Algae Removal
Black Streaks Erased
The dark streaks running down your roof are algae colonies feeding on the limestone in your shingles — ugly now, corrosive over years. Soft-wash removal clears them without harming a granule.
Your Shingles Are Being Eaten, Slowly
Gloeocapsa magma is an airborne algae that colonizes shingles and feeds on the crushed limestone filler inside them — the black streaking is millions of organisms with UV-protective dark sheaths, always worst on north slopes and shaded runs. Beyond curb appeal, mature colonies hold moisture and slowly degrade the surface. Soft-wash treatment kills the colony and the streaks fade with the weather — no pressure washing, which strips granules and voids warranties.
Why Streaks Come Back — And How They Don’t
Algae re-seeds from the air, so bare shingles in shade will streak again in years. Modern shingles fight back with copper-infused granules — algae-resistant lines carry long stain warranties — and zinc or copper strips at the ridge wash trace metal down the slope with every rain. If your roof is due for replacement anyway, choosing an algae-resistant shingle makes this a solved problem.
What Homeowners Ask Us About Roofs
Are the black streaks damaging or just ugly?
Both, slowly — the colonies hold moisture and consume filler minerals. Ugly arrives years before damage, which is why treatment now is cheap insurance.
Why is only one side of my roof streaked?
Algae favors slopes with less direct sun and slower drying — typically north-facing and tree-shaded runs. The streak-free south slope is getting free UV treatment daily.
Can I use bleach from a garden sprayer?
Homebrew mixes at wrong strengths kill lawns, corrode gutters and streak siding — and ladders plus wet roofs end badly. Soft washing exists because the chemistry and the safety both matter.
What causes black streaks on roof shingles?
Gloeocapsa magma algae feeding on the limestone filler in shingles — an organism, not dirt, which is why washing never fixes it.
Do algae-resistant shingles really work?
Copper-infused granule lines carry long stain warranties and genuinely resist recolonization — the permanent fix if a replacement is in your future anyway.
Will bleach damage my roof shingles?
Correct soft-wash dilutions are shingle-safe; homebrew strengths kill lawns, corrode metal and void warranties. The chemistry ratios are the whole job.
How long does roof algae treatment last?
Typically several years before recolonization shows — shaded north slopes recolonize fastest, and ridge metals stretch the interval.
Are roof black streaks bad for your health?
The algae lives outside and isn’t a health hazard indoors — the cost is curb appeal now and slow shingle degradation over years.
The Clean-Roof Set
Streaks, moss and the umbrella service.
Streaks Dragging The House Down?
Free photo quote — most streak jobs treated in one visit.