i'm planning to spend more time on our covered deck with upcoming Camp cohorts, so in addition to buying 10 pairs of outdoor slippers it seemed like a good idea to give the deck boards a nice scrub.

first things first, finding the right tool for the job. i've been familiar with pressure washers for a long time, but never used one. i just know that "more PSI" (pounds per sq inch) == more power. but i also know that there is such a thing as too much power.

* if you're cleaning glass or something painted, you can chip it
* if your water source can't produce the required GPM (gallons /minute), your power will be lower

with these concepts in mind i settled on a middle (see: low) tier 1900 PSI electric power washer by Ryobi ($180). it comes with 3 nozzles: "turbo" for highest pressure / smallest area, a soap sprayer for pre washing, and a 15' (angle) nozzle that gets you about 3-7 inches in spray surface width pending distance from the target.

i also thought it would be smart to get one of those circular sprayers that does 12" instead of 4-6, and it was a no-brainer at just $40 extra. but more on that in a second.

benchmarks
here's what we were dealing with before. a lot of green, brown, and red spots. this is a mixture of duck/goose poop, the construction crew's gear, and all the dry clay (thus dust) from before the yard was sodded.

testing it out
after filling up the soap tank with a special concentrate ($15) that mixes 20:1 with water, i began moving the dual-sprayer circle disk thing over the bad spots. and it worked! really well.

but you'll notice a problem... see those clean spiral shapes with green spots on the inside? that happened because the dual sprayer circle attachment thing wasn't getting enough water, thus couldn't create enough pressure. i played with it and found that you can get a really good wash for about 5 seconds, then you need to release the wand trigger and let it "recharge" to hit the advertised PSI.

so i went looking for a water pump that would boost the GPM comming from our hoses. and according to multiple people at Home Depot this is a gimicky product and won't do much for us. i still disagree with them after watching this video but decided to not risk $100s more in gear just to make the pressure washing task go faster.

we then switched to the 15' angle nozzle and did EVERYTHING else with it. which is why this took 9 hours.

downstairs
concrete patio, 8 total "pads" that are approximately 7 by 9 feet each. this was Saturday.

this half of the project was a reminder that even if something looks OK, it may actually be in pretty bad shape. when the entire patio had a tinge of swamp green, you almost couldn't see it. we don't have any clutter so it was "looked" clean.

upstairs deck
we went back to the store to get a new wood deck soap (vs concrete soap) for the upstairs. this half of the project was much faster as scum comes off wood more easily than concrete, however we had new challenges.

namely, wood chipping. half of our upper deck is covered, but the other half is not. that means mere sun and heat exposure was enough to chip a fair amount of our paint, and pressure washing boards with existing paint flaws is tricky. essentially the boards are primed for destruction.

so i lightly washed the first half of the deck from around 12-16 inches away, and i can't really say it looks better but i am sure it's cleaner.

now for the fun part, the covered deck.

here we could hold the nozzle as close as we wanted without damaging the paint. the grime also came off more easily so fewer back/forth waves were needed. 

the only annnoying part about cleaning a deck is moving around heavy furniture.

eventually we got it done.

results
i'm not stoked about spending 3-4 hours on each patio, but i also think we can limit this project to ~once per year. we're mostly doing it to protect the home's value versus aesthetic improvements, but making good impressions for guests is good too.

here's a picture i took this morning of the downstairs patio. the before/after changes aren't as visible upstairs given the shade.

when we do this again i may opt for a more powerful washer, but ultimately it was the right move to try this ourselves instead of paying a professional at least 3-5x as much and not keep any of the gear or expertise.