Roof cleaning rust stains

Guys, I’m under the gun. I have an appointment at 10 am to inspect a house .that has bad rust stains on it. Soft wash? Front 9 Barc? X Jet? I’m just not sure.

This confuses me and makes me think you shouldn’t be washing anything if you don’t know the difference between chemicals and applications. It’s rust so you’ll need a rust remover…that’s an acid. F9 barc is a good option but do a thorough search on here before you do the job. Take in mind the chem cost and the amount of time it may take you before quoting. Good luck.

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Racer did this one with F9 and it came out great:


You can do it sometimes with Oxalic, but everytime with F9. They need to get the problem fixed before you do it or it’ll be back, rusted drain pan. It will probably take spraying it several times, about 5 min in between and don’t rinse till the end. It helps to spray it and then lightly scrub it in with soft brush. Just mix the F9 in a spray bottle 1-1. Lightly pre wet the shingles, damp but not real wet before you apply. Don’t let it F9 mix dry on there.

Warn them that it may lighten the roof shingles in that area a little, but usually after about 6 months as they get dirty again you won’t see it


I’d forgotten I’d even posted that on here, lol.

How do you have a pic now if you have an appointment at 10 to look at it?

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I drove by it yesterday evening after working on another roof. That was a simple roof clean that had gloeocapsa magma on it. I’m glad that I did because I know that there is unsurpassed knowledge on this board. I’ve been lurking for six months, but this is my first post. Thank you for those that have responded to this post and to the many others who have shared your knowledge with newbies

I know the F9 will get it off the siding because I’ve seen that before. But it should also come off the glass as well, correct? With multiple applications I assume.

Racer, thank you so much. Max, thanks for your pm’s the other day.

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Be careful on the glass. Maybe do a small test spot in the corner just to make sure it doesn’t etch it or anything. They use acids to do glass etching but I doubt F9 Barc is strong enough to hurt it but you never know. You could probably get by with oxalic on the glass and window sill which is a weaker acid so you wouldn’t have to worry about it as much. I’d still do a test spot.

No problem, I didn’t realize it was you. Listen to these guys and it’ll work out :+1:

So here are the up close pictures.

I think I will do what Racer suggested. It looks a lot like the pictures that he did (the before picture, not the after) in an earlier post.

Again, thanks to all.

Now to price the job out! Oh boy!

Keeping in mind of what @racer said, guess how much chemical you’ll use and how long it’ll take you. How much do you charge per hour?
Time + cost of chemical used = your quote.
Over estimating by a bit is your best bet since you haven’t tackled this type of job before.

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Max1, thanks so much man!

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@Lifouman I would suggest you tell the owner to re route that pipe. That rust stain will always come back, bad for them good for you I guess.

Do us a favor and take after pictures along with your process. I’ve only been at it a year, thankfully haven’t run across something like that.

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Has anyone tried aluminum brightener on anything that bad yet. I get that phosphoric works an all,but so many applications and cost. Just curious.

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I want to see you two step a house! :wink:

The glass will clean up easily - be sure to pre-mist glass and lower your dilution to 1 part f9 to 3 parts water. Once clean spray some soapy water on it and rinse. When I did the one you saw, had 3 spray bottles, one with water to mist, one mixed 1-1 and one mixed 1-3 for glass.

Also, if any algae or whatever, clean it like you normally would before you even start the rust removal steps.

I think I was about $250 to clean the one I did.

That, and muriatic, is all I used on any rust stains

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