A TOP-TO-BOTTOM RV WASH AND WAX should be part of your seasonal maintenance routine. Some RV owners even clean their campers after every trip — but we all know it’s not always easy or practical. Even with your best care and cleaning efforts, black streaks can still develop on the exterior walls of your RV. So, let’s explore why they form and how to remove black streaks from an RV.
Key Takeaways
- Black streaks form when rain or condensation carries dirt, grease, and organic particles down RV walls, drying into visible stains that can lead to mold or mildew if not cleaned regularly.
- Removal starts with cleaning the roof, then using RV-safe black streak removers or approved alternatives (like Simple Green, vinegar mix, or dish soap), applying, scrubbing, rinsing, and drying the exterior.
- Prevention involves maintaining a clean roof, waxing the exterior, avoiding tree cover, and using RV covers during storage to reduce contaminant buildup and streak recurrence.
Why Do Black Streaks Form?
When water, either from rain or condensation, drips down the side of your RV, it carries dirt, grease, and other grime with it that can form black streaks when dry. As some of that water evaporates before it drips to the ground, it leaves those contaminants behind.
Technician Tip: Organic airborne particles in the mix can cause mold and mildew, which actually penetrate surfaces and are very hard to remove. A thorough wash and wax at least quarterly can help prevent it from taking hold.
What’s the Best Black Streak Remover?
Well-known brands like Thetford, 303, and Camco all make RV-specific black streak removers in convenient spray bottles. (If you need a bulk solution, Bio-Kleen offers a one-gallon jug).
But are you limited to these RV-specific products?
We must be careful here because using unapproved cleaners could void warranty protections. The manufacturer of your specific RV — or the provider of any extended warranty —is always your best resource to ensure you aren’t using a cleaning solution that jeopardizes your warranty.
In the vast majority of cases, you’re safe with a product made specifically for RV use. However, in the interest of giving you options, check out these other solutions that experienced owners and technicians have found useful for black streak removal.
- Dawn dish soap
- Full-strength Simple Green
- LA’s Totally Awesome Cleaner & Degreaser
- Purple Power
- WD-40 (only on fiberglass or aluminum-sided RVs)
- Homemade vinegar and water mixture (3 parts water to 1 part white vinegar)
Of course, every product manufacturer will have recommended instructions for best use.
How To Remove Black Streaks
The temptation is to clean black streaks as soon as they appear. Surprisingly, that’s not always the best place to start. Black streaks are among the most unsightly things you’ll see on your RV’s exterior, but before tackling them directly, give your RV’s roof a thorough cleaning. If the roof stays dirty or your RV sits uncovered, those streaks will just come right back.
That said, to clean black streaks off your RV, here’s what you’ll need:
- RV-safe black streak remover solution
- Soft cloth or brush (for removing streaks)
- Water and/or bucket (if you don’t have a spigot and hose available)
- Soft cloth (for drying)
The general process is simple: some call it spot cleaning, but we’re really streak cleaning here.
- Get the affected area wet.
- Spray the solution over the affected area and let it sit for 30-60 seconds.
- Use a cloth or brush to scrub away streaks (varying degrees of elbow grease may be required).
- Rinse with water and repeat as needed.
- Dry thoroughly.
Technician Tip: In case of deeper damage, the surface may require labor-intensive buffing and polishing to restore its appearance. For damage that buffing and polishing can’t remove, the RV may have to be completely refinished or wrapped.
After you remove the black streaks to your satisfaction, it’s a good idea to complete your RV wash and wax to remove any remaining dirt and residue.
Prevention Tips
Now that we’ve removed those ugly black streaks, here are a few quick tips to keep them from returning:
- Keep your RV roof as clean as possible.
- Regularly wax the exterior so water beads and carries more contaminants with it.
- Avoid parking under trees to minimize exposure to sap and animal waste.
- Use an RV cover when your camper is in storage.
Technician Tip: Parking in the shade slows UV damage, but encourages mold and mildew development.
Now that you know how to remove black streaks from your RV walls, use these additional resources for other essential RV maintenance tips:
- How To Keep Rodents Out of Your RV
- Why Should You Cover Your RV?
- How To Clean RV Holding Tank Sensors
Do you have a go-to black streak remover? Let us know how you deal with this RV maintenance issue in the comments below!
