Alpine rubber roof

[Larry16]

My 2016 Alpine rubber roof shows every joint underneath it as black stripes. Scrubbing does remove them. Anyone know what causes this?

[wiredgeorge]

Larry, welcome! Your rubber roof is BLACK and has white pigment infused. When the white pigment wears, black shows through and the more you scrub, the blacker it will become. Black is a sign of wear generally. Your almost new camper shouldn't see this type wear so I would start investigating roof coatings; they are out there and you roll them on to renew the roof. The roof probably isn't exactly rubber; there are several similar materials used so perhaps an expert could jump in and clarify.

[Tbos]

Larry,
My 2019 has the same issue. What did you use to scub it clean? I’ve tried several items and none have not been real successful. The dealer inspected mine and said it just needed to be cleaned. Once you clean it you may consider putting a product on it to help protect it. That’s what I’m going to do if I can get it clean.

[ChuckS]

I like to use a mix of dawn dish soap and warm water in a bucket. I use a soft bristle brush on extendable fiberglass pole on the roof

Wet roof down and apply dawn mix and work it along the stains. Let it sit a bit and brush scrub some more.

I find it removes all the black marks. Also... do this on a cloudy day or when sun is not directly on roof... be sure to thoroughly rinse roof and sides of fifth wheel after.

A California squeegee makes quick work when it comes to drying the sides off after rinsing.

[ajk170]

My in-laws 2018 Alpine has a similar issue, the strips are more spotted and not solid black and my 2105 316RL has a similar black spotting issue along the roof seams- it seems odd that we’d have to do some sort of roof coating already. Are we sure this isn’t some sort of algae that needs to be killed through some sort of cleaner- I’ve seen something similar on “sticks and bricks” roofs back east in Va, NC, SC and Ga.

[JRTJH]

My in-laws 2018 Alpine has a similar issue, the strips are more spotted and not solid black and my 2105 316RL has a similar black spotting issue along the roof seams- it seems odd that we’d have to do some sort of roof coating already. Are we sure this isn’t some sort of algae that needs to be killed through some sort of cleaner- I’ve seen something similar on “sticks and bricks” roofs back east in Va, NC, SC and Ga.

The TPO roofing membrane does not support algae/mold growth. Any "organic coating" (dirt, tree sap, bird droppings, etc) that sit on the TPO surface can (and do) support growth of algae and mold. It's the "organic dirt" that's left on the roof membrane that allows the mold to grow and it's that condition that causes the stain.

The "best practice" to prevent black spots/black stains on the roof is to keep the roof clean. While that's difficult for most of us, DICOR and Alpha Systems both produce cleaners that will help remove the organic compounds and stains, but not much is going to make a dirty, stained roof look like new again. Usually, there's not a need to apply an expensive coating to a relatively new roof and doing so might not be the best idea for longevity of the roof, but it will make it "look good for a while"...

You can download the DICOR "Rudy's RV Roofcare Handbook" here: https://dicorproducts.com/resourcesrudys/

[Larry16]

Bleach and soft brush rinse works great