Charleston's humid climate and salt-air exposure mean homes accumulate mold, mildew, algae, and grime faster than in drier climates. Pressure washing is one of the most cost-effective maintenance tasks you can do — but a bad job can crack wood siding, force water under shingles, or strip paint from surfaces that weren't ready.
Before you book anyone, check these five things.
1. Verify They Carry Liability Insurance
Pressure washers operate at 2,000–4,000 PSI. That's enough to crack brick mortar, shatter windows, or strip paint. If an uninsured operator damages your siding or breaks a window, the repair cost comes out of your pocket.
What to ask: "Can you send me a certificate of insurance?" Any legitimate company can provide one in minutes. If they hesitate or give excuses, walk away.
2. Understand the Difference Between Pressure Washing and Soft Washing
These are not the same thing, and using the wrong method on the wrong surface causes real damage.
| Surface | Right Method | Why |
|---|---|---|
| Driveways, concrete | Pressure washing | Can handle high PSI without damage |
| Vinyl / wood siding | Soft washing | High pressure forces water under panels, causes rot |
| Roofs | Soft washing only | High pressure removes protective granules from shingles |
| Deck wood | Low-pressure + appropriate cleaner | High pressure raises wood grain, causes splintering |
| Brick / pavers | Medium pressure | Mortar can crack under full pressure; test first |
Ask your prospective company: "Do you do soft washing for siding and roofs?" If they say they pressure wash everything at full pressure, that's a sign they're cutting corners.
3. Ask About Their Cleaning Chemicals
Most professional companies use a sodium hypochlorite (bleach) solution to kill mold and algae at the source — not just blast it off the surface. Without the chemical treatment, algae regrows within weeks.
The concern for Charleston homeowners: runoff. Low-dilution bleach solution kills plants, damages lawn grass, and can harm pets. A professional company should:
- Pre-wet surrounding plants before starting
- Use appropriately diluted solutions (3–6% for most surfaces)
- Rinse plants and surrounding areas after the job
Ask: "What do you do to protect landscaping?" The answer tells you a lot about their professionalism.
4. Get an In-Person or Photo Quote — Not a Phone Quote
A legitimate pressure washing quote depends on:
- Square footage of surfaces being cleaned
- Level of buildup (light mildew vs. black algae vs. years of neglect)
- Accessibility (two-story homes require different equipment)
- Surface types (concrete vs. painted wood vs. brick)
A company quoting "$150 for the whole house" over the phone without seeing it either doesn't know what they're getting into or plans to do a poor job. Accurate quotes require photos at minimum, in-person for large jobs.
5. Check Reviews Specifically for Charleston
Charleston's historic district has special considerations — aged brick, stucco, painted wood siding on historic homes. A contractor with great reviews in a Charlotte suburb may not have experience with the specific materials and preservation requirements of Charleston's older homes.
Look for Google reviews that specifically mention:
- Jobs in the Peninsula, Mount Pleasant, James Island, or other Charleston areas
- Similar surface types to yours (historic brick, vinyl siding, wooden decks)
- Before/after results and quality of finish
What You Should Expect to Pay
In Charleston, expect to pay:
- House exterior (soft wash): $200–$500 depending on size and condition
- Driveway + walkways: $100–$250
- Deck cleaning: $150–$400
- Roof soft wash: $300–$600
- Full property bundle: $500–$1,000+
Significantly cheaper quotes usually mean cutting corners on chemicals, insurance, or equipment. You'll be calling someone else in six months when the algae is back.
Find Verified Pressure Washing Pros in Charleston
ProPulse lists local pressure washing companies in Charleston who are insured, use proper soft-washing techniques, and have real verified reviews from local homeowners.