Deck wash suggestion?

Guy called for house wash and wants the “deck cleaned up” too… What would be your approach on cleaning it?

I add jomax into my SH and DS it, let it set for about 5 to 10 mins then I use 25 degree green tip. On a deck that size I adjust psi down to 2000-2500 and use my surface cleaner, works great for me.

In general, that much pressure and/or using a surface cleaner is usually frowned on for deck work, because it can cause unnecessary damage to the wood. If you are very careful about not making lap marks, you might be able to pull it off… but again, the general opinion is to let the chemicals do most of the work.

Generally with a deck like that (no stain and light mold/mildew), the recommended advice is to either treat with a light HW mix, or Sodium Percarbonate. Percarbonate is safer on plants.

HW mix: Prewet, then direct apply 1.5% HW mix, dwell, then rinse with 600-800 (maybe up to 1000) PSI for cedar, and up to 1000-1500 PSI yellow pine. 40 degree fan tip is a common size. Some people follow with oxalic, 4-8 oz per gallon water, DS.

Sodium percarbonate: Prewet, 6-8oz per gallon water direct application, dwell, rinse as above. Most people follow percarbonate with oxalic acid.

Sodium percarbonate isn’t as effective as Sodium Hypochlorite at killing mold/mildew. One experienced wood veteran (rpetry) says that if mold/mildew is present in moderate quantity, they will sometimes first do a bleach cleaning, then percarb and oxalic. If the mold/mildew is light, the percarbonate and rinse may take care of it.

*I’m not an expert. The information above was obtained by reading hundreds of posts by veteran washers. There is no 100% agreed method, and mix ratios vary between people. Use the information as a reference, and practice to determine what works best for you.


Basically all the advice in the post should be avoided. All of it.

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And you haven’t had to file an insurance claim?

Surface cleaner on a deck sounds like an awful idea. And jomax? Just add more bleach and save some money if you’re going to dry out and fur the mess out of the wood. But don’t actually do that…

@Newimage someone posted a video about deck wood restoration. Do some searching because it’s good stuff. I think it’s safe to say that most folks here use their housewash mix which is super low concentration of SH if they use SH at all. Then they use a neautralizer or a brightener like oxalic.

You know the fuzzy things you get when you pressure wash a deck. You’re not supposed to get those. That’s damaged wood. There’s a better way and a handful of people here are doing it the right way. Take some time to search and check out the posts with pics.

One guy was even testing stuff on old fence panels to get the results he wanted. There’s good info around.

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That was me. :grin:


Knock on wood I haven’t splintered or messed up any wood decks so far. I thought the same thing about surface cleaner on wood decks and I seen a company using one on a lot boat docks down on the lake close to my house, so I pulled over and talked with them about it for a while and watch them work. I went home and tried it out on my pool deck and my two decks around my house. Started at 1000psi and moved up lil at a time till got to a smooth working psi. No mark, splintered or anything but it will also depend on what shape the wood is in as well. Maybe iv just been lucky I guess.

That was awesome. Lol

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All decks are different. Some of them are tough as nails and others will explode in your face if you are a bit overzealous. I’ve had pretty good success using a my house wash mix and letting it sit for a goodly stretch of time then pressure washing it with a 45° tip backed off a few inches. I’ve even used a turbo nozzle backed off and it worked great (note: I do not recommend you do this. Turbo nozzles and wood surfaces are a great way to get crazy scar marks.) but get a feel for the planks and see how ingrained that dirt is. At the end of the day just make sure you’re practicing good form like doing one plank at a time in one sweep and not stopping in the middle.

I’ve achieved the aforementioned wood fluffies before and agree that’s probably not the greatest end result— but just look at that new color!!! Haha you can always sand it when it dries.