Soft wash the roof and the walls; pressure wash bare concrete. Roofs, siding, brick walls, stucco, and painted trim get low pressure and a cleaning solution that kills growth at the root. Poured concrete driveways, sidewalks, and patios can take the pressure, and pavers and natural stone get a gentler, lower-pressure version.
What's the difference between soft washing and pressure washing?
Soft washing cleans with a solution that does the work at low pressure, while pressure washing cleans with the force of the water itself. A soft wash goes on at low pressure, more like steady rain than a pressure washer, sits long enough to kill algae, mold, mildew, and lichen, and is then rinsed off gently. A pressure washer shoots a tight, high-pressure stream that blasts dirt and stains off whatever it hits.
That's the whole trade-off. Pressure is great at removing surface grime from tough surfaces, but it doesn't kill anything living, and on softer materials it removes more than dirt. A soft wash is slower to set up, but it treats the growth that causes the staining instead of just stripping the color off the top.
| Soft washing | Pressure washing | |
|---|---|---|
| What does the cleaning | A cleaning solution, given time to dwell | The force of the water |
| Pressure | Low, more like steady rain | High |
| What it removes best | Algae, mold, mildew, lichen, and the black streaks they cause | Ground-in dirt, grime, and film on hard concrete |
| Where we use it | Roofs, siding, brick, stucco, stone, painted wood, gutter faces | Poured concrete driveways, sidewalks, patios, and pool decks |
Which surfaces get soft washed, and which get pressure washed?
Roofs and walls get soft washed; bare concrete gets pressure washed; pavers and natural stone sit in between, with low pressure and detergent. Tap a surface below to see which method it gets at Casa Care and why.
Which method does this surface need?
Pick a surface around your home.
Choose a surface to see the method.
Is it safe to pressure wash a roof?
No. Pressure washing strips the protective granules off asphalt shingles and can force water up underneath them, so we never put a pressure washer on a roof. This isn't just our house rule. The Asphalt Roofing Manufacturers Association (ARMA), the trade group for asphalt roofing manufacturers, says plainly that high-pressure washing systems are likely to damage asphalt roofing and shouldn't be used to remove algae or anything else. ARMA also warns against scrubbing, because the friction loosens granules, and describes gently applying a cleaning solution and rinsing it off by gently spraying the roof with water.
Those granules are the roof's sunscreen. Once they're gone, the asphalt underneath is exposed to Austin's UV and heat, and no cleaning can put them back. That's why every roof we clean, from composition shingle to clay tile and standing-seam metal, gets a low-pressure soft wash.
A wet, treated roof is slippery, and ARMA recommends that only trained professionals work on roofs. And a pressure washer is the one tool ARMA says never to use on asphalt shingles.
Does roof cleaning void a shingle warranty?
Pressure washing is the cleaning method most likely to cause shingle damage, and it can put a manufacturer's warranty at risk. ARMA, the asphalt roofing manufacturers' trade group, says never to use a power washer on asphalt shingles and describes a gentle application and a gentle rinse instead. Our roof cleaning is a low-pressure soft wash, and a pressure washer never touches the roof. Warranty terms are set by each shingle manufacturer, not by the company cleaning the roof, so if you're unsure what yours allows, check the warranty document or ask the manufacturer. We're happy to walk you through our method before you book.
Is soft washing safe for siding, brick, and stucco?
Yes. Soft washing is the right method for every common Austin exterior, including vinyl, HardiePlank, brick, stucco, natural stone, and painted wood. What changes from one material to the next is the detergent mix, the dwell time, and how gently we rinse.
Pressure is what causes the damage on walls. It can gouge stucco, chip paint, crack old caulk, and push water behind siding. It also only rinses the visible green off, so the growth comes back fast. A soft-wash house washing kills the mold, mildew, and algae at the root and covers the eaves, soffits, fascia, gutter faces, and downspouts in the same visit.
Mixed exteriors are common here, like a stone front with Hardie sides or brick below and siding above, so we adjust as we work around the house instead of using one setting for everything.
