This property in Pahoa sits on a heavily vegetated lot with mature tropical trees and dense vegetation on multiple sides. The shade, constant moisture, and leaf debris that comes with that environment had allowed algae and mold to establish a firm grip across the entire corrugated metal roof. This was a multi-plane roof with hip intersections, and the biological growth was consistent across every surface, including the ridge cap and eave edges.
The before photos show a roof that had gone well past the point where rain would clear it on its own. The algae growth had turned the full corrugated surface from its original light gray to near-black across most of the roof.
Specific conditions visible before the job:
In Pahoa’s climate, algae and mold on a metal roof is not just a cosmetic problem. The biological layer holds moisture against the surface, which accelerates oxidation of the metal underneath over time.
The roof required a soft wash approach rather than high-pressure washing. Corrugated metal in this condition with heavy biological growth is best treated with a chemical application that kills the algae at the root level before rinsing. Running high-pressure water across a roof covered in this much algae moves it around the surface and forces it into seams and fastener holes without actually eliminating it.
A soft wash solution was applied across the full roof surface and allowed to dwell and break down the biological matter. The in-progress photos show the treatment in action, with the cleaning solution foaming as it works into the algae on the dark panels before rinsing. All roof planes were treated, including the hip sections, ridge cap, and the lower eave areas where debris had collected.
Once the soft wash treatment had done its work, the surface was rinsed using controlled pressure washing to clear the loosened algae and residue from the corrugations and carry it off the roof cleanly. The multiple hip intersections required attention to ensure all the valleys and angles were fully treated and rinsed.
The after photos show the full contrast with the before condition. Every plane of the roof came back to a consistent light gray, with the original corrugated surface visible and clear of biological growth from ridge to eave.
Results across the roof:
If your corrugated metal roof in Pahoa has gone dark from algae or mold, cleaning it at this stage is the right call before the biological layer has time to work on the metal surface underneath. A roof that looks like these before photos can typically be restored to its original condition in a single cleaning visit. Waiting longer means the algae has more time to hold moisture against the metal, and the window for a straightforward cleaning job gets smaller.
Property Wash in Paradise handles corrugated metal roof washing throughout Pahoa, Keaau, Hilo, and East Hawaii. We work on all roof types and sizes and use the right cleaning method for each surface condition. Contact us to get a quote for your property.
Learn more about what the process involves on our roof washing service page.
Or call us directly: 808-825-6280
