Worth the risk?

Tile roof needs cleaned. Copper gutters are already green/black. The homeowner just had a few new gutter pieces (patch work I believe) put on that are not shown here. I’m taking a look at it Thursday. He seems to be fine that the couple new pieces of gutter will not look new if I clean the roof and get SH on it… which ultimately will happen. I have researched a bit and have seen where someone does roof cleaning with copper gutters all the time and others simply want to walk away.

Any roof mix on the copper gutters will likely ruin the patina and once it’s gone it’s hard to get back. Personally, I’d walk.

1 Like

I’ve been searching for pictures of how it would ruin it but haven’t had any luck. I can’t say I’ve seen the results. What exactly does it do to the patina?

I’m doing 70 down the highway right now but when I land here in a couple hours I’ll see if I can find the thread on here with pics of one messed up from roof mix. I wanna say they had to hand polish with Brasso to get it back to decent looking.

1 Like

Well here’s the thread I was thinking of and it doesn’t look like we ever got an answer on how he fixed it.

@Harold did you ever resolve that issue?

Notice he says he scraped it with his fingernail and it revealed “fresh” looking copper. That will stick out like sore thumb.

I had read that one. However, the gutters on the roof I would be cleaning already have the patina look like the downspout on this thread. I’m wondering if it can get much worse?

I did read that. I figure it can’t be any worse than the sections of new copper the owner just had replaced.

Oh, I see. That’s a tough one. Are they cool with a test spot?

It’ll turn them green where the sh runs down on them. I had that happen on some copper that was used on top on a bow window. That was with house wash mix… They were replacing it so were not worried about it. It’s not like the whole thing turned green but definitely affected them. You’d probably end up having to clean all the gutters with an acid to get them to look new. Not sure if the homeowners would want that but I know I wouldn’t want to be the one cleaning the gutters. :grinning: I’d pass on the whole job unless someone can chime in with more experience in the copper.

I’ve only worked with copper once, but did research as well. Prewetting and having someone spraying the gutters whenever you’re spraying bleach will definitely work. When I did mine, I was spraying 2-3% on stucco walls, with a copper roof and gutters. Prewetting the copper and then rinsing the overspray worked without disturbing the patina (I did do a test spot before choosing my method). However, I also had some copper stains to remove from the stucco, and One Restore removed the patina, leaving shiny copper exposed in my test spot. Keeping the copper sprayed the whole time I applied the One Restore diluted it enough that I had no issues.


Yes, I am going to do a test spot Thursday.

Look at the gutters in the picture though. They are already green…and black. I told the owner about the new pieces and said they would turn.

In all seriousness I know that ketchup will make copper look new again. I had an old copper pot my aunt gave and covered it, let it set overnight and bam. I do understand this may not be feasible in the given situation but if the price was right I’d ask Heinz or Hunt’s?


Dude, that’s a heck of a roof. Pretty home. Charge accordingly and go for it. They’re not paying you to spray the gutters, so don’t. Just have your ground guy hit them if you happen to get a little overspray on. Just plan on moving your ladder more and you should rarely, if at all, hit the gutters. Better get some slo-mo or triple up on your roof snot with that pitch and that dirty. Probably going to have to hit the whole thing twice. You should make a stroke on that thing. Not that hard. Good luck with it and post some after pics.


Update: Did a small test spot on one of the roofs. Hit it with 5-5.5% from a pump sprayer. Didn’t look like it even phased it. Waited 20 minutes, hit it again…nothing other than a little moss on it that turned white. Hit it a 3rd time and still didn’t look like it was affecting it. :thinking:

Let’s get our resident tile roof expert on it. @garry.cooper - Jayson needs some help on this one.

I’m gonna start invoicing you Rick!

Did a beautiful black slate roof a couple years ago, had 30 year old copper gutters, wet them down and cleaned the roof, rinsed after, didn’t affect the patina. I’m no metallurgist, so proceed with extreme caution.

1 Like

Thanks, Gary. I also sprayed a little spot (twice) on a downspout that didn’t seem to affect the patina at all…not rinsing it. My concern at this point is why the roof tile didn’t seem to be affected. 60 degrees out and 5-5.5% didn’t seem to make a dent. I might go back tomorrow and check that test spot and hit it with a little stronger mixture to see if I can get it to start coming clean. In looking at this roof in person, I am starting to lean towards walking away as I might need a lift and there are many obstacles to maneuver around. The owner said she thought a quote on replacing the roof was well over 6 figures, so I think she would be very happy if I could get it clean for a few thousand. There are also a few houses around her that need their slate roofs cleaned so it could lead to a few more jobs. @Racer , I’m thinking this might take several applications. Not knowing is making it hard to come up with an estimate. House was built in 1932. I’m assuming original tile.

Sorry I just need to ask, do you have specialized roof cleaning insurance? Where I live they have it separate and it’s double what normal pressure wash insurance is. I know you’re having trouble with this and would hate to see you get docked for something unforeseen on a 90 year old house.

I stopped doing window cleaning on those a while back, too much risk.:flushed: