Metal roofs

Anybody cleaned any metal roofs? Got my first one to do when it warms up. Not sure what chem to use.

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I’m not sure but I have heard under no circumstances should you use Gain dishwashing detergent. It puts black specks on it that can’t be removed. I read that on the roof cleaning forum.

That probably isn’t much help but maybe it will help someone. I know it helped me when I read it! LOL

Use a 3-4 percent SH mix with a surfactant and rinse rinse and rinse everything some more. You can burn up some stuff quick with the run off speed of a metal roof.

If its accessible you can even use some decent pressure on it if the roof mix recommended above isn’t cutting it. Also, if you have some PM for Bleach or Bleach Wash that’s a quick way to neutralize the effects of the SH on the metal as a post rinse. You can just leave it on there.

Just got my first one but the owner doesn’t want any bleach used. What else can be used?



Try citriclean, but I would add something to thicken it up and help it stick for a while. We use it it clean the interior of tankers before they ship out. Any aggitation you can do will help for sure. BTW, I have not cleaned a metal roof per say. I’m just speaking on my experiences with cleaning metal in general and logic

Unless you don’t mind being tied off walking the roof blasting away I would pass unless you can sell yourself and your roof mix which has liquid chlorine and how everything will be diluted down and rinse very heavily.

An once you start walking the roof or hitting it with pressure there is no going back because of oxidation removal.

And the chances of getting it all even are slim to none.

I either do no pressure or pass.

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Don’t use dish washing detergent because it will definitely get rusty. Just clean it with water and if it dries fast you should put a thin paint to protect its surface.


This advice hurts my brain thinking about it.:confused:


From what I am reading I would pass if I were you. Using high pressure you could blow out the rubber washers on the screws which could equal costly repairs because of water damage.

Remind the customer no cleaning process uses only water

I did this job a few weeks ago and it went ok. I down streamed a light roof mix on the metal a couple times without letting it dry and then rinsed it off. It came clean but I couldn’t do anything about the fading.

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Just normal roof cleaning mix used here.

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