Asphalt shingles are granular and layered, and a direct high-pressure spray can strip granules or lift shingle edges. Soft washing avoids that by relying on a cleaning solution to break down moss, algae and lichen at the root, with only a light rinse to clear it.
Low-pressure soft wash instead of a direct high-pressure spray that can lift or crack shingles.
Our solution breaks down growth on contact instead of just rinsing the surface layer.
Gutters and downspouts are kept clear so cleaning solution and debris don't pool where they shouldn't.
We check the roof's shingle condition and moss or algae coverage, then confirm a written price.
Soft washing avoids the granule loss and shingle lifting that a direct high-pressure spray can cause.
The cleaning solution dwells long enough to break down moss, algae and lichen, not just rinse the surface.
We rinse from a safe position rather than walking directly on fragile or steep sections wherever it can be avoided.
We work carefully around gutters, landscaping and anything below the roofline.
We check the roof's shingle condition and moss or algae coverage, then confirm a written price.
We apply a cleaning solution evenly across the slope and let it dwell to treat growth at the root.
We rinse from a safe working position, avoiding walking directly on fragile or steep sections.
We check the finished roof with you before we leave.
Capital Wash & Seal provides professional roof cleaning (soft washing) throughout Ottawa and the surrounding area. Asphalt shingle roofs often develop dark streaking, moss patches and algae growth, especially on shaded, north-facing slopes that stay damp longer after rain or snowmelt. Left alone, moss can work its way under shingle edges and hold moisture against the roof deck, while algae growth tends to spread across the whole slope over a few seasons. We clean shingle, metal and other common Ottawa roofing types with a low-pressure soft wash and a cleaning solution matched to the material, never a high-pressure spray that can lift or crack shingles.
Yes. Soft washing uses low pressure and a cleaning solution instead of a direct high-pressure spray, which is why it's the recommended method for asphalt shingle roofs rather than pressure washing.
Moss can return over time, especially on shaded, north-facing sections of roof that stay damp longer, but a proper soft wash removes existing growth at the root and slows regrowth compared to a surface rinse alone.
Yes, we adjust our solution and technique for metal roofing, which responds differently to cleaning chemistry than asphalt shingles.
We work from a safe position and avoid walking directly on fragile or steep shingle sections wherever possible, since foot traffic itself can damage a roof.
Roof soft washing typically runs $150 to $650 depending on roof size and how much moss or algae has built up, confirmed with a written quote before we start.
Soft washing is designed to avoid that. We use a low-pressure rinse and let the cleaning solution do the work of breaking down moss and algae, rather than blasting the shingles directly.
Yes, those streaks are usually algae, and our low-pressure soft wash treats the whole roof evenly, including the areas around vents and flashing where streaking tends to concentrate.