Pressure Treated vs. Composite vs. Hardwood — Which Deck Material Makes Sense?

The material you choose for your deck is one of the most consequential decisions in the project — and one that most homeowners make without fully understanding how each option actually performs in Pacific Northwest conditions over time. This article covers all three main options honestly — not as a sales pitch for any of them, but as a practical comparison that accounts for the North Shore's climate, the real cost of ownership, and the actual experience of living with each choice over 10, 15, and 20 years.

The North Shore Context

Material selection for a deck on the North Shore isn't the same decision as material selection for a deck in a drier climate. The North Shore receives significantly more rain than most of Metro Vancouver — in some areas, upwards of 2,000mm per year. Temperature cycling through the winter and early spring stresses any material with moisture in it. Many North Shore properties have mature trees that keep decks shaded and damp for extended periods — a condition that accelerates mould and rot in susceptible materials.

Pressure-Treated Lumber

Pressure-treated lumber is the baseline — treated with preservatives that resist rot, fungal decay, and insect damage. Current treatments use alkaline copper quaternary (ACQ) or copper azole (CA) — both more corrosive to standard fasteners than older treatments. This is important: pressure-treated lumber requires stainless steel or hot-dipped galvanized fasteners. Standard zinc-coated fasteners with pressure-treated lumber results in rust staining and fastener failure within a few years.

With proper maintenance — cleaning and resealing every 1–2 years — pressure-treated decking can last 15–20 years. Without maintenance, that number drops considerably. Boards also check and cup over time in response to moisture cycling. The true cost of ownership includes maintenance products and labour, which over a 15-year period can approach the cost of composite.

Best for: Homeowners comfortable with ongoing maintenance, who prefer the natural wood look, or have a tighter upfront budget.

Composite Decking

Composite decking is manufactured from wood fibre and plastic polymers, pressed into decking boards. Most quality composite is capped — wrapped in a solid polymer shell for additional protection against moisture, staining, and UV. It doesn't absorb moisture, doesn't rot, and doesn't require sealing. It resists the mould and mildew that builds up on untreated wood in shaded, damp conditions — which describes many North Shore decks for much of the year.

The limitations are real: lower-end composite without a solid polymer cap can fade noticeably within a few years and show mould staining in shade. This is why product selection matters significantly — the quality range from entry-level to premium is wide. Premium composite — Trex Transcend, Fiberon Sanctuary, Deckorators Voyage — holds colour and resists staining significantly better. Composite also gets hot in direct sun, more so than wood.

Upfront material cost is higher than pressure-treated, but maintenance cost over 15–20 years is minimal. Many premium products carry 25–30 year warranties covering fading and staining. Read the warranty terms carefully.

Best for: Homeowners who want low maintenance, have families with children, are in a shaded or damp location, or are comfortable with a higher upfront investment.

Hardwood Decking

Hardwood decking — primarily ipe, but also cumaru, garapa, and similar tropical hardwoods — are among the hardest, densest timbers available. Ipe has a Janka hardness rating around 3,680 (compared to 1,260 for Douglas fir) and naturally resists rot, insects, and moisture without chemical treatment. When properly installed and periodically oiled, a hardwood deck lasts 30–40 years or more.

Untreated, hardwood will silver-grey to a driftwood tone — a look some homeowners prefer. This is a weathering of the surface only and doesn't affect structural integrity. Oiling every 1–3 years restores the original warm colour. Installation requires pre-drilling all fastener locations — ipe is dense enough that driving screws without pre-drilling will split the wood or snap the screw. Hidden fastener systems produce a cleaner appearance and are standard for quality hardwood installations.

Highest upfront cost of the three options — but over a 30+ year lifespan, a competitive total cost of ownership. Sustainable sourcing — FSC-certified ipe — is worth confirming with your contractor.

Best for: Homeowners who want the best-looking, longest-lasting deck, are willing to pay the upfront premium, and will commit to periodic oiling.

What About Cedar?

Western red cedar appears in many older North Shore decks. It has natural rot resistance, but that resistance varies significantly depending on which part of the log the board came from — heartwood is rot-resistant, sapwood is not. In Pacific Northwest conditions, cedar decking without proper maintenance typically shows significant degradation within 7–10 years. We generally don't recommend cedar for decking on the North Shore when one of the three primary options is available.

What About the Framing?

Regardless of what goes on top, the structural framing of any deck — joists, beams, posts, and ledger — should be pressure-treated lumber. The framing is in contact with or close to the ground, exposed to moisture from above, and needs to resist rot and decay over the life of the deck. Using non-treated framing to save money is a shortcut that affects the structural life of the deck. The decking surface can be replaced when it wears out. The framing is the deck.

Making the Decision

If upfront cost is the primary constraint and you're comfortable with maintenance: pressure-treated lumber. If you want low maintenance and have a family that uses the deck heavily: composite, with a quality product. If you want the best possible result and are willing to invest for longevity: hardwood, properly installed and periodically maintained. If you're not sure — talk to your contractor about the specific conditions of your site, your exposure, and your realistic maintenance commitment.