Walk around the house on a sunny afternoon. Green or black film low on the north wall, gray mildew under deep eaves, and rusty streaks below live oaks are all signs a soft wash is due. Sunny south and west walls mostly collect dust.
Which surfaces should be pressure washed?
Poured concrete: driveways, sidewalks, patios, garage floors, and pool decks. Bare concrete is hard enough to take pressure, and it's where ground-in dirt, tire film, and leaf stains build up. We clean it with commercial surface cleaners and biodegradable detergents.
Not all flatwork is the same, though. Stamped, colored, and sealed concrete gets lower pressure so the finish stays intact. Pavers, brick pavers, and natural stone like flagstone are cleaned at low pressure with detergent, because high pressure can blow the joint sand out of pavers and wear down the stone's surface. Our driveway cleaning and concrete cleaning pages cover oil drips, oak tannin stains, and what each surface can handle.
Why do black streaks come back after rain?
Because the streaks are a living algae, and neither rain nor a plain rinse kills it. On shingle roofs, those dark streaks are usually Gloeocapsa magma, which ARMA calls probably the most common of the algae behind roof discoloration. Its spores travel through the air, and it collects and grows on roofs and other outdoor surfaces. As our roof cleaning page explains, on asphalt shingles it feeds on the limestone filler in the shingle itself.
That's why a hose, or a pressure washer, doesn't fix it. A rinse doesn't touch the living algae underneath, and the moisture only helps it grow. ARMA notes that roof algae is most widespread in the Gulf States and in warm, humid conditions, which describes a Central Texas summer well. In Austin, the worst slopes are usually the north-facing ones and anything under live oak shade, where the roof stays damp longest.
Does soft washing last longer than pressure washing?
On roofs and walls, yes, because a soft wash kills the growth instead of just knocking the top layer off. A pressure-washed wall can look clean on the day and turn green again within weeks, because the roots of the growth are still there. A soft wash is given dwell time to kill algae, moss, mildew, and lichen down to the root, so it takes much longer to come back.
It isn't permanent. Spores keep landing on every roof and wall, and ARMA itself notes that algae discoloration can recur. Shade, humidity, and nearby trees decide how fast, which is why the schedule below varies from one home to the next.
How often should each surface be cleaned in Austin?
Roofs every two to three years, house washing about once a year, and driveways and other concrete about once a year, with shaded homes needing each one sooner. Here's how it breaks down:
| Surface | Most Austin-area homes | Shaded, north-facing, or under heavy oak canopy |
|---|---|---|
| Roof | Every 2 to 3 years | Sooner, based on what we see on the roof |
| House wash | Once a year | Often twice a year |
| Driveway | Once a year | Often twice a year |
| Patios, walks, and pool decks | Once a year | Sooner in shaded, damp corners. |
A quick rule of thumb: clean the roof when the streaks first show, not after moss moves in. An early cleaning is quicker and leaves the shingle surface in better shape.
Is soft washing safe for plants and landscaping?
We protect your landscaping on every soft wash: plants, beds, and lawn are pre-wet before any detergent goes on, covered where needed, and rinsed again when we finish. Leaves that are already soaked with water absorb less of anything that drips on them. We use biodegradable detergents and keep the pressure low from start to finish.
If you have delicate plants, a koi pond, or a vegetable bed right under the roofline, tell us when you book so we can plan around it.
Can I get my roof, house, and driveway cleaned in one visit?
Yes. Roof soft washing, house washing, gutter cleaning, driveway and concrete cleaning, and window cleaning can be bundled into one visit on request. We work from the top down: roof first, then gutters, then the house, then the concrete, and windows last, so rinse water only ever lands on surfaces that haven't been cleaned yet. Our guide to the right exterior cleaning order explains each step.
If you want it on a schedule, ask about our maintenance plans. List every surface you want cleaned when you request your quote, and we'll match the method to each one.
Ready to get the right clean for each surface?
Casa Care Window Cleaning soft washes roofs and homes and pressure washes concrete across Austin, West Lake Hills, Rollingwood, Lakeway, Bee Cave, Pflugerville, Cedar Park, and Round Rock. Get your instant quote in about 60 seconds, or call or text (512) 522-4985. We're open 24/7.