Roof soft wash vs pressure washing: which one your tile roof needs
Updated: 32 minutes ago
If someone quotes you to pressure wash your tile roof, get a second quote. High pressure on a South Florida roof is how tiles crack, how granules come off shingles, and how water gets under the underlayment. The job you want is a soft wash, and the difference is not marketing.
What the black streaks actually are
They are not dirt and they are not mold. They are gloeocapsa magma, a cyanobacteria that arrived in the humid Southeast decades ago and now lives on almost every roof in Broward and Miami-Dade. It feeds on the limestone filler used in shingles and on the porous surface of concrete tile, and it spreads downhill with every rain, which is why the streaks always run toward the gutters.
Because it is a living organism with a root structure, blasting the surface does not end it. You remove the visible layer and leave what regrows.
What high pressure does to a roof
A pressure washer at roof-cleaning range puts out enough force to strip paint off a fence. On concrete tile it erodes the surface coating that keeps the tile waterproof, and the tiles themselves crack under a technician's weight in ways you do not see until the next storm. On asphalt shingle it removes the granules that are the shingle's entire UV protection, which visibly shortens its life. It also drives water sideways under tiles and into the underlayment, and that damage shows up as a ceiling stain months later.
Most tile manufacturers void warranty coverage for pressure-washed roofs, and most Florida roofers will tell you the same thing without being asked.
What a soft wash is
Low pressure, about what a garden hose puts out, plus a cleaning solution that kills the organism at the root. The solution does the work instead of the force. We pre-soak and rinse the landscaping so nothing burns, apply, let it dwell, then rinse. The roof keeps looking clean for two to three times longer than a pressure-washed roof because there is nothing left alive to regrow.
This is also the method the asphalt shingle industry association recommends. It is not the cheap way or the fast way, it is the way that does not cost you a roof.
Where pressure does belong
Concrete driveways, pavers, sidewalks and pool decks. Those surfaces are hard, flat and not holding your house's weatherproofing together. We use real pressure there and soft wash everything else: roofs, painted stucco, siding, screen enclosures.
How to tell which one a company is selling you
Ask one question: what PSI do you use on the roof, and what is in the solution? A soft wash answer involves low pressure and a named cleaning agent. If the answer is a number in the thousands, or a shrug, keep calling. Also ask for proof of liability insurance, because a cracked tile is their problem only if they carry it.
How often, and what it costs
Every two to three years for most South Florida roofs, or sooner if you are under heavy tree cover. Our roof soft wash is $0.60 per square foot of roof area with a $550 minimum. We measure from aerial imagery, so you can get a real number without anyone climbing on your roof to quote it.
Text your address to 754-226-0066 and we will send a roof number the same day. Serving Fort Lauderdale, Pembroke Pines, Weston, Sunrise, Davie, Doral, Coral Gables and the rest of Broward and Miami-Dade.
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