Roof cleaning in Houston, Texas, almost always means getting rid of algae. Those long dark stripes running down from the ridge are a living organism, and the humid Gulf Coast climate suits it perfectly. The fix that roofing manufacturers describe is gentle: a cleaning solution that kills the growth, followed by a low-pressure rinse. No blasting, no scrubbing.
Houston Power Washing Pro does not climb roofs or clean them. It is a free phone line. When you call (832) 662-4107, an automated assistant asks what you need cleaned and roughly how large the home is, then transfers you to an independent, owner-run local company that does soft wash roof cleaning. That company inspects the roof, gives you a price and is paid by you. If it is busy on another job, your details are passed along so it can call back.
Those streaks are algae, not dirt
The Asphalt Roofing Manufacturers Association (ARMA) and Owens Corning both identify the usual culprit as Gloeocapsa magma, a blue-green algae. It shows up as brown to black discoloration, and homeowners commonly assume it is soot, mildew or debris from the trees. It tends to start on the slopes that dry slowest, then spreads.
ARMA's guidance covers moss as well as algae, and moss is the thicker, greener growth that can take hold on the most shaded slopes. Either way, the goal of soft wash roof cleaning in Houston is the same: kill the growth without harming the shingles that sit under it.
What shingle makers say about pressure washing a roof
This is the single most useful thing to know before you hire anyone for roof cleaning in Houston, TX. Three of the biggest names in asphalt roofing say essentially the same thing.
- ARMA says algae can be lightened with a diluted chlorine-based solution applied and rinsed gently with low-pressure water, warns that scrubbing loosens granules, and says high-pressure washing is likely to damage asphalt roofing.
- GAF, in technical bulletin R-102, recommends a bleach-based wash with a low-pressure rinse and cautions that power washing can dislodge granules and shorten shingle life.
- Owens Corning advises against scrubbing and high-pressure power washing for the same reason: the granules shield the asphalt from the sun.
A company that plans to walk your roof with a pressure wand is ignoring the people who made your shingles.
Every roof material needs a slightly different approach
Asphalt shingles
The most common Houston roof. Soft washing only, with the solution doing the work and a garden-hose-strength rinse. Ask whether the company protects the gutters and downspout outlets so runoff does not pool on your beds.
Concrete and clay tile
Eagle Roofing, a concrete tile maker, favors water or a very mild cleaner that suits concrete and warns that some products can etch tile. Wet tile is slippery and breaks underfoot, so it recommends an experienced, insured roofing professional.
Metal panels
Metal Sales suggests mild detergent and low pressure, avoiding anything abrasive that scratches the coating, and checking the panel maker's warranty first because some specify which cleaners may be used.
What a careful soft wash roof cleaning includes
You are not expected to know the chemistry. What you can judge is whether the company describes a sensible process when it quotes. Listen for these points.
- A look at the roof before anything else. Lifted or cracked shingles, soft decking or missing flashing are roofing problems, and a responsible cleaner points them out instead of washing over them.
- Ground protection. Shrubs, flower beds and grass under the eaves are wetted down first and rinsed again later, since roof runoff lands right on them.
- Low-pressure application. The solution is sprayed on from a ladder, the edge or a safe position, never driven into the shingles with force.
- Clear expectations. A good company tells you up front what the roof should look like when it leaves and whether any staining may take longer to fade, so nobody is surprised.
- Gutters and walls rinsed. Runoff can mark the siding and gutter faces, so those get rinsed at the end.
- Call any hourAn automated assistant answers (832) 662-4107, day or night, and asks which service you need.
- Describe the jobSay what needs cleaning and roughly how big it is. A house, a driveway, a roof, a storefront.
- Get put throughYour call goes to an independent, owner-run local pressure washing company, which hears a short summary first.
- Deal with them directlyThat company inspects, quotes, does the work and is paid by you. If it is out on a job, it calls you back.
How this line works: Houston Power Washing Pro is a free phone line, not a pressure washing company. It connects you with an independent local pressure washing company, which inspects, quotes, does the work and is paid by you directly. Houston Power Washing Pro never charges callers. It may be paid a referral fee by the companies it connects callers with. How it works.
Why Houston roofs streak so quickly
Wet, warm air and long growing seasons are a recipe for algae. Then there is storm season: NOAA's Atlantic hurricane season runs June 1 through November 30 and peaks in September, and the heavy rain that comes with it keeps shaded slopes damp for days. Add the yearly spring pollen and a roof under trees rarely gets a dry week.
Wooded suburbs feel it most. Kingwood was branded "The Livable Forest" for its tree cover, Conroe sits beside Sam Houston National Forest and its roughly 163,000 acres of pine and hardwood, and Spring has thick loblolly pine along the Spring Creek Greenway. Needles collect in roof valleys, hold water and give algae a head start. If you live in Kingwood, Conroe or Spring, those pages cover local deed restrictions and conditions.
Is it a cleaning job or a roofing job?
A soft wash changes how a roof looks. It does not repair anything. Before you call about streaks, step back into the yard and look for signs that point to a roofer instead.
Usually a cleaning call
- Even black or brown stripes running downhill from the ridge
- Green or gray growth on the slope that gets the least sun
- Shingles that lie flat and look whole under the stain
Talk to a roofer first
- Curled, cracked or missing shingles after a storm
- Bare patches where the granules are gone
- Water stains on ceilings inside the house
The same phone number also handles roofing calls, so if the problem turns out to be more than algae, call back and choose roofing when the assistant asks.
Keeping the streaks from coming back
No cleaning lasts forever in this climate, but a few things stretch the time between visits.
- Trim overhanging branches. More sun and air on the shingles means they dry faster after rain.
- Keep valleys and gutters clear. Packed needles and leaves hold water where algae starts.
- Ask about zinc or copper strips. ARMA says zinc strips near the ridge may reduce regrowth, because rain carries metal ions down the slope. They are also worth considering when the roof is replaced.
- Look at algae-resistant shingles next time. Owens Corning and CertainTeed both make lines with copper-bearing granules meant to slow algae. Warranty terms vary by product, so read the details.
A roof cleaning is a good moment to have the gutters and siding done too, since runoff from the roof ends up on both. Mention everything when you call so the company can price it together.
Before you book
Ask the company three things: whether the roof will be soft washed with no high-pressure spray on the shingles, whether it carries liability insurance and can show proof, and whether the quote lists the roof separately from any gutter or house work. Price questions are covered in the roof cleaning cost guide, and the guide to getting a quote explains what belongs in writing. If you are curious about the terms, power washing vs pressure washing sorts them out.
Often booked with roof cleaning
Residential Pressure Washing
Driveways, walks, patios, pool decks and other hard surfaces around a Houston home, matched with a company that sizes the pressure to the surface.
House Washing and Soft Washing
Low-pressure soft washing for brick, fiber cement, vinyl and stucco, so green mildew and black streaks come off without forcing water behind the siding.
Gutter Cleaning and Brightening
The black tiger stripes on the outside of gutters and fascia, often handled together with a house wash.