Is a composite deck worth the extra money in an Ottawa climate?

Whether composite is worth the extra cost depends on how you weigh upfront price against ongoing maintenance, and the honest answer is that the numbers cut both ways.

Published Ottawa and Ontario builder prices put pressure-treated decking at roughly $25 to $65 per square foot installed, and composite at roughly $45 to $95 per square foot installed, with some published packages excluding railings and steps. Those are wide ranges, and where a specific quote lands depends on the size of the deck, its height above grade, the foundation type, the number of stairs, the guard style, whether an old deck needs to come out, and the cost of drawings and the permit. So the gap between a pressure-treated and a composite quote for the same deck can be significant or modest depending on those variables.

On the maintenance side, the USDA Forest Products Laboratory says the most common reason wooden decks get replaced is checking and splitting, not decay, and that keeping water beading on the surface is the best way to slow that down. For a wood deck, penetrating finishes are recommended over film-forming ones, and the FPL's US figures put semitransparent stain at two to three years on new boards and three to six years on weathered boards, with a water-repellent preservative lasting one to two years. Those intervals mean regular upkeep. The FPL also notes that naturally durable and preservative-treated woods perform quite comparably in above-ground uses like decking boards.

For composite and PVC, manufacturers publish 25- and 30-year limited product warranties on composite lines, with fade and stain warranties, and some PVC lines carry a lifetime limited product warranty with a 50-year fade and stain warranty. Read the full warranty document before treating those numbers as a guarantee. For care, follow the manufacturer's guide; we found no neutral cleaning or upkeep interval for composite or PVC.

One Ottawa-specific point worth knowing: if you apply for a building permit and the decking is anything other than conventional lumber, the City of Ottawa requires a material testing report, either a CCMC or BMEC report, as part of the permit application. Your builder or the product supplier can tell you whether the product you are considering has one.

A 2007 US industry survey put wood decks at about 20 years; that figure comes with the caveat that it is a US survey, not an Ottawa measurement, and the FPL notes that a wooden deck can give 40 or more years of service when water is kept beading, which is conditional on that upkeep.

The question is really whether you prefer a lower starting price with a regular finishing schedule, or a higher starting price with the board manufacturer's care routine instead. Neither choice is wrong; it depends on your budget and how much time you want to spend on the deck over the years.

Whichever you choose, get the permit drawings, the issued permit and a written contract that sets out the full scope, the materials specified by product type, and the total price.