How to Effectively Clean a Duro-Last® Roofing System
I get several calls a year from building owners and contractors asking about approved cleaners for their Duro-Last Roofing System, or confused as to why a certain cleaner didn’t work for them. It’s important to note that for a cleaner to work effectively, you need to know what it is you’re trying to remove. There is no one-size-fits-all solution for cleaning a Duro-Last Roofing System, so in the following article I will provide an overview of approved cleaning solutions and appropriate usages for each.
Roof pollutants that are most commonly encountered in commercial installations include dirt, grease, biological growth, or even asphalt. Let’s break down cleaning options based on these four categories:
1. Dirt is the most straightforward to tackle; requiring a mild cleanser, a hose and push broom. Duro-Last recommends Simple Green® or Spic and Span® brand cleaners for standard dirt removal; spreading the cleaner around the rooftop and scrubbing with the broom before rinsing with the hose. If the roof requires welding work, acetone will also be needed as soap leaves a film that makes welding difficult. Spot clean areas that must be welded with acetone once the cleaning solution has been rinsed from the roof.
2. Grease contaminants are also fairly common in commercial installations, especially for restaurant applications. For this type of cleaning scenario, Duro-Last recommends a heavy duty cleaner like DeWitt’s Citrus Cleaner. Depending on the amount of grease present on the roof, a good amount of scrubbing will likely be needed. But the process is essentially the same, requiring only the cleaner, a hose and push broom.
3. If biological growth is present on the roof, Duro-Last offers Wash Safe Roof Wash specifically for this need. Simply mix a half cup of the Wash Safe Roof Wash cleaning powder for every gallon of water and let it activate for 15 minutes before spraying the roof using a pump sprayer, or other spraying method. Wash Safe Roof Wash is formulated to kill the biological growth so it can be cleared off with a hose, push broom or power washer. If using a power washer, it is imperative that the maximum pressure is set to 1000 psi with a fan tip, and the nozzle is kept at least 12 inches from the roof to prevent damage to the membrane.
4. Asphalt is typically the most difficult to clean as it stains the membrane even after cleaning. Duro-Last recommends Bulldog® Asphalt Remover for this type of contaminant; white wall or citrus cleaners will also work. Again, use a push broom and hose to scrub the rooftop and rinse the cleaning solution.
Finally, no matter what cleaning need presents itself, it’s important to remember that harsh solvent-based cleaners should never be used and acetone should only be used as a spot cleaner where a patch or strip will be welded over.
The Duro-Last Quality Assurance Department is available to answer your roof cleaning questions and can provide guidance based on your specific needs. Contact us at
800-248-0280 with all of your cleaning questions!