I have a question about cleaning the painted outside facade/stucco of my house (I'm not asking for a specific product-recommendation).

Which commonly available detergents/chemicals are suitable for cleaning it (since it became a bit dirty over the last 20 years) and which detergents/compounds should be specifically avoided because they could be too abrasive/aggresive towards the lime in the plastering or the stucco-paint on top of it?

I'd also be interested in some physical methods from ppl who have elaborate experience with cleaning stucco/facades.

I tried finding some answers via the search-bar here but only found those two sort of unrelated questions (1 & 2).

  • 1
    Whatever you decide to use, test it on a hidden bit first.
    – Solar Mike
    Jul 6, 2021 at 12:45
  • @SolarMike Good idea, I will be using a small patch on the backside of my house and not just test various chemicals/detergents but also various mechanical approaches (various brushes, high pressure cleaners such as Kärcher etc..)
    – iLuvLogix
    Jul 6, 2021 at 12:51
  • Well, don't use CLR nor Lime-Away for starters. Most Google searches say to use some dish soap like Dawn with water or a 50:50 bleach+water mix. Is there a reason you didn't come to either of these conclusions? If you're using a pressure washer then just be careful to not strip your stucco. You'd be amazed at what a bucket of water and sponge or soft bristle brush will remove.
    – MonkeyZeus
    Jul 6, 2021 at 14:31
  • @MonkeyZeus 'Is there a reason you didn't come to either of these conclusions?' -> Soap and spong is obvious but I'd like to get some advice from ppl who might have elaborate experience on this and also know what should be avoided. But if you like you can expand your comment to answer if you can add some reasoning to why some solvents are suitable and which are not and why ;)
    – iLuvLogix
    Jul 6, 2021 at 14:35
  • 1
    It's literally a matter of reading the label. CLR and Lime-Away are formulated to target lime so those would be terrible choices. Dawn is gentle enough for baby ducks. Power washers can cut concrete if you're not careful. You've asked a shopping/product recommendation question and it's off topic here...
    – MonkeyZeus
    Jul 6, 2021 at 14:42

2 Answers 2


I have used TSP ( tri sodium phosphate ) to wash 2 pained houses before repainting; One was in NW Indiana and had sticky dirt. I used a brush but I was much younger, don't see why it would not work in a power washer. TSP was in most detergents but is now politically incorrect. I also use it as fertilizer; It will make your soil alkaline but I have very acidic soil so no problem. You can find it in most paint departments; there will be instructions on the box for washing painted surfaces. Being alkaline, it should not hurt stucco where there are defects in the paint.

  • thx for your recommendation - I'll give it a try once spring comes around and writea n update how it worked out.
    – iLuvLogix
    Dec 6, 2021 at 13:35

JOMEX mixed accordingly spray on let sit use low power electric power washer to clean off.

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