Commercial Roof Soft Washing: Why Regular Cleaning Protects Your Roofing Investment
Commercial roofs represent one of the largest capital investments in any building — and one of the most neglected maintenance items. Biological growth accumulates on commercial roofing systems just as it does on residential roofs, but the consequences are more significant: degraded roofing membranes, reduced energy efficiency from compromised reflective surfaces, and maintenance costs that compound when problems go unaddressed.
Regular commercial roof soft washing is a cost-effective component of any comprehensive building maintenance program. Here is what it involves, which roof types benefit most, and why the method matters.
What Grows on Commercial Roofs
- Algae — the most common growth on commercial roofs, presenting as green or black discoloration across the roof surface
- Moss — thicker growth that physically lifts roofing material and retains moisture
- Lichen — extremely adhesive combination of algae and fungi that bonds directly to roofing surfaces
- Mold and mildew — biological growth in areas with standing water or poor drainage
- Organic debris — leaves, bird droppings, and organic matter that create localized growing conditions
On flat or low-slope commercial roofs — the most common commercial roof type — standing water and poor drainage exacerbate all of these conditions.
How Biological Growth Damages Commercial Roofing Systems
EPDM and TPO Membrane Roofs
Single-ply membrane roofing (EPDM, TPO, PVC) is sensitive to biological growth in two ways. First, algae and lichen produce acids that degrade the membrane over time, causing brittleness and loss of flexibility. Second, biological growth holds moisture against the membrane surface, accelerating degradation at seams and flashings.
For white TPO and PVC membranes designed for solar reflectivity, algae accumulation dramatically reduces reflective performance — which translates directly into higher cooling costs.
Modified Bitumen and Built-Up Roofing
Modified bitumen and built-up roofing systems are somewhat more resilient to biological growth than single-ply membranes, but they are not immune. Algae and moss growth on granulated modified bitumen surfaces work into the granule layer over time, accelerating weathering. Standing water beneath biological growth concentrations puts pressure on membrane seams.
Metal Roofing
Commercial metal roofs develop algae in textured or corrugated surface areas and along seam lines. While metal itself is not degraded by algae, the appearance deterioration is significant. Some metal coatings can also be affected by the acids produced by biological growth.
Why Soft Washing Is the Right Method for Commercial Roofs
High-pressure washing on commercial roofing creates new problems while solving old ones. High PSI can damage membrane seams and flashings, dislodge granules on modified bitumen, and force water under raised roofing components. It also does not address the root cause — it blasts surface growth without killing the organism, resulting in rapid regrowth.
Soft washing applies professional-grade biocidal solutions at low pressure, killing biological growth at the cellular level and removing the organic matter causing discoloration. All Clean technicians are OSHA-certified in chemical handling, which is particularly important for commercial applications where the volume of cleaning chemistry used is significantly larger.
Protecting Reflective Roof Coatings
Many commercial flat roofs have reflective white coatings (elastomeric or silicone) applied specifically to reduce heat absorption and lower cooling costs. These coatings lose significant reflective effectiveness as algae accumulates. Regular soft washing restores reflective performance — which has a direct, measurable impact on energy costs.
Building a Commercial Roof Maintenance Program
A reactive approach to commercial roof maintenance costs more in the long run. A scheduled maintenance program addresses biological growth before it reaches the point where it causes structural damage or requires professional remediation.
For most commercial roofs in Upstate New York, a biannual cleaning schedule (spring and fall) is appropriate. Buildings with significant shade coverage, persistent moisture issues, or north-facing roof sections may benefit from more frequent attention. All Clean provides commercial maintenance programs for building owners, property managers, and facilities teams who need predictable scheduling and documentation of completed work.
What to Expect from a Commercial Roof Soft Wash
The process involves a pre-treatment inspection to identify drainage issues, membrane condition, and any areas requiring special care. Cleaning solution is applied at low pressure, allowed to dwell for appropriate contact time, and thoroughly rinsed. Downspouts and drains are checked and cleared as part of the service. For larger commercial properties, we provide documentation of the cleaning scope, surfaces treated, and maintenance observations — useful for building maintenance records and insurance documentation.
Frequently Asked Questions
No — soft washing at appropriate pressure settings and with solutions designed for roofing applications is safe for all major commercial membrane types including TPO, EPDM, and PVC. Regular soft washing actually extends membrane life by removing the biological growth that accelerates membrane degradation.
Biannual cleaning (spring and fall) is the standard recommendation for most commercial roofs. Buildings with flat roofs and drainage issues, heavy surrounding tree coverage, or white reflective membranes that need to maintain energy performance may benefit from more frequent cleaning.
Yes. Commercial roof soft washing is performed from the roof surface and does not require access to the building interior. We work with property managers to schedule service during low-impact times and can phase the cleaning across multiple days for large commercial properties if needed.
Yes. White and light-colored reflective roofing membranes lose significant solar reflectivity as algae accumulates. Studies have shown algae-covered white membranes can reflect as little as 20 to 30 percent of their original capacity. Cleaning restores reflective performance and reduces cooling load.
Yes. We provide service documentation for commercial cleaning jobs including the date of service, areas cleaned, and any maintenance observations noted during the work. This documentation supports building maintenance records and can be useful for insurance and warranty purposes.
All All Clean technicians are OSHA-certified in chemical handling and application. For commercial roof work, this covers chemical selection and dilution, PPE requirements, and protocols for working at height and protecting surrounding property and drainage systems.
All Clean Power Wash provides commercial roof soft washing for office buildings, retail properties, industrial facilities, apartment complexes, and all commercial property types across Upstate New York. Contact us to discuss a maintenance program for your property.
