Underside of a taller deck

How do y’all go about cleaning tall decks? Customer has a synthetic walnut deck he wants the underside cleaned and stained to match the top. Support beams and posts are natural, no treatment, or possibly pressure treated, not too dirty but requires cleaning before staining. My best hope is that with it being so young that my chemicals do the job, sodium percarbonate or sh followed by oxalic brightener and after it’s dry, stain.

But if it were really dirty, or if the stains don’t come out I imagine 40° tip rinsing… But this deck is close to 12-15ft tall. Do y’all just get a sturdy A-frame to bust out the pressure washer rinse? What if the deck is 25ft tall, do you build scaffolding at that point? My pressure washer is 6gpm 4500psi and I nearly get knocked over standing on the ground let alone reaching high places.

Let me know your favorite 6ft step ladder safe for pressure washing or any other advice considering future tall pressure rinsing. Very curious.

Got a few photos of this job here but like I said, all info is welcome for future reference.

Downstream some sodium hydroxide, rinse. A 6ft wand is all you need if low pressure didn’t get. No need for a ladder

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How are you going to stain that?
You’ll be working overhead and no option to spray.


Idk lol I could fall back on the painter if need be. Maybe just old school ladder and brush? I’ve seen some deck sealing wands that have a square sponge/edger tip that you actually load with sealer like a straw and push it out as you go. That might do it. :man_shrugging:

Glad I have a huge drop-cloth, I could see this getting messy.

Just realize it will take a long time and your arms are going to get tired quick. Charge accordingly.


That deck is sitting on concrete. Oil stain will go through a canvas drop cloth. Pre wet concrete with soap and water, put plastic down. Some talented people here don’t use the plastic, they just keep it wet and rinse, but I don’t take those chances because I work solo and things never go smoothly for me. Prepare to clean the siding if you don’t put up plastic.


Good notes! Thanks y’all

Customer has also has had a gnarly staining nightmare on his concrete. The dude since has quit power washing. I wonder what he did that made this happen. Again, only 18months-ish old

Holy crap! Someone came in and etched and totally ruined his concrete and just left it like that? That stain is nothing compared to what his pressure washer did to it

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Too me that’s a huge pain. I use canvas drop cloths all the time and don’t have issues with the stain going through. If I’m concerned about it, I’ll put down another drop cloth on top of the first one.

I’ve tried the whole “soap and water” a few times. It takes more time in the majority of the situations I’ve used it and has the potential to make a mess.

I also use plastic to cover the house all around where I’m working…if I’m spraying… especially oil-based stains. I’ve noticed that most of the vids where they’re not using plastic, they’re spraying fences and are in open areas.

Yeah… like $26k worth of concrete washed and “stained” he says it looks a heck of a lot better now than it did when it all happened. I wonder if it even had a chance to cure before he attacked it with the wash :person_facepalming:

Man that is so destroyed its impressive. I feel bad for the home owner but you do get what you pay for most of the time. As far as the deck be careful and put down a drop cloth or two. Don’t want to give the guy flash backs to wwe driveway destruction and he’ll be more appreciative than most when theres no damage

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There’s a whole lot of easier money with a lot less time investment than that job. You can’t charge enough for the PITA it’s going to be. I did one real similar, except I had to stain the posts which were sitting on concrete, so had to tape them off too, a long time ago… NEVER again.


Lol I have to do it, he’s a friend of mine. I just pray I come prepared enough and I can finish the staining itself in one day. He didn’t even ask about his concrete, think that one still burns from the last experience lol

Not much of a friend if he’s asking you to do that, lol. I wouldn’t wish that job on anyone. Bring plenty of plastic, and not the real light weight stuff either, it blows around too much and is a pain to tape. It’ll take you almost as much time to prep as it does to stain.


Your a pro, this guy obviously didn’t know what he was getting into. You probably have large heavyweight canvas cloths because you know the el cheapos are worthless. Your experience has probably taught you to double them up (half the tarp used). I imagine when he said he had a large tap, he was going to lay his one tarp down and move it around, probably thin canvas, and stain drips would likely go right through it.

Although I agree that the water/soap/plastic is a large PITA, I still do it on every sidewalk coming off a deck. My last one my helper (my kid) kicked a bucket and the stain went right through the double layered tarp. Had plastic underneath so I was saved. Kid learned one more thing about staining a deck, other than the dislike of work on a hot sunny day.


Update: yes this is a complete PITA lol

Rented scaffolding for $50 on Friday so I could work Saturday without paying a second day. I’m definitely going to have to do this again the next clear Friday/Saturday. So far him and his wife are very happy and understanding that it’s taking forever to do. They appreciate that it’s getting done with care.

No drop cloths or masking of any kind. The concrete has a sealer on it and I’m getting by catching drips as they fall and using mean green degreaser and a dry lint free rag to clean little drips. 1 regular size natural purdy brush and 1 large valspar china brush (couldn’t find a big natural) but I actually like the china blend. Have no idea why it’s called china but whatever, it says it’s good for oil based stain. I’ll go get an angled little brush for tight corners before the next go.
Tarp under my supplies in the grass.

Wish me luck, it’s 95° (little hot for stain but it’s shaded so I figured long strokes and full saturation I’ll be fine.)

Under the steps down low sucked ■■■ but I think 2 more solid days and I’ll finish :crossed_fingers:

Someone who paints regularly could probably knock this out in just 2 days but I’m new and slow, doing my best.

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Your a good friend . Nice job, and in the 90 plus heat to boot.

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That concrete can be ‘fixed’ using chems and a surface cleaner.

Really? Why?

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