Professional Roof Moss and Algae Removal in Avondale, PA
Organic growth on roofing surfaces is one of the most underestimated threats to roofing system longevity. Homeowners often view moss-covered roofs as a minor cosmetic issue, but the actual impact on shingle performance and lifespan is substantial. DFW Roofing Inc provides professional moss, lichen, and algae removal services across Avondale, PA using techniques specifically designed to eliminate existing growth without causing the secondary damage that improper methods cause.
The critical distinction in professional moss removal is the difference between removing the visible symptom and eliminating the root structure. Moss and lichen both develop extensive root-like structures called rhizoids that penetrate into the shingle surface and between shingle layers. Simply brushing off visible surface growth leaves these root systems intact, allowing regrowth to appear within weeks. Effective professional treatment requires biocidal chemistry that kills the organism at the root level and then allows the dead material to be removed or wash off naturally over subsequent rainfall events.
"Most major asphalt shingle manufacturers including GAF, Owens Corning, and CertainTeed specify in their warranty terms that biological growth exceeding defined thresholds or cleaning methods that include high-pressure washing can void coverage. Professional low-pressure biocidal treatment is the only method that removes growth while preserving warranty compliance."
Understanding the Three Types of Roof Biological Growth
True plants with root-like structures that lift shingle edges and retain moisture continuously against the shingle surface. Most visible on north-facing slopes and shaded areas. Causes granule loss, edge lifting, and accelerated asphalt degradation.
A symbiotic organism combining algae and fungi that bonds tenaciously to roofing surfaces. Lichen is considerably more difficult to remove than moss and its root-like holdfasts can cause physical damage to shingle surfaces upon removal if not treated first with biocidal chemistry to loosen the bond.
Appears as dark streaking on roof surfaces, often mistaken for dirt or mold. A cyanobacterium that feeds on the limestone filler in asphalt shingles. The black coloring comes from a protective UV-shielding pigment the organism produces. Treated effectively with biocidal wash but requires preventive treatment to prevent rapid recurrence.
Our Moss Removal Process for Avondale, PA Roofs
Our technician inspects the full roof surface to document the extent and type of biological growth, assess any underlying shingle damage that may be exposed after treatment, identify contributing factors such as overhanging branches, and evaluate the roof's pitch, ventilation, and drainage characteristics that affect treatment approach.
Before any treatment application, we protect vegetation, lawn areas, and hardscape surfaces below the roofline that may be affected by treatment runoff. This includes pre-wetting soil and plants to dilute any contact with biocidal chemicals and covering sensitive plantings where necessary.
We apply our professional biocidal treatment formulation using low-pressure equipment that delivers even chemical coverage without the surface abrasion or granule displacement caused by high-pressure washing. The treatment penetrates growth colonies and kills organisms at the root level. Concentration and dwell time are adjusted based on growth type and density.
For heavy moss accumulations where treated growth will not naturally shed within an acceptable timeframe, we perform gentle manual removal using soft brushes following biocidal treatment. This step is only performed after the biocidal application has killed root systems, preventing the holdfast damage that occurs when live organisms are mechanically removed.
Following growth removal, we apply zinc or copper-based preventive treatment to roof surfaces and install zinc or copper strip at the ridge when appropriate. These metals leach slowly in rainfall, creating a roof environment that is inhospitable to moss and algae development for two to four years, depending on rainfall patterns and growth pressure in your specific location.
Why High-Pressure Washing Damages Asphalt Shingles
High-pressure washing is the most common improperly performed roof cleaning method and the one most likely to cause lasting damage. Asphalt shingles rely on their granule surface for UV protection, fire resistance, and aesthetic appearance. These granules are embedded in the asphalt surface but are not permanently bonded in a way that resists abrasive pressure from water delivered at high velocity. Pressure washing strips granules in direct proportion to the pressure used, effectively removing years of shingle lifespan in a single cleaning session.
Beyond granule loss, high-pressure washing drives water under shingle laps and into joints that are designed to shed water from above, not resist it from below. This can cause immediate infiltration at vulnerable points and long-term deterioration of the felts and deck substrate. Most asphalt shingle manufacturers explicitly state in warranty documents that high-pressure washing voids coverage. DFW Roofing Inc never uses high-pressure washing on shingle roofing surfaces for any purpose.