The most common question we get during deck consultations is whether to use composite decking or pressure-treated lumber. Both are legitimate choices and both have real trade-offs. Here is how we explain the comparison to clients, based on decks we have built across Toronto, Oakville, and Burlington.

Upfront cost

Pressure-treated lumber is less expensive to purchase. For a 300 sq ft deck, the decking boards alone might cost $1,800 to $2,400 in pressure-treated lumber versus $4,500 to $6,500 for a composite product like Trex Transcend or Fiberon Paramount. The structural framing (joists, beams, posts) is pressure-treated regardless of which decking surface you choose, so that cost is the same either way. On a total installed basis, a composite deck typically costs 40 to 60 percent more than a pressure-treated deck of the same size.

Maintenance over time

Pressure-treated lumber requires annual or biannual maintenance: cleaning, sanding any raised grain, and applying a penetrating sealer or stain. If this is skipped, the wood will grey, check (develop surface cracks), and eventually splinter. A well-maintained pressure-treated deck can last 15 to 20 years. Composite decking requires cleaning once or twice a year with soap and water or a composite-specific cleaner. It does not need staining or sealing. Most composite products carry a 25 to 30 year manufacturer warranty against fading and staining.

Performance in Toronto winters

Both materials handle Toronto's freeze-thaw cycle reasonably well when installed correctly. The critical factor is not the decking surface but the structural framing and footings. Footings that do not reach below frost depth (48 inches in the GTA) will heave and shift the deck regardless of what is on top. We have seen composite decks on shallow footings fail in three years and pressure-treated decks on proper footings last twenty. The decking material is secondary to the structural foundation.

Which one to choose

If you plan to stay in the house for more than ten years and want to minimize ongoing maintenance, composite is worth the higher upfront cost. If you are comfortable with annual maintenance and want to keep the initial budget lower, pressure-treated is a reasonable choice. We do not push one over the other. We build both and we build them the same way structurally.

The right choice depends on your budget, your maintenance tolerance, and how long you plan to stay in the house. If you want to talk through the specifics of your backyard and get a written quote for both options, reach us to schedule an estimate.