Flat roof cleaning in Austin, TX

Live Oak Exterior Cleaning cleans flat and low-slope roofs across Austin and Central Texas, including the white membrane roofs on modern homes. The method is a soft wash: low pressure, the correct cleaning solution for the surface, and a clean rinse. The pressure stays far below the ceiling the membrane manufacturers publish, which is what keeps the work off the seams.

Because something on it is staying wet. Algae needs moisture and shade, and a flat roof gives it both wherever water sits after rain, wherever a wall or a parapet throws shade for most of the day, and anywhere the drainage is slow. Austin's humidity does the rest. It usually shows up first along a wall or in a low spot rather than across the whole roof.

Usually not. On most flat roofs the growth is in the damp and shaded sections rather than everywhere, so the honest answer is that we clean the areas that have gone green and leave the rest alone. We would rather look at the roof and tell you what it actually needs than sell you the whole surface because it is easier to quote.

With a soft wash, the same way we clean a shingle roof. Low pressure, the correct cleaning solution for the surface, and a clean rinse. The chemistry kills the growth at the root and the water only carries it away. Blasting it off with pressure removes what you can see and leaves what grows back, which is why the growth returns within a season when a roof is cleaned that way.

Not at the pressures a soft wash uses. The risk on a flat roof is pressure, not water: the seams, the fastener plates and the flashings around a drain or a pipe are what keep the roof watertight, and a hard stream aimed at one of them is what starts a leak. Carlisle, one of the larger membrane manufacturers, publishes a ceiling of 2,000 psi for cleaning its membrane. A soft wash sits far below that.

Everything below the work area is watered down before any solution is applied, and rinsed afterward. Pre-wetting is what keeps the solution from concentrating on a plant, and it is standard on every job we take rather than something we do on request.

On a house built in the last twenty years with a flat or low-slope section, it is most often TPO, thermoplastic polyolefin, which is the white single-ply membrane you can see seams and round fastener plates in. Modified bitumen and standing seam metal are the other two we see. We clean all three, matched to the material rather than cleaned the same way.