What soft washing is
Soft washing applies a cleaning solution to the roof at low pressure and lets the solution do the work, instead of blasting the growth off with force. On asphalt shingles that matters, because high pressure can strip the protective granules. OSU Extension cautions that improper pressure washing can damage shingles.
Soft wash versus pressure washing
| Soft wash | Pressure washing | |
|---|---|---|
| Pressure | Low, similar to a garden hose | High |
| How it cleans | Solution kills the growth, then it rinses off | Force removes it |
| Risk to shingles | Lower | Can strip granules or lift shingles |
| Best for | Asphalt shingle, cedar, tile roofs | Driveways, concrete, hard surfaces |
What a good soft wash includes
- Moss brushed or blown off first where it is thick
- Solution applied evenly across the roof, then rinsed
- Plants, windows and gutters protected, with a plan for runoff
- Gutters and downspouts cleared if you want them included
Ask what is in the solution. Many soft wash products are bleach-based. Ask which product will be used, how plants and runoff are protected, and whether the company holds any licenses that apply.
Cost
HomeAdvisor lists a Salem average of about $420 for roof cleaning, with a typical range of $290 to $573. See the cost guide.
Does it last?
Soft washing cleans what is there. It does not stop regrowth where the roof stays shaded and damp. Trimming back trees and a preventive step help. See prevention.
Want it done? Fill in the form below and a Salem-area company will quote it.