Ontario winters destroy bad decks. Twenty freeze-thaw cycles per year, plus salt tracked from the driveway, plus snow load — your deck material choice matters more here than in Vancouver or California.
Three serious options. Here's the honest tradeoff at year 10.
Pressure-Treated Pine (PT) — Cheapest, Most Work
Cost: $30-$45 per sq ft installed Year-10 appearance: Grey, splintering, some board warping Annual maintenance: Power-wash every spring (~2 hours) + stain or seal every 2-3 years (~4 hours)
Pressure-treated lumber is what 70% of GTA decks are built with. It's structurally fine for 20+ years if you build it right (proper joist spacing, hidden fasteners or screwed-down to spec, ground contact-rated for posts).
Where it falls apart: the visual. PT wood greys within 18 months and splinters as it dries. If you don't stain it within year 1, you've committed to "natural grey rustic deck" forever. If you do stain it, you're now signed up for annual upkeep.
Best for: Budget builds, decks under 200 sq ft, decks you don't sit on much, or projects where you'll likely renovate again in 10 years.
Cedar — Best Looking, Annual Effort Required
Cost: $45-$70 per sq ft installed Year-10 appearance: Beautiful if maintained; greys-and-warps if not Annual maintenance: Oil or stain every spring (~6 hours) to keep the red tones
Western Red Cedar is the best-looking option year 1. The red-brown tones, the smell, the natural rot resistance — there's a reason high-end Toronto neighbourhoods like The Annex and Old Oakville still favor cedar for visible decks.
The catch: cedar greys faster than people expect. Without annual oiling, your year-3 cedar deck looks identical to a year-3 PT deck — except you paid 50% more for it.
Best for: Homeowners willing to oil annually, smaller deck footprints where labour is manageable, primary-view decks where appearance matters.
Composite (Trex, TimberTech, AZEK) — Most Expensive, Zero Maintenance
Cost: $65-$110 per sq ft installed (boards alone are $5-$8/linear ft retail) Year-10 appearance: Same as day 1 if you bought a current-gen product (post-2018) Annual maintenance: Rinse with water; sweep snow off (~30 min total per year)
Composite decking changed dramatically around 2018. Early composites (Trex Gen 1, etc.) faded badly and developed mold. Current-gen capped composites (Trex Transcend, TimberTech AZEK, Fiberon) have a polymer cap that resists fading, staining, and mold for 25+ years.
The honest math on composite vs PT over 25 years: - PT: $30/sq ft × 200 sq ft = $6,000 + 25 years × 6 hours stain/$80 stain = ~$1,600 in maintenance + your 150 hours of labour - Composite: $80/sq ft × 200 sq ft = $16,000 + nearly $0 maintenance
If your time costs anything, composite breaks even around year 8-10.
Best for: Larger decks, families that actually use the deck (vs decorative-only), homeowners who'd rather spend Saturday relaxing than staining.
What about aluminum decking?
A small slice of the market (~3%) installs aluminum decking — DuxxBak, AridDek. It's fireproof, lifetime warranty, ZERO maintenance. Cost is $130+ per sq ft installed though. We've built about a dozen aluminum decks in Vaughan and Mississauga over the last 5 years — typically for high-end clients in fire-restricted areas (closer to ravine systems) or for rooftop decks where weight matters.
The hidden cost everyone forgets
Permit + structural. Decks over 24" off grade need a permit in Ontario. Decks attached to the house need a ledger board flashing detail to prevent water intrusion behind the siding (this is what causes 90% of deck-related home damage). Permit + drawings add $400-$800 to any deck regardless of material.
Skipping the permit to save $500 has cost homeowners we know $40,000+ when their unpermitted ledger leaked into the house wall.
Quick decision matrix
- Under 200 sq ft, budget conscious, don't mind maintenance: PT - Under 200 sq ft, primary view, willing to oil: Cedar - Over 300 sq ft, family deck, want to enjoy weekends: Composite
Want us to scope yours? Use the quote calculator below — 3 questions, real GTA pricing for deck building emailed in under a minute.