Will F13 fix this?

washed my parents house the other day and after it dried i noticed on one side of the house these spots appeared… i tried to rinse again with the garden hose and it looks fine wet but once it dries they come back. i think it has to do with the oxidation. my best guess is that i may have held the gun too close to the house in this section, which may have taken some of the oxidation off. the rest of the house is perfect. i would appreciate someone else’s input before spending the money on the F13, thanks

What was your house mix comprised of?

Let it dry for at least a week. It will look better maybe back to normal. If not go back and restart with a super light sh mix and surfactant. First wet siding well, soap for a short dwell and rinse very well. Let dry for at least a week. If it was a customer never wash their house again because it will do it again. I’ve dealt with this several times.


Don’t use any products to remove the oxidation before trying the above unless you just want to remove the oxidation because it’s your parents house. Good practice.

pulling 10% SH through a 5-8gpm injector… but i was using a 2.5 gpm machine at the time because my new 5.5 wasn’t set up yet

1 Like

luckily not a customer, i just got the truck built a week ago so doing a few family members houses to test it out. i’ll give it a week and see how it looks, thanks for the advice

Sometimes a couple good rains and what @Clean_Blue said, time.

As a soft wash person/professional painter, I can tell you right now that it needs two coats of exterior acrylic paint.

is this just something that happens on certain houses or can this be avoided? i’m curious if it was me shooting too close to the house in that area or maybe something else? since it only happened on one side of the house, and it’s not the whole side, it’s just in one corner

That color, plus the fact it’s oxidized, and I’m guessing the side that looked like has the sun shining on it when you washed it? If it dries fast but water is still dripping from seams or weep holes you can get weird spots. Normally time and a nice steady rain will help it go away.


What @Nickski said.

yes the sun was on that side when i washed, and most of the spots are right around the seams. it rained for a few hours today but the house is tapered out and there is a small tree covering the affected area so the rain barely touched it. so if a week or two goes by and it doesn’t change and i had to fix it myself my options are oxidation removal or painting…?

That’s worst case extreme next steps. Go wash it again when it isn’t sunny, rinse the crap out of it and see. Lightly rinse, don’t go blasting it. Use a garden hose if needed.

You should make it standard practice to MIST the siding just before you roll up your hose. Like a super quick (but even) mist as you walk the hose end back to the trailer to roll up. It will eliminate 90% of weeping issues. Especially if it’s oxidized.


m5 twist on the wide fan is fine for that final mist? i’ll do that from now on thanks. would hate for my first legit jobs to turn out like this and get a bad rep as a new company… any reassuring things i should know to say to a potential skeptical/angry customer?
if i paid someone to wash my house and it turned out like this i wouldn’t be too happy with the worker

M5 twist should be fine. I have one but never use it because it mists too much for my liking so it would probably be great for that. My best advice is to just pay attention to how close you’re standing when you’re rinsing and do a light, even mist as your past step before you pull tape.

Update on the siding, glad i didn’t place the order for F13. after 5 days it cleared up pretty well and now it’s been 10 days and i can barely notice the spots anymore. thanks to all who told me to just wait it out


Please hold off on the advice until you get a little more experience.


As a 20++ year professional painting contractor, I can assure you that it’s screaming for paint. As a painter, we have to know cleaning AND coatings!!!

Lulz. Well that didn’t go as planned eh Mike?

1 Like