Streaks on siding after cleaning

Pictures from a residential job i did yesterday. Our company does 6-10 houses everyday. Once in a while we get some callbacks about streaks on the siding. Any idea what might cause that and how to clean it? We make sure to rinse everything with water real thoroughly

What is your procedure?


We usually put 25gal of some 12% bleach in a 30 gal drum and add 5 gal of water and half a bottle of ajax. Then spray it through downstream and rinse with water

1 Like

Part of the problem is the Ajax, part is water under the siding weeping out, maybe oxidation. Rinse with the laps, not against. A light mist might fix it.

1 Like

Go back and soap and rinse with a light mix. Very little SH and a drop of soap. Rinse the crap out of it. The streaks will still be there but look better. Let the house dry for at least a week before you go back. It will go away. Some siding takes forever to look dry. Also, never clean that house again because it will do it every year. It’s happened to me several times. Recently was this summer. There are a lot of threads on it from this summer.

If you do nothing it will look better in a few days. As long as it gets a few dry days.

Too much soap, don’t use dish detergent. Light final mist like @Innocentbystander said.

1 Like

You invested in that trailer build, but you use Ajax??? Why? You obviously understand the need for professional tools, now apply that to your chemicals. I use Elemonator here is the link:

You can buy 5 gallons for just over $100 and it will last you a really long time. Lately I have been using 1 or 2 ounces per 5 gallons of SH. Super cost effective and rinses easily.