Cedar versus pressure-treated for a deck in Ottawa weather?

Pressure-treated starts lower on published Ottawa and Ontario builder prices: about about $25 to $65 per square foot installed, while cedar runs about $45 to $80 per square foot installed. Those are wide ranges, and quotes differ on what the rest of the deck involves.

What the materials actually do differently

The USDA Forest Products Laboratory notes that the service lives of naturally durable and preservative-treated woods are quite comparable in above-ground uses such as decking boards. The FPL adds that the most common reason treated decks are removed is splitting and checking, not decay, and the best way to slow that is to keep water beading on the surface rather than soaking in. For posts and components in ground contact, the Forest Products Laboratory recommends preservative-treated wood or the dark heartwood of a naturally durable species.

On finishes, the Forest Products Laboratory's US figures recommend penetrating finishes over film-forming ones on decking. A semitransparent stain lasts about 2 to 3 years on new boards and 3 to 6 years on weathered or saw-textured boards. A water-repellent preservative lasts about 1 to 2 years. Paint and solid stain are rated low suitability for decking. Health Canada notes that residential treated wood may be Alkaline Copper Quaternary or Copper Azole; Chromated Copper Arsenate is no longer available for residential construction. When cutting or sanding treated lumber, wear a dust mask, eye protection, gloves and long sleeves, and never burn it indoors or outdoors.

A few things to ask about and confirm with any quote:

• What species and grade of cedar, or which treated lumber, is being priced
• Whether the quote includes the framing and posts or only the decking boards
• Whether railings and stairs are included, as some published packages exclude them
• What finish, if any, is included, and who applies it

On permits: if your deck needs a building permit, and the City of Ottawa's rules require one for any deck attached to the house with a walking surface more than 600 mm (24 in.) above adjacent grade, the permit application must include scaled drawings showing the framing, foundation, elevations and the deck-to-house connection. If the decking is other than conventional lumber, the City also requires a material testing report, either CCMC or BMEC. Ask the City if you are unsure whether your boards count as conventional lumber. The City lists three inspections: excavation and foundations before backfill, framing at completion of structural framing and guards, and a final inspection. Book each one 48 hours in advance.

Before any digging for footings, whoever is doing the work must submit a locate request through Ontario One Call at least 5 business days before breaking ground. It is free and required by the Ontario Underground Infrastructure Notification System Act, 2012.

Make sure the contract names who applies for the permit and who books each of the three City inspections.