How much does it cost to clean and seal a deck?

Short answer

Cleaning and resealing a deck yourself costs $50 to $150, which is the deck cleaner and the stain or sealer, and takes 240 to 480 minutes spread over a couple of days for drying. A deck contractor charges $500 to $1,500 to do the same. The cleaning comes once a year and the sealing every 1 to 3 years, so most years the cost is a jug of cleaner and an afternoon. The pro price is for the sealing years, and it's worth considering on a big deck or one with a lot of railing.

Cost breakdown

The DIY column is the cleaner and the stain or sealer, applied with a deck brush and a roller or a pump sprayer you likely own. A garden hose does the rinsing, and a pressure washer is optional. The pro column is a crew that cleans, lets the wood dry, sands the rough spots and applies the finish.

What drives the cost

• The deck's size. Both the finish and the labor scale with square footage, and railings and stairs add a surprising amount, since every baluster is brushed by hand.
• The finish. A clear sealer is the low end. A semi-transparent stain costs more and lasts longer, and a solid stain is the most expensive and the hardest to strip later.
• The condition. A deck that's been cleaned every year takes a cleaner and a rinse. A gray, neglected deck needs a stripper, a brightener and sanding before any finish will stick, and that's where the pro price climbs.
• The wood. A pressure-treated deck is the baseline. Cedar, redwood or a hardwood deck takes a finish made for it, which costs more.
• Composite decking. It's cleaned once a year and it doesn't need sealing, so the whole sealing cost disappears.

DIY vs. pro

The yearly cleaning is yours, and it's cheap: how often to clean and seal a deck is a clean once a year and a reseal every 1 to 3 years, and the cleaning is a jug of deck cleaner, a stiff brush and a hose. Skipping it is what turns a sealing year into a stripping year.

The sealing is a reasonable DIY job on a deck you can walk around in a few minutes, and the money favors it at $50 to $150 against $500 to $1,500. Pay the pro for a large or multi-level deck, for a deck that needs stripping and sanding, or when the railings would take you a weekend on their own. Either way, the finish only lasts if the wood is clean and fully dry when it goes on, so the prep is most of the job.

FAQ

How much does it cost to stain a deck?

$500 to $1,500 from a contractor, depending on the size, the condition and the finish. The stain alone is $50 to $150 for a DIY job.

Is it cheaper to seal a deck myself?

Yes, by a wide margin. The cleaner and sealer cost $50 to $150, and the job takes a couple of days with drying time.

How often does a deck need sealing?

Every 1 to 3 years, when water stops beading on the boards. Clean it once a year regardless.

Does a composite deck need sealing?

No. Clean it once a year with a deck cleaner made for composite and skip the sealer.