Soft washing removes dirt, algae, and mildew from siding without the high-pressure damage that traditional power washing causes. It's become the preferred method for most homeowners because it actually preserves your exterior rather than eroding it. Here's what you need to know before hiring someone to do it.
Why Soft Washing Beats Pressure Washing for Siding
Pressure washing can strip paint, gouge wood, crack stucco, and force water into walls where it causes rot. Soft washing uses lower pressure (typically 500 PSI or less) combined with biodegradable chemical solutions to safely kill and remove organic growth like algae, moss, and mildew.
The chemicals do the heavy lifting. Once applied, they break down the biological material, and a light rinse brings everything away. Your siding stays intact, and results typically last 2–3 years longer than pressure-washed surfaces because the root organisms are eliminated, not just blasted off.
What Soft Washing Actually Costs
Expect to pay between $0.10 and $0.25 per square foot for residential soft washing, though prices vary by region and siding type. A 2,500 sq ft home typically runs $250–$625 for the job. Some companies charge flat rates instead ($400–$1,500 depending on home size), while others quote by the hour ($75–$150/hr).
Factors that affect pricing:
- Siding material – Vinyl, fiber cement, and wood each require slightly different approaches
- Contamination level – Heavy algae or mildew coverage takes longer
- Home accessibility – Multi-story homes, steep terrain, or tight landscaping increase labor
- Regional market – Urban areas and coastal regions where algae thrives tend to cost more
Get three quotes before deciding. Most reputable soft washing contractors offer free estimates and can explain why their pricing differs.
How to Prepare Your Property
Before the crew arrives, take simple steps to protect your investment:
- Close all windows and doors securely
- Move potted plants, outdoor furniture, and grills away from the siding
- Cover air conditioning units, electrical panels, and outdoor outlets if they're near treatment areas
- Inform the contractor about delicate plants in landscaping beds—they'll protect them or avoid certain chemicals nearby
- If you have pets, keep them indoors during the service
Most jobs take 2–4 hours for an average home. Ask the contractor how long they estimate and whether they'll touch base when they're done.
What to Look for in a Soft Washing Contractor
Not all cleaning companies understand soft washing. Many will quote you for pressure washing because it's faster, even if it's wrong for your siding type. Hire someone who:
- Asks about your siding material and contamination type before quoting
- Uses EPA-approved, biodegradable chemicals suitable for residential use
- Carries liability insurance and is bonded
- Provides references from similar jobs (ideally homes with the same siding as yours)
- Offers a warranty on the work (typically 12–24 months)
- Explains their exact process and chemicals upfront
Request proof of insurance before they arrive. A legitimate contractor will have no problem providing it.
After Soft Washing: What to Expect
Your siding will look dramatically cleaner immediately after rinsing. However, some homeowners expect instant perfection on heavily stained wood or deep algae—that's unrealistic. One pass handles most contamination, but stubborn stains may require a second application weeks later.
Avoid power washing the siding yourself for at least a year after treatment. The chemicals continue working subtly, and aggressive washing will undo the work.
Finding Trusted Contractors in Your Area
Soft washing is specialty work, so don't just pick a generic house cleaner from the first search result. Platforms like Mercoly let you compare and find trusted soft washing providers in your area, read customer reviews specific to your region, and get multiple quotes from vetted contractors—all in one place.
Frequently Asked Questions
Q: Is soft washing safe for all siding types? Soft washing works on vinyl, fiber cement, wood, and stucco, but the chemical mix and pressure settings differ for each material. Always confirm your siding type with the contractor before they start.
Q: How long before results fade? Most soft-washed surfaces stay clean for 2–3 years, especially if your home is shaded or in a humid climate. Regular maintenance washing every 3 years keeps growth minimal.
Q: Can I soft wash my siding myself? You can rent equipment and buy chemicals, but improper dilution or application damages siding or doesn't kill the root organisms. Hire a professional for your first job—it costs less than fixing mistakes.
Start comparing quotes from soft washing contractors today to find the right fit for your home.