If you’ve noticed dark streaks on your roof or a greenish tint spreading across your siding, that’s not dirt. It’s algae, moss, or bacteria that can damage your home’s exterior over time.
Soft wash roof cleaning and siding cleaning are the most effective ways to remove it. Here’s what the process involves, why it matters, and what to expect.
What Is Soft Washing
Soft washing is a low-pressure exterior cleaning method that uses a biodegradable solution to kill and remove organic growth like algae, moss, mold, mildew, and bacteria from roofs, siding, and other exterior surfaces.
The cleaning solution does the work, not the water pressure. That distinction matters. High-pressure washing can crack or loosen shingles, strip caulking, and force water behind siding. Soft washing cleans thoroughly without putting your materials at risk.
According to the Asphalt Roofing Manufacturers Association (ARMA), the dark staining commonly seen on roofs is typically caused by Gloeocapsa magma, a blue-green algae. ARMA recommends low-pressure washing with an appropriate cleaning solution for safe roof algae removal, not pressure washing.
The Benefits of Soft Washing Your Roof and Siding
1. It restores your home’s appearance
Algae, moss, and dark streaking build up gradually. Sometimes it’s hard to remember what your roof and siding looked like clean. Soft washing removes years of discoloration and restores your home’s exterior without repainting or replacing materials. It’s one of the fastest exterior upgrades you can make without replacing anything.
2. It protects your roof’s lifespan
Algae, moss, and bacteria degrade roofing materials over time. Moss holds moisture against shingles, accelerating wear and contributing to premature breakdown. Catching it early is a lot cheaper than replacing a roof ahead of schedule.
3. It protects your warranty
Many roofing manufacturers recommend regular maintenance and removal of algae and biological growth as part of preserving roof performance and warranty coverage. Always review your specific warranty requirements. Pressure washing can void that coverage. Soft washing keeps you in compliance.
4. It reduces heat buildup in your home
Stained roofs are darker, and darker surfaces absorb more heat. That heat accumulates in your attic and raises the temperature inside your home. Removing algae buildup may help reduce excess heat gain in the roof system during warmer months.
5. It’s safe for your home and yard
Surrounding plants, walkways, gutters, fascia, and siding are rinsed before, during, and after the cleaning. The biodegradable solution won’t damage landscaping or leave residue on surfaces you didn’t intend to treat.
Why Soft Washing Works Better on Roofs and Siding
When it comes to soft washing vs pressure washing, not all exterior cleaning methods are built for roofs and siding.
High-pressure cleaning can damage shingles, push water into gaps, and strip surface coatings. Plus, it doesn’t actually kill the organisms causing the staining. The buildup comes back faster because the source was never treated.
Soft washing works differently. The cleaning solution eliminates algae and bacteria at the root, so results last longer and you’re not dealing with the same problem again by next season.
Learn more about soft washing vs pressure washing. 
What Our Process Looks Like
Our technicians apply a biodegradable cleaning solution designed to eliminate algae, moss, and bacteria at the source. Our cleaning solution does the work so there’s no need for aggressive pressure that can damage roofing or siding materials.
The service covers:
- Roof soft washing (shingles, flashing, ridgeline)
- Siding soft washing
- Rinse of gutters, fascia, and surrounding landscaping throughout the process
Signs Your Roof or Siding Needs Soft Washing
Here’s what to look for:
- Black streaks on shingles
- Algae on siding or discoloration spreading from the roofline
- Green patches on siding
- Moss growth along roof edges
- Areas that stay damp after rain
Late spring through summer is the best window for soft washing. Warm, humid conditions are when algae and moss grow fastest.
If you’re seeing staining, moss, or green patches on your roof or siding, get a free quote for roof cleaning or siding cleaning service from Ned’s Power Washing.
