Black siding fallout? pt 1, 2, 3

What kind of stain is this? I washed this house and everything looked good then the customer sent me these the next day. It looks like fallout but I’m not sure. I’ve never dealt with anything like this in the past so I’m not even sure what to try to get it off. I’m going over there this weekend to see what I can do and need some things to try other than degrease in case it doesn’t work

Almost looks like you didn’t rinse enough. Do you use a surfactant?

Did you enhance the brightness/contrast on the photo? If you didn’t and that siding is supposed to be black I think you got bigger problems to worry about…

But to answer the question, no that’s not what fallout would look like… looks more like residue from something that either got washed out from behind the siding or like was mentioned soap that didn’t fully get rinsed and as it dripped down it dried.

Nope this was just downstreamed 12.5%. No surfactant. I feel like I rinsed this area pretty good, but that could very well be the case

No these photos are not edited in any way. These were sent to me by my customer. What do you mean I may have bigger things to worry about? The siding looks good to me other than the stained areas. I’m thinking the most realistic thing is dried soap, but I’m not sure how that would have happened. Should I resoap it and then rinse again really good?

You said you did not use any surfactant . Not having a surfactant with your bleach is not the proper way to wash a house.


If the siding is supposed to be black, those photos make it look very washed out… I’m guessing since the homeowner didn’t mention it as a problem (damaging the paint that is) they probably just enhanced the photos to show the problem areas better.

My guess would have been dried surfactant since the drip pattern and when dried it turns a a whiteish stain, but since you said you didn’t use any I’m not sure. Is this a newer build? Did they have their windows replaced recently? Did you check for oxidation before starting? Could just be residue from construction that finally got washed out but not rinsed off completely. Rewash it but spend 75% or more on the rinsing.

Thank you for the help Anton. This is solid advice. It is a newer build so it could very well be construction residue. I think that’s what the problem most likely is. I did check for oxidation and there didn’t seem to be any. Especially not in the picture with the window because that’s under a covered porch that hardly gets any kind of weather at all.

The siding isn’t black, it’s a nice dark gray. Here’s a better photo the client sent

Fallout takes a few years and usually just builds up right under eaves, maybe 2’ or less. Looks like a rinsing issue to me.

In a side note be very careful washing any dark colors like that, I usually either turn them down or strongly advise the customer of potential issues.

Gotcha. What kind of issues can I run into with the darker colored siding? I have it a lot near me in Michigan and it’s always on the very nice homes. The richer people around here tend to get darker colored homes black is a pretty common color around here

Sherwin Williams has a organic pigment based paint… a lot of the darker colors (navy, red, green, browns, etc) have issues because the SH will effect the pigment, since it’s organic, and leave spots everywhere. Ask the homeowner if they know what paint was used or do a test spot in a hidden location if you are ever unsure to make sure you don’t have to pay to repaint the whole house.

Always test in an inconspicuous area if you aren’t sure. A spray bottle with SH, surfactant and water, give it some dwell time then rinse.

It looks like your lines are from the runoff around the windows and the weep holes on the siding.

Here is a quick link from the googly
An Easy Guide to Understanding How Surfactants Work | IPC.

Chances are that using a surfactant would have carried the dirt/grime off the wall better and wouldn’t have left a trail behind. Work with the siding overlap, don’t spray into it - go with it. Sometimes that is impossible, as the siding people were hacks or homeowners did some “repairs” themselves and the siding overlaps each way.

Unless I have missed something in this thread, this is vinyl siding we are discussing here. If this is an unpainted vinyl surface - organic paint issues should not be an issue here. My experience only, your mileage may vary.

Guys, slow down and think about it. You’re all way overthinking this.

@LoganWashesStuff what you, and your customer, are seeing is drip marks from the weep holes in the vinyl siding. Those areas you pictured are tight quarters to wash in. When you’re washing vinyl siding, you want to stand back about 10 to 15 feet from the siding so that you don’t push water into those weep holes. When you’re done rinsing a side, go ahead and move to the next side. When you’re done rinsing the next side, go back to the previous side and put a light mist on the entire side. The mist helps smooth out any spots where the weep holes have dripped water/dirt/debris from behind the siding. Explain to your customers that there may be spots like that remaining until the next good rain comes through and Mother Nature will take care of the rest.

Do be careful washing dark vinyl. It can be tricky and you have to slow down–especially when rinsing–to make sure you leave as few spots like that as possible.


Some of you probably saw my first post with these photos my customer sent me

Well, I went out there and rinsed wbeeyrhjng really good and the overall big streaking from those photos went away, but another issue that the customer pointed out when I was there was these little streaks, and they didn’t come off with just a rinse. How did I cause this and what should I try to fix it?

Your situation is reminding me of a similar home were nothing would clean up the siding, it always looked dirty. Find out from the home owner if this is Nailite siding.

I’d probably redo the whole thing and this time rinse the snot out of it.

I didn’t check your application method, are you using an xjet, downstreaming…what is your SH and soap percentage?

Tell him to call you back in a month after it rains 4-5 times hard.
If he won’t go for that, you may have to re-wash. The problem you have is you may have rinsed too much. That’s just where water, probably somewhat dirty has dripped. Next time stand further back and rinse on diagonal with the overlap, thoroughly but lightly. 9 times out of 10, most the drip marks come from the lower 1/2 the house or wall. Do like William told you and come back with a light mist coat once it’s dried a little.

Down streaming 12.5% so I’m at roughly 1.25%.