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Deck cleaning cost calculator

Decks are small in area and slow in labour, which is why per-square-foot pricing runs high and why the call-out floor catches most of them. Wood is soft, the grain lifts, and a job done at driveway pressure looks worse afterwards than it did before. Price the time, not the footage.

Wood deck or fence estimate

Estimated price range

$175 - $240

500-1200 PSI · 40 deg white · 16-24 min on site

Detergent: Sodium percarbonate, neutralising rinse. This is a planning band, not a survey figure: measure the site and price your own labour.

Photograph-style deck boards and railing, weathered grey on one side of the diagonal and bare timber on the other
Wood, low pressure
Cedar boards at a railing post, weathered grey against cleaned cedar.

PSI & nozzle quick reference

0 degRed
Spot jet. Etches most surfaces.4000 PSI
15 degYellow
Stripping bare concrete.4000 PSI
25 degGreen
General concrete and walkways.3500 PSI
40 degWhite
Siding, wood, vehicles.1500 PSI
~65 degBlack
Detergent draw, low pressure.500 PSI

What to measure

Deck area is the walking surface. Railings, balusters and stair risers are separate — they are hand-detail work at maybe a tenth of the speed of open boards. A 16 x 20 ft deck is 320 sq ft of floor and perhaps another 300 linear feet of baluster that will eat an hour on its own.

ElementRate of workNote
Open deck boards40–60 min / 1,000 sq ftWith the grain, always
Railings and balusters15–25 min / 50 lin ftHand detail, quote separately
Stairs3–5 min / treadNosings trap grime
Lattice skirt20–30 min / panel runFragile; lowest pressure on site

Chemistry beats pressure on wood

Sodium percarbonate lifts grey and mildew without the fibre damage hypochlorite causes on bare timber, and it does not need pressure to work. Apply, dwell, agitate with a soft brush where it is stubborn, rinse at 500–1,200 PSI through a 40-degree tip held well back. If the customer wants the wood brightened afterwards, an oxalic-acid brightener is a separate step and a separate line.

Surface damage risk

Wood furs at pressure. Once the soft spring grain is blasted out from between the harder growth rings, the board is permanently fuzzy and the only fix is sanding. Keep the tip moving, keep it back, and never use a zero-degree tip on timber for any reason.

Composite decking is not wood

Composite boards carry a manufacturer’s maximum pressure and an approved cleaner list. Exceed either and the warranty is gone and the surface hazes. Ask for the brand before quoting, and price composite from its own band — it is the dearer one.

Worked example

A 320 sq ft cedar deck, moderate grey, easy access. The square-foot arithmetic gives roughly $112–$192 — under the call-out floor, so the floor is the quote. Add the railing run as its own line and the job prices honestly at a couple of hundred dollars for what is genuinely a half-day of careful work.

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