Uneven drying on oxidized vinyl siding

Hello, PWRA…here’s a link to a thread I started over at the WCRA that I’m looking for a little feedback on. Pictures are on that thread.


You have to always test the siding first and see how oxidized it is.

You need to adjust your rinsing when dealing with heavily oxidized areas.

Heavy rinsing results in exactly what you have in those pics.

You want the water to dry on the siding and not continue dripping that will cause the marks.

You really can’t rinse past what a rain storm would do.

Always explain what oxidation is to the client before and even show them.

Thanks for you feedback. In the past, with heavily oxidized vinyl, I’ve disconnected the DS injector and rinsed with my low Pressure tips. I should have done that this time for sure.

Do you think a re-wash will improve the situation, or do you think those drops will even out over time?

I had the exact same issue last week and posted about it. I thought your pics were from my job. However I had it all over house. I rewashed 3 days later but I soaked the siding so it was wet, washed with my normal mix, SH and Elemonator but I used less SH. Then I rinsed it heavily. Came out perfect. I think my problem was a combination of 90 degree day and soaping drying on wall and oxidized wall not allowing water to dry evenly.

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Thanks for the feedback, Bill. I’ll look up your old post. Did you use a rinse nozzle to rinse or did you use a soap one to bring the pressure way down?

It wasn’t hot today, but it was very sunny and very windy. I don’t think anything dried on, but there were a lot of nooks and crannies to dripping.

On the plus side, the customer is super cool and understanding, and he has acknowledged that the condition of his siding is likely the main contributing factor in the outcome.

That looks a lot like dirt running out the weep holes to me. Wasn’t rinsed well enough. Definitely a re-wash with lots of rinsing.

Thanks, Steve. I think I may have been rushing since it is a commercial property where everyone wears nice clothes and drives BMWs, and I wanted to get out of the way before they opened so I didn’t cause trouble for anyone. Probably should have just scheduled this job for a weekend or evening.

I rinsed using my Jrod rinse nozzle, fan tip for lower portions and my Jrod stream soap tip for high spots.