4 hrs	$50–$100
Cedar	Gentle wash (1,200 PSI max) + wood cleaner	2–3 hrs	$40–$80
Composite	Soap + water, soft brush, garden hose	1–2 hrs	$10–$20
PVC	Soap + water, soft brush	1–2 hrs	$10–$20
Aluminum	Rinse with garden hose	30 min	$0

Warning: never power wash composite above 1,500 PSI — high pressure can damage the polymer cap. Never use a zero-degree nozzle on any deck material.

Summer: Enjoy and Protect

Summer maintenance is minimal if spring cleaning and staining were done properly.

Weekly Tasks (5 minutes)

• Sweep off debris — leaves and food trap moisture against the surface
• Move planters periodically — constant moisture under pots causes discolouration

Monthly Tasks (30 minutes)

• Hose off the deck to remove pollen, dust, and bird droppings
• Check that lighting fixtures are working
• Tighten any loose railing connections

Summer Staining Window

If you didn't stain in spring, September is your second-best window — temperatures between 10–25°C, lower humidity than summer, and 48+ hours without rain. Oil-based stains need 24–48 hours of dry weather to cure; water-based need 4–6 hours.

Fall: Prepare for Winter

Fall preparation determines how well your deck survives winter.

Pre-Winter Checklist

1. Final cleaning — sweep all leaves. Wet leaves left on wood create dark stains and accelerate rot
2. Clear drainage — ensure gaps between boards are clear for water flow
3. Check sealant — if water doesn't bead on wood surfaces, apply a quick coat of sealer before freeze
4. Remove furniture or cover with breathable covers (not tarps — they trap moisture)
5. Retract awnings and remove fabric canopy covers
6. Test stair safety — add anti-slip treads before the first freeze
7. Store solar post caps indoors if they aren't rated for -20°C

Winter: Minimal but Important

Snow Removal

• Use a plastic shovel — never metal blades on any deck surface
• Shovel with the grain on wood decks to avoid gouging
• Composite manufacturers generally say snow removal is optional — but heavy accumulation exceeding your deck's snow load rating should be addressed
• Clear stairs first — they're the safety priority

Ice Management

• Never use rock salt (sodium chloride) on any deck — damages wood finishes and can stain composite
• Safe alternatives: sand, kitty litter, or calcium magnesium acetate (CMA)
• For persistent ice near the house, check that downspouts aren't directing water onto the deck

Annual Maintenance Cost Summary

Material	Annual Maintenance	10-Year Total	Effort Level
PT Wood	$200–$400	$2,000–$4,000	High (6–8 hrs)
Cedar	$150–$350	$1,500–$3,500	Medium (4–6 hrs)
Composite	$20–$50	$200–$500	Low (2 hrs)
PVC	$10–$30	$100–$300	Very low (1 hr)
Aluminum	$0–$10	$0–$100	None (30 min rinse)

Frequently Asked Questions

How do I know when my deck needs re-staining?

Splash water on the surface. If it soaks in within 10 seconds, the stain has worn through — time to re-apply. If it beads up, the existing stain is still protecting the wood.

Can I pressure wash composite decking?

Yes, but keep pressure below 1,500 PSI and use a fan nozzle (not zero-degree). Hold the nozzle at least 12 inches from the surface. Higher pressure damages the polymer cap.

What causes black spots on my composite deck?

Usually mould or mildew growing on surface debris (pollen, food residue) — not on the composite itself. Clean with a composite deck cleaner and a soft brush. Prevent it by keeping the surface clean and ensuring good air circulation under the deck.

Should I cover my deck furniture in winter?

Use breathable fabric covers — not plastic tarps. Tarps trap moisture underneath, promoting mould growth on both the furniture and the deck surface.