ROOF CLEANING

Have you noticed gross-looking black stains on your shingle roofing? That’s most likely algae! Obviously, it’s unsightly, but algae growth can also dramatically decrease the life expectancy of your roof.

Algae will gradually eat away at the limestone holding granules on your shingle, removing the first line of defense against the sun’s harmful UV rays. Did you know that algae growth can take 5-10 years off of the life expectancy of your roof shingles?

Safe & Effective Removal: Algae, Lichen & Moss

We offer a simple roof washing service to kill the algae and ensure your roof lasts for years. Don’t worry, we won’t blast your roof with high-pressure water that can similarly reduce your roof’s lifespan. Our expert cleaners will use just enough pressure (MAX 300 PSI) to make sure we can reach every area of your roof, stepping foot on your roof if need be. Our cleaning chemicals are highly effective, safe for your plants, and takes away the need for high-pressure washing. Once we treat the roof, 95%-100% of all the algae will disappear.

Roof Algae

Black or dark streaks on your roof are most likely a condition known as “roof algae.” Roof algae is actually caused by gloeocapsa magma, a cyanobacterium that’s a photosynthesizing bacterium, not a true alga (which have nuclei). Because it looks like algae and is found in similar environments, it’s often called “blue-green algae” or “roof algae.”

Roof algae produces a dark sheath to protect itself from damaging UV rays. Small discolored spots quickly become streaks on your roof that can turn a light-colored roof dark brown or black. By the time you can see it, it’s probably been there several months or longer.

Roof algae eat the shingles’ limestone filler, which gives the shingles weight. The surface granules, which provide the shingles’ UV protection, then begin to come loose and wash off during rainstorms. The shingles then absorb more heat and become hotter than they should, reducing the shingles’ life and increasing the heat in your attic—along with your cooling bills. Algae is especially damaging to the effectiveness of highly reflective asphalt shingles.

Houston’s humidity encourages algae growth on roofs. Algae can quickly spread from roof to roof via wind or animal, often affecting an entire neighborhood.

Mosses & Lichens

Irregular green splotches on your roof are either moss or a lichen. Both thrive in Houston’s humidity.

Mosses are soft plants that obtain moisture via their leaves. They prefer damp environments: north-facing roof planes (in North America) or roofs shaded by trees.

Mosses anchor themselves to the roof by driving their rhizoids (similar to roots), into shingles. As mosses grow, they can expose shingle edges and fracture shingles. Eventually they build a layer of soil by catching windblown dirt in their roots and stems. This soil facilitates algae and lichen growth, and even the growth of plants with real roots.

Lichens form when a fungus joins the roof algae (cyanobacteria). They attach themselves very securely to shingles via their fungal filaments (roots), which can penetrate shingles and the roof deck. This can lead to cracks, rot, and mold growth. 

The invasive roots of both lichens and moss cause shingle damage that only gets worse over time. Their roots also loosen the shingle granules that protect the asphalt and base materials from UV radiation and weather, which shortens the shingles’ life. Physically removing them would cause additional damage. But both can be killed via our soft wash.