Mold spots on EPDM rubber roof

[fanabuurs]

Hi there:

Bought a 2005 Georgiaboy Pursuit last June that has an EPDM rubber roof. The rig was, and is in good shape but roof had not been cleaned in quite a while. I cleaned it with elbow greese and Dawn last year and removed old lap sealant and replaced it. It came out pretty good but still has black spots from mold that had been growing before we bought it. Any tips on returning the roof to "spotless" white again... products that work better than others, what NOT to use?? I did clean it again today with a power sprayer first and then Dawn and soft bristle brush and it turned out ok but still the spots. Would love any suggestions or tips.

Thanks

Frank from PEI

[Hpozzuoli]

Mine old roof used to get this way once a year. I use a bristle hand brush with a bucket of car wash. Takes time and elbow grease.

My concern was run off during the wash. I wanted to avoid anything that would hurt the wax. I remember hearing there’s a spot/mildew remover available, but I don’t know much more.

[dkoldman]

17 years old... is Paint not an option?

FWIW, it looks like a speckled pattern; so if you know it is clean and mold not able to grow, you are prolly alright.

But for what you are asking, I would just ensure the roof's integrity and get painted and be good for another 10 years.

[FIRE UP]

Originally Posted by fanabuurs

Hi there:

Bought a 2005 Georgiaboy Pursuit last June that has an EPDM rubber roof. The rig was, and is in good shape but roof had not been cleaned in quite a while. I cleaned it with elbow greese and Dawn last year and removed old lap sealant and replaced it. It came out pretty good but still has black spots from mold that had been growing before we bought it. Any tips on returning the roof to "spotless" white again... products that work better than others, what NOT to use?? I did clean it again today with a power sprayer first and then Dawn and soft bristle brush and it turned out ok but still the spots. Would love any suggestions or tips.

Thanks

Frank from PEI

Frank,
Those spots could also be the natural rubber showing through. We had a '99 Fleetwood Bounder 34V on the F-53 chassis with the V-10 and over the seven years we had it, the White rubber roof almost turned completely black. You see, the way those rubber (EDPM) sheets are made is, the base is black rubber. The top is a coating of white. During natural evolution, time, SUN, acid rain, exposure, road elements and more, the white coating WILL wear off. Seen it many, many times.

I took great care of that roof. It was washed on a regular basis with just soap and water. But, that coach spent ALL of its time in the SUN. I could not afford an indoor storage at that time. When I finally had enough and that roof has migrated from exactly what you're seeing, I'd done the research and ended up putting two coats of Dichor Roof coating on it. It was pure white all over again and it lasted for several years 'till we sold the coach and it still looked great with ZERO black on it.
Scott

[fanabuurs]

Haven't heard great things about painting rubber roofs, any suggestions on that?

[Bobby F]

Two-part Dicor. Follow the instructions closely. Works very well. Looks brand new. Extends life.


https://www.amazon.com/Dicor-Roofing...00BRFS8Q&psc=1

https://www.amazon.com/Dicor-RP-CRCT...s%2C129&sr=8-8

[bizzerbiz]

If you've ever looked carefully at an acoustical ceiling tile. It looks a bit like your roof. Pitted. Just could be by design.

[Winemaker2]

I have had similar looking black spots on boat non- skid surface... the pores / recesses are difficult to clean.
I have had some success with Spray 9 and a little patience and a brush.
I use Starbright Deck Cleaner on a regular basis and it works well... again brush and it takes some time to work.

[BOOZE TRAVEL]

Awsome cleaner. Biy a bottle of Awsome, wet the roof, spray some of it around and wash with a long handle brush.

[Ray,IN]

Over the years I've gotten great results from scrubbbing the roof with a mixture of 2-3 oz bleach and a cup of car wash soap in a 5G pail of water. I use an old RV wash brush on a broom handle to scrub the roof a few times a year.
My RV roof returns to a very white surface again after scrubbing off the dirt that falls out of the air and the mold/mildew that results.
I also use this same mixture when washing the rest of the RV. Awnings and plastic trim are also free of mold/mildew.

[Gary RVRoamer]

You don't "paint" a rubber roof, but you can brush or roll on a suitable liquid rubber coating, e.g. Dicor rubber roof coat, Henry's Tropical, etc.


But first try strong detergent & bleach applied with a medium-bristle brush and rinsed well after. Or if you prefer, one of the more expensive commercial "rubber roof cleaner' products. It may remove all the black stuff. If it doesn't, it should still kill the mold in preparation for the over-coating process.

[astrnmrtom]

Detergent and bleach. May take more than one application. I've used a diluted bleach solution by itself and you'll want to give it some dwell time. Apply the solution and let it sit but keep it damp, don't let it dry, then brush or rinse. If you have some patience and store the rig outside, Wet and Forget works very well.

Is the mold flush or is it raised above the surface? It has a bit of a Lichen look. Lichen will take more scrubbing but Wet and Forget will get rid of it too. Try the fingernail test. Lichen sits on the surface and sets roots into the roofing. Get it wet, and try to removing it with a fingernail. Mold will come off that way too but it grows more into the surface and a fingernail will only remove the surface part. Lichen will mostly come off but leave a slightly rough/pitted stain behind depending on how long it's been there.

As for the suggestion for Totally Awesome! cleaner, be careful. I love the stuff, but have used some version of that cleaner for 40+ years and while it really is Awesome!, it's also very easy to damage painted surfaces with it. It's primarily a degreaser, and you can take the shine off paint and aluminum with it especially of it sits too long, or dries on a surface. One of the active ingredients is Lye which is why it cuts grease so well. We used a commercial version and I saw people do a lot of damage with the stuff, usually to painted surfaces. Like I said, I love the stuff, but always use it with care.

Depending on how stained the roof is, you may never be able to restore it to a like new whiteness without recoating. If you do recoat, make sure you kill the moss or lichen.

Get down real close and look at the stains. It's not unusual for mold or lichen to grow on drops of tree sap.

[RVRoofMagic]

we have seen this with many of our customers roofs. The problem is if you don't kill the mold spores matters will just get worse. We always suggest to our customer to wash their roof twice a year. The rv repair shops we have worked with swear bu our roof protect cleaner. Once it is opened it reacts to air and it actually emulsifies the contaminates on the roof and also kills mold spores.



Of equal importance is when you are look for a roof coatings be sure that it contains mildewcides to help avoid mold growth on your newly coated roof !


here is a good video on how to avoid mold on the inside of your unit as well

https://www.youtube.com/watch?v=-kURu6dreco