Deck and fence staining

A deck in Ottawa takes ultraviolet all summer, forty-odd freeze-thaw cycles all winter, and salt or grit tracked across it for five months. Left uncoated, pressure-treated softwood goes grey in two seasons and starts checking in three or four. Staining is maintenance rather than decoration.

Step one: work out what is on there now, and what the wood is. A penetrating oil stain, a semi-transparent, a solid colour stain and a film-forming deck paint all behave differently and, critically, are not always compatible with each other. A solid stain over a failing oil will peel. New pressure-treated lumber is another case entirely: it arrives wet with preservative and usually needs several months of drying before it will accept a coating, which for a deck built in June often means staining the following spring.

Step two: clean and strip. Grey wood is ultraviolet-damaged surface fibre and it has to come off or the stain sits on a layer that will detach. A deck cleaner or a percarbonate wash lifts it, followed by a wood brightener, which is usually an oxalic acid solution that neutralises the cleaner and restores the pH so the stain absorbs evenly. If there is a failing film-forming product on there, it has to be stripped or sanded off entirely, which is the single biggest variable in a deck quote.

Step three: repairs and sanding. Loose boards refastened, popped screws reset, splintered boards replaced, protruding nails countersunk. A light sand takes down raised grain from the washing and smooths the surface. Railings and the tops of posts get particular attention because they are where the water sits.

Step four: coating. Two thin coats of a penetrating stain, applied wet on wet or with the manufacturer's stated interval, brushed or pad-applied into the grain rather than flooded on. Overapplication is the classic deck failure: stain that cannot penetrate sits on the surface, stays tacky, and peels. The end grain at the cut ends of boards drinks far more than the faces and should be given extra.

How long it takes. A typical 30 square metre (320 square foot) deck is two to four days including drying time between the wash and the coating. A deck that has to be stripped of an old solid stain can take twice that. Fences are quicker per square metre but there is usually a lot more of them: a 30 metre run of six-foot board fence, both sides, is commonly two to three days.

What it costs in Ottawa in 2026. Indicative. Cleaning, brightening and two coats of semi-transparent stain on a straightforward deck runs roughly $20 to $40 per square metre of deck surface ($2 to $4 per square foot), with railings and stairs adding meaningfully because they are labour-dense. An average 30 square metre deck with railings commonly lands between $900 and $2,200. Stripping a failed solid stain can add $800 to $2,500 on its own. Fencing is often quoted per linear metre, typically $25 to $55 per metre for both sides of a six-foot board fence.

Timing, and why Ottawa is tight. Stains generally need surface temperatures above roughly 10 degrees Celsius, no rain for 24 to 48 hours after application, and no direct hot sun during application, because a surface at 40 degrees flashes the carrier off before the stain can penetrate. That combination rules out a lot of days. In practice the good windows here are late May into June, and again in September, which is why deck crews are booked solid in both. An October deck job is a gamble: the wood may not dry enough between the wash and the coat, and an overnight frost on a fresh oil stain is a poor outcome.

What makes an Ottawa deck different. Snow load is the honest answer. A deck here carries snow for four or five months, which keeps the surface wet at the freezing point for long stretches rather than shedding water the way a deck in a milder climate does. That sustained wet-freeze is why horizontal surfaces here need recoating every two to three years while the vertical faces of the same railing can go five. It is also why penetrating stains generally outperform film-forming products on Ottawa deck boards: when a film fails under ice it peels in sheets, while a penetrating stain simply wears thin and can be recoated without stripping.

Who should do the work. No licence exists in Ontario for painting or staining (Skilled Trades Ontario, Painter and Decorator (Commercial and Residential), trade code 404C). The credentials to ask for are liability insurance and WSIB coverage (WSIB, Expanded Compulsory Coverage in Construction). What actually separates crews is method: whether they brighten after cleaning, whether they use a moisture meter before coating, and whether they will tell you your new deck needs to wait until next year rather than take your money now.

What to ask before you hire. What is currently on my deck, and is your product compatible with it. Are you cleaning only, or cleaning and brightening. Will you check moisture content before coating. Penetrating or film-forming, and why for my deck. How many coats. Is the railing and stair work included in the square metre price or extra. What is the recoat interval you expect, and what does your warranty actually cover. If it rains two days after you finish, who comes back.