Remove black stains from brick?


#1

Normal brick washing mix didn’t touch these black stains. Any advice?

Thanks much!


#2

Have you tried using SH? A good soft wash mix should remove that pretty easily


#3

5% solution of sodium hypochlorite with surfactant, may need as many as 3 applications. No need to rinse between applications. It WILL disappear, or my name isn’t Mr Sparkle!


#4

Yes, I use SH in my normal solution… even made it hotter and nothing doing…


#5

How strong? Maybe bump up to 50/50 re hit stains multiple times.


#6

Yea, I did that, kept making it hotter and hotter, went over it at least 4 times… stymied.


#7

Are you allowing some dwell time? Let it work, reapply if needed… rinse… Also post treating well help as it dies


#8

Only other guess is that’s it’s oxidation run off from other surfaces… maybe a metal roof?


#9

I see that all the time on flat blacktop roof buildings. A strong degreaser and pressure takes it off


#10

ARe you applying it direct? With a pump up or 12v?


#11

Are you using 12% SH @ 50% with several applications? If you are and still not working check the strength of your SH on something else as it may be weak.


#12

was over 50/50 by the 3rd pass… going to drive by and take a look at it this week and see if it got better.


#13

I will give that a try and see if that gets it.


#14

direct downstreaming


#15

Used the same solution on a house after this (added more elomonator) and it worked super fast on the gunk, so the solution was good.


#16

So you’re downstreaming a 50/50 solution? Maybe a 1% solution? I believe you need a 4% solution for dirty brick.


#17

Downstreaming? That’s your issue…


#18

Look, if you want to beat this, you will need to follow directions. It doesn’t really matter who’s, but you WILL beat this. Just pick somebody and follow instructions.


#19

I get the impression @florida_condo_cleani may have it nailed. Really looks like it’s coming off the roof.


#20

What is direct downstreaming? Not sure I’ve ever heard that term.