What Is Soft Wash Roof Cleaning? A Safer Way to Clean Your Roof
A roof cleaning method that uses professional cleaning solutions and low-pressure application rather than high-pressure water to remove organic growth and stains.
If you’ve noticed dark streaks, green growth, moss, or discoloration on your roof, you may assume it’s time to break out the pressure washer.
It’s actually one of the last things you want to do.
Roof shingles, especially asphalt shingles, can be damaged by the high pressure used for traditional power washing. The Asphalt Roofing Manufacturers Association (ARMA) specifically recommends against using a power washer or brushes to clean algae from asphalt roofing because the pressure and friction can loosen and remove the protective granules on the shingles.
That’s where soft wash roof cleaning comes in.
What Is Soft Wash Roof Cleaning?
Soft washing is a roof cleaning method that uses professional cleaning solutions and low-pressure application rather than high-pressure water to remove organic growth and stains.
Instead of trying to blast algae, moss, dirt, and other buildup off the roof, a cleaning solution is applied to the affected areas and allowed to do the work.
The result? A cleaner roof without the unnecessary force of high-pressure washing.
For asphalt shingles, ARMA recommends using an appropriate diluted cleaning solution, allowing it to work, and then gently rinsing the roof with low-pressure water.
Why Shouldn’t You Pressure Wash Your Roof?
Your roof isn’t the same as a driveway or concrete patio.
A pressure washer can be great for hard surfaces, but asphalt shingles are made up of layers and have protective granules embedded in their surface. High-pressure cleaning can loosen those granules and potentially damage the shingles.
ARMA states plainly that high-pressure washing should not be used to clean asphalt roofing.
Pressure washing your roof can also:
- Damage or loosen shingles
- Remove protective granules
- Drive water where it shouldn’t go
- Create unnecessary wear on an already aging roof
- Make an already slippery roof even more dangerous to work on
In other words, more pressure doesn’t mean a better roof cleaning.
What Are Those Black Streaks on Your Roof?
Those dark streaks aren’t necessarily dirt.
In many cases, they’re caused by blue-green algae, a type of cyanobacteria commonly found on roofs throughout North America. The organism can create dark brown or black discoloration as it grows across the roof.
Algae is especially noticeable on lighter-colored shingles and can make an otherwise healthy roof look old, dirty, or neglected.
Moss and lichen are different from algae and can present additional concerns. Moss can interfere with water shedding and hold moisture and debris against the roof surface.
So if your roof has suddenly developed dark streaks or green growth, don’t automatically assume you need a new roof.
It may simply need professional cleaning.
How Does Soft Wash Roof Cleaning Work?
While the exact process can vary depending on the roof material and condition, professional roof cleaning generally involves several steps.
1. Inspect the Roof
Before cleaning, the roof should be evaluated for its condition, material, existing damage, and the type of buildup present.
Not every roof should be cleaned the same way.
2. Protect Surrounding Areas
Professional roof cleaning requires more than spraying the roof.
Landscaping, siding, windows, gutters, and other surrounding areas should be considered and protected during the cleaning process.
3. Apply a Cleaning Solution
A properly selected cleaning solution is applied to the roof at low pressure.
The goal isn’t to blast the growth away. **The solution does the heavy lifting.**
4. Allow the Solution to Work
The cleaning solution needs time to break down and treat the organic growth and discoloration.
5. Gently Rinse
Once the treatment has had time to work, the roof can be gently rinsed using low-pressure water rather than aggressively pressure washed.
This approach is consistent with ARMA’s guidance for cleaning asphalt shingles.
Does Soft Washing Damage Shingles?
When the correct cleaning method, solution, and application are used for the specific roofing material, soft washing is designed to clean the roof without the damaging force of high-pressure washing.
However, that doesn’t mean every chemical or cleaning method is appropriate for every roof.
Roof manufacturers can have specific cleaning recommendations, and ARMA advises homeowners to consult the roofing manufacturer before using cleaning chemicals.
That’s one reason professional roof cleaning is important.
How Often Should You Have Your Roof Cleaned?
There isn’t a one-size-fits-all schedule.
The amount of shade, moisture, tree coverage, roof orientation, surrounding vegetation, and roofing material can all affect how quickly algae and other organic growth return.
Keeping gutters clear, removing roof debris, and trimming branches that create excessive shade can help reduce the moisture and debris that encourage algae and moss growth.
If you start noticing:
Black or brown streaks
Green patches
Moss
Lichen
Heavy debris
A roof that looks significantly darker or dirtier than it used to
…it may be time to have your roof evaluated.
Soft Wash Roof Cleaning in St. Louis
St. Louis homes deal with plenty of moisture, humidity, shade, trees, and seasonal weather—all conditions that can contribute to algae and organic growth on roofing surfaces.
If your roof is looking more green and grimy than clean and crisp, don’t reach for the pressure washer.
A professional soft wash can help restore your roof’s appearance while using a cleaning approach designed specifically for delicate roofing surfaces.
Don’t Blast It. Soft Wash It.
Your roof protects your entire home. It deserves a cleaning method that treats it that way.
PowerWash Pros STL provides professional exterior cleaning services designed to safely and effectively clean your home including roofs, siding, decks, driveways, and more.
If your roof is showing signs of algae, moss, or discoloration, contact PowerWash Pros STL for a professional roof cleaning evaluation.
Your roof doesn’t need more pressure. It needs the right approach.