Keeping your polyvinyl chloride (PVC) roof clean isn’t just about appearances, it helps extend the life of your investment and keeps your roofing system performing at its best. At Grell Roofing, LLC, we often get questions from building owners about the right way to clean a Duro-Last® roof and which cleaning products are approved for use.
The truth is: there’s no one-size-fits-all solution. The best cleaning method depends on what type of pollutant you’re dealing with. Below, we break down the most common roof contaminants and how to safely remove them.
1. Removing Dirt
Dirt is the easiest contaminant to handle. For general cleaning:
- Use a mild cleanser like Simple Green® or Spic and Span®.
- Spread the cleaner across the roof surface.
- Scrub with a push broom.
- Rinse thoroughly with a hose.
Pro Tip: If you plan to weld on your roof afterward, spot clean those areas with acetone (only after rinsing the soap away), since soap leaves a film that can interfere with welding.
2. Tackling Grease
Grease buildup is common for commercial roofs, especially restaurants. For grease removal:
- Use a heavy-duty cleaner like DeWitt’s Citrus Cleaner.
- Expect to scrub a bit more aggressively depending on the level of buildup.
- Rinse with a hose after scrubbing.
This method ensures grease is cleared away without damaging the Duro-Last® membrane.
3. Cleaning Biological Growth (Mold, Mildew, Algae)
If you see dark streaks, green patches, or signs of growth, it’s time to act. For this, Duro-Last® recommends Wash Safe™ ROOF WASH.
- Mix ½ cup of Wash Safe™ powder for every gallon of water.
- Allow it to activate for 15 minutes.
- Apply with a pump sprayer or similar method.
- After the growth dies, clear it with a hose, push broom, or power washer.
Important: If you use a power washer, keep the pressure under 1000 psi, use a fan tip, and hold the nozzle at least 12 inches from the roof to prevent damage.
4. Dealing with Asphalt Stains
Asphalt is the toughest contaminant to remove because it often leaves stains behind. For this type of cleaning:
- Use Bulldog® Asphalt Remover, or a citrus-based or white wall cleaner.
- Scrub with a push broom.
- Rinse thoroughly with a hose.
While stains may remain, this process reduces residue and prevents further damage.
What NOT to Use
Harsh solvent-based cleaners should never be applied to a Duro-Last roof, as they can damage the membrane. Acetone should only be used sparingly for welding prep — never as a general cleaner.
Keep Your PVC Roof in Top Shape
A clean roof is a healthy roof. By using the right products and techniques, you can protect your investment and extend the life of your Duro-Last roofing system.
Not sure what kind of maintenance your roof needs? Grell Roofing offers professional roof inspections and maintenance programs to ensure your commercial roof stays clean, leak-free, and ready for the long haul.
Contact us today for a free inspection or maintenance plan tailored to your building.
