When should a new Ottawa deck get its first stain?

We found no government or standards-body source that sets when a new deck should get its first finish, so follow the finish manufacturer's label and ask your builder what the product they use says. What the USDA Forest Products Laboratory does give is how finishes behave on decking once they are on.

The FPL's finish table gives these re-coat intervals for decking: tinted deck finishes last 1 to 2 years on new smooth-sawn boards and 2 to 3 years on weathered or saw-textured boards; semitransparent stain lasts 2 to 3 years on new boards and 3 to 6 years on weathered ones. A water-repellent preservative lasts only 1 to 2 years. Those are US figures, and the source says expected life depends on climate and exposure. The FPL recommends penetrating finishes for decks because film-forming finishes such as paint and solid stain are very difficult to maintain on a walking surface, and penetrating finishes have to be refreshed every few years.

A few points worth keeping in mind:

• The FPL notes that copper-based waterborne treatments may keep a brown colour for about 2 years.
• Its core advice is to keep water beading on the surface instead of soaking in, and the FPL says wooden decks are most commonly replaced because of checking and splitting, not decay.
• For older decks built before 2004, Health Canada notes they may contain CCA-treated lumber; if so, consider applying a sealant every year using an oil- or water-based stain, and avoid film-forming products.

If your deck used composite or PVC decking rather than wood, the finishing question is different: follow the manufacturer's care guide; we found no neutral cleaning or upkeep interval for those materials.

If you hire the finishing out, ask which product and preparation the quote covers.