Black spots on TPO roof

[tonyz1]

Found these spots on roof while washing it down last week. Scrubbed pretty hard till I got a little worried about "injuring" the roof material. The two spots in pic are the worst as they were actually two loose spots, but there are a few small others scattered around. Looks like a black mold of some kind. So need help trying to figure what to use on them to remove without damage. Thanks, all theories and suggestions are welcome.

[tonyz1]

Wow, a first for me on here. 140 views and no responses. Anyway, I talked to Alpha today and they told me I could try bleach on a rag to try to remove spots. Followed by a quick rinse. Guess I'll give it a whirl. Happy camping.

[jtaylor1920]

First guess would have been burn spots based on the picture. Like embers from a fire sitting on the roof material.

Does your rig sit under a tree?

Let us know what the bleach does.

[Fluffywhitedogs]

It does look like damage rather than staining, but hope for you that it’s not!

[jeff64]

Did you try the old standard of Dawn, hot water, scrub brush and a little elbow grease. Usually sufficient and you'll be the only one who nose!

[TitanMike]

RV roofs pick up all kinds of "stuff". Drops of tree pitch when parked under trees at a campsite. Globs of oil or grease that get's thrown up from vehicles ahead of you on the highway. Not all of that gets deposited on the roadway immediately, especially if flung off a hub, drive-shaft, suspension part that was over-greased. Even road tar during the summer months can be flung into the air and drop on an RV roof.

Once these "gooey" deposits attach themselves they tend to attract all kinds of particles from the air like diesel soot, road dirt/dust, pollen. Bird Poop can also attach itself pretty firmly.

I just washed my roof and noticed a few spots similar to the OP's and using simple green, a scrub brush, and patience, did a good job of removing them.

One thing to pay attention to is any damage that might occur from gravel that comes flying out of the sky. Same pieces that ruin windshields can leave nicks in the roofing matrial and if it makes a small penetration, eventually you'll have water under the membrane.

Pays to do roof maintenance at least twice a year.

[MNtraveler]

Originally Posted by tonyz1

Wow, a first for me on here. 140 views and no responses.

It's very hard to tell what it is from the picture. Sorry.

[quick83]

It may be chemical got on it. Is tpo one piece? If it is like edpm the top layer could be gone due to something got on it. Not a big deal if that is the case. You could just put some externabond tape or dicor caulk on area for protection. (Will look doctored). If it’s just a stain, we are allowed to use acetone to clean for applying tape, so why not for a bad stain?

[tonyz1]

Thanks for all suggestions. Yes it is TPO roof and it is not burn damage but some kind of mold. There are some other smaller spots of same stuff scattered around roof but not as noticeable. These two spots weirdly showed up on two small air bubbles under roof material that went down and left the slight wrinkles you see in the pic. I scrubbed with spice and span but was probably a little too gentle on it because of the wrinkles. Will scrub again with the bleach and see what happens. Alpha also told me to use my own discretion on how hard to scrub, whatever that is supposed to mean. Be a few days before I can get on roof and let you know what happens.

[john5646]

I have this also. Alpha cleaning suggestion doesn’t work. I’ve tried many things with little change. Mine are at seams of plywood every four feet. Not warranty as roof is not defective. So they’re telling me.

[flhf150]

I have the same stains at every joint. I took dawn soap, a bucket, soft bristle brush and hose on roof yesterday. Got a lot of the black spots off, but not all of them. How do I know if I have a tpo or edpm roof?

[john5646]

Alpha roof is neither, they call it super flex. If you go on there website they go as far as to say not to use dicor, sealants. They sell there own product. It’s priced the same so I’m using it. Not going to beat that subject is my thought.
So alpha take the warranty stand that cosmetic is not warranty. There warranty is only that roof will keep water out....