Commercial roofs accumulate biological growth, debris, and pollution staining that shortens membrane life and creates drainage problems. Algae and moss hold moisture against TPO and EPDM membranes, accelerating UV degradation. Debris blocks drains and scuppers, turning a flat roof into a pond after every storm.
We clean flat commercial roofs, metal roofs, and low-slope systems without walking crews across the membrane. Drone delivery means no foot traffic on a TPO or EPDM surface, no risk of puncture, and no warranty concerns from improper access. For metal roofs, soft washing removes biological growth without stripping coatings.
What biological growth does to a commercial roof membrane
TPO and EPDM membranes are designed to shed water, not to support biological growth. Algae and moss root into the surface and hold moisture against it continuously, which is the opposite of what the membrane is designed to do. The result is accelerated oxidation, micro-cracking, and premature failure.
A commercial roof replacement is a six-figure project on any building of meaningful size. Cleaning on a regular schedule is one of the cheapest ways to extend membrane life and push that capital expense further out.
What a clean roof gives you besides looks
Reflectivity. White TPO and PVC roofs are chosen partly because they reflect sunlight. Dirt cuts that reflectance over the first years of service. Cleaning brings much of it back, which lowers the cooling load on the building.
Warranty records. Several membrane manufacturers put maintenance and cleaning expectations in their warranty terms. A dated record of each cleaning, with the method and products used, supports a claim if you ever need to make one.
A close look at the membrane. The drone survey before cleaning covers the whole roof at close range. That is when open seams, failed pitch pockets, lifted flashing, punctures from HVAC service, and equipment leaking onto the membrane show up, and we note them for your roofer.
Commercial roof cleaning by membrane type
TPO and PVC single-ply: low pressure and a mild cleaner that the manufacturer approves. Never a strong solvent, which can attack the membrane, and never hard pressure at the seams.
EPDM rubber: some cleaning chemistry breaks EPDM down, so the choice of product is most of the decision.
Modified bitumen and built-up roofs with a granular cap: the granules protect the asphalt from UV, the same as on a shingle, and pressure strips them off.
Standing seam and metal panel: these take more, but the coating carries its own finish warranty, and alkaline products can stain or dull it.
Fewer people on the roof
Anyone working on a low-slope roof near an unprotected edge needs a fall-protection plan that meets OSHA rules. Foot traffic also damages roofs. Every trip across a membrane in the wrong shoes is a puncture risk.
Applying and rinsing from a drone means fewer people on the membrane, no rigging on steep mansard sections, and reach on walls where a lift cannot be set up. Read how drone cleaning works and our guide to winter prep for commercial exteriors.
Signs it's time to schedule
- Green or black biological growth on the membrane surface
- Moss clumps along parapet walls and HVAC curbs
- Debris accumulation at drains and scuppers
- Ponding water visible from upper floors of adjacent buildings
- Dark staining on metal roof panels
- Granule loss or chalking on modified bitumen surfaces
How we do it
Roof and drain assessment
Drone inspection of the full roof plane before any cleaning. Drain and scupper condition documented, debris load assessed.
Drain clearing
All drains and scuppers cleared of debris before washing begins so rinse water exits properly.
Soft wash application
Biodegradable cleaning solution applied at low pressure. No foot traffic on the membrane, no risk of puncture.
Rinse and drainage check
Full rinse and confirmation that all drains are flowing freely before we leave.
Where we work
WashLabs is based in Philadelphia and serves commercial properties across Pennsylvania, New Jersey, and Delaware. We travel for the right job — if you have a property outside our immediate area, reach out and we'll let you know if we can make it work.
Commercial Roof Cleaning questions
Will roof cleaning void my membrane warranty?
Soft washing at low pressure with biodegradable solution is the method most membrane manufacturers recommend. What voids warranties is foot traffic, high-pressure washing, and abrasive cleaning. We avoid all three.
Can you clean a roof without walking on it?
Yes. Drone delivery means no crew on the membrane surface. This is particularly important for TPO and EPDM roofs where foot traffic creates puncture risk.
How often should a commercial roof be cleaned?
Most commercial roofs in the Philadelphia region benefit from cleaning every 2–3 years. Roofs with heavy tree exposure or significant HVAC equipment that traps debris may need annual attention.
Do you clear roof drains?
Yes. Drain and scupper clearing is included in every roof cleaning visit. Blocked drainage is often the most urgent issue on a flat commercial roof.
Does roof cleaning help with energy costs?
It can. White TPO and PVC roofs are specified partly for how much sunlight they reflect. Dirt reduces that over the first years of service, and cleaning recovers a good part of it, which reduces the cooling load.
Where does the wash water go?
Roof wash water that carries cleaning agents generally may not go into a storm drain. Ask how it will be handled before the job is scheduled.