Roof Soft Washing in Morris & Passaic County, NJ

Never. High pressure blasts the protective granules off asphalt shingles, which shortens the life of the roof and voids most warranties. We soft wash instead: low pressure, shingle-safe detergents, and a gentle rinse.

Because that's the side that stays shaded and damp. Moss and lichen take hold where moisture lingers, and everywhere else the roof just collects dust, needles, and debris that hold moisture against the shingles.

Left long enough, yes. Moss works its way under the shingle edges and pries them apart, which turns a cleaning problem into a roofing bill. That's the main reason to deal with it before it spreads.

Eventually something will, since the shade and moisture that caused it are still there. But soft washing kills the growth at the source rather than knocking it off the surface, so it stays clean far longer than a rinse would manage.

We protect and pre-wet the plants, beds, and gutters below before we start, and we clear debris out of the valleys and gutter lines as part of the job. Then we walk it with you to confirm the result.

Roof soft washing in northern New Jersey generally runs $300 to $700. A single-story roof is usually $300 to $450 and a two-story $400 to $600, with steep pitches, multiple dormers and complicated rooflines at the upper end.

It costs more than a house wash because the work is slower, the access is harder, and everything below the drip line has to be protected and pre-wet before any solution goes on the shingles.

It is still a small fraction of a roof replacement, which is where unchecked moss and lichen eventually lead. Free estimates: 973-897-1757.

Those black streaks are algae. Specifically Gloeocapsa magma, a blue-green algae that feeds on the limestone filler in asphalt shingles. It is not dirt, it does not rinse off, and it does not stop spreading on its own.

Northern New Jersey is close to ideal for it: humid summers, heavy oak and maple canopy, and roof planes that stay shaded and damp for months at a time. It almost always starts on the north-facing pitch and works around from there, which is why one side of a roof can look years older than the other.

Left alone it holds moisture against the shingle and gradually loosens the granules that protect it from UV, so it shortens the life of the roof rather than just the look of it.

Not with a pressure washer. Moss and lichen grip asphalt shingles hard enough that blasting them off takes the protective granules with them, which shortens the life of the roof and voids most shingle warranties outright. Scraping and stiff brushing do the same damage, just more slowly.

The method every major shingle manufacturer endorses is soft washing: low pressure, a shingle-safe cleaning solution, and time. The growth dies at the root, releases its grip, and weathers away over the following few weeks rather than coming off in one visit.

Trimming back the limbs that overhang the affected pitch is the other half of the fix, since moss returns fastest where the roof never fully dries.

A properly soft-washed roof in this area typically stays clean for three to five years. It lasts that long because the treatment kills the algae at the root instead of knocking it off the surface, so regrowth starts from nothing rather than from what was left behind.

What shortens it is the same thing that caused it in the first place: heavy shade, limbs hanging directly over the roof, and a north-facing pitch that never fully dries. Homes under mature canopy in Kinnelon, Towaco and Bloomingdale sit at the shorter end of that range.