So last month I noticed my metal roof looking nasty – like someone smeared green yogurt all over it. Moss everywhere, streaks down the sides, just ugly. Figured it was time for a professional clean, but honestly? Had no clue where to start. Googled a ton of local "metal roof cleaning pros" and man, it felt like falling down a rabbit hole of vague promises and shiny websites.

The First Company - Big Promises, Zero Substance

Called up this place boasting about being "experts." Guy shows up, barely glances at the roof from his truck window. Seriously, didn't even get out. Gave me a rock-bottom quote over the phone saying "Easy job, one day!" Felt sketchy. Asked him what kind of cleaning solution they'd use for the moss and stains. He mumbled something like "Special mix, professional-grade." Wouldn't tell me anything solid. Big red flag number one: They never actually inspected the roof properly. No thank you.

Round Two - Slightly Better, Still Fishy

Second company sent a guy who actually climbed up there. Took some pictures, pointed out the thick moss patches. Okay, better start. The quote was reasonable. Then I asked the magic question: "What chemicals are you spraying onto my roof?" He paused. "It's sodium hypochlorite," he says, trying to sound smart. I'm like, "Is that bleach? Can it damage the metal?" He gets flustered and says "All chemicals are safe!" No explanation of dilution, rinse process, or protective coatings. Red flag number two: Couldn't explain their chemicals clearly or how they avoid wrecking the roof finish. Dodged that bullet.

Finally, The Good Guys

Feeling discouraged, I almost gave up. Found another listing with good reviews. Their rep arrived early, spent a full 20 minutes on the roof with a moisture meter, even checking for weak spots near the fasteners I never knew existed. Detailed report showing where moss was thickest and potential rust spots starting. He then laid it out plain:

• Low-Pressure Only: Absolutely no pressure washers, just soft wash.
• Cleaning Mix: Using a specific biodegradable surfactant mix plus a gentle bleach solution, heavily diluted and buffered to prevent corrosion. Showed me the SDS sheet!
• After Treatment: Explained they'd apply a zinc sulfate spray after cleaning to slow down future moss growth.

But the kicker? When I asked about warranty or follow-up. He said, "We do a walk-around with you immediately after, and I'll leave you my cell. Any issue, even a tiny spot we missed? Call me within 48 hours, we fix it. Plus, here’s a simple guide on spotting early moss." Sign number three nailed: Crystal clear after-service plan. Hired them on the spot.

They showed up with legit gear: soft wash system, guys wearing harnesses, proper ground cloths. Took a full day, not some rushed mess. Roof looked brand new. Moral of the story? Always, always check those three things: Thorough Inspection Beforehand, Clear Chemicals Explained, Solid After-Care Plan. Skip any company that waffles on even one. Total game changer, roof still looks pristine months later.