Metal Roofs: The Flash Burning Risk

Metal roofing holds up beautifully against moss, algae, and grime — but it comes with its own hazard: flash burning. This happens when a cleaning solution is applied to a metal surface and allowed to dry in direct sun before it's rinsed off. As it dries unevenly under heat, it can etch or discolor the painted finish, leaving permanent blotchy streaks behind — essentially a chemical "sunburn" baked right into the coating.

Here's how we prevent it:

• Working in small, manageable sections so no area of solution sits and dries before it's rinsed
• Timing the job around heat and sun angle — early morning or overcast conditions are ideal; we avoid washing metal roofs during peak afternoon sun in the summer
• Keeping the surface wet throughout the process, rinsing promptly behind our own application
• Using metal-safe cleaning solutions formulated to break down algae and grime without being aggressive on painted or coated finishes
• Spot-testing an inconspicuous area first on any roof we haven't cleaned before

Done correctly, a metal roof cleaning restores its shine without any risk to the finish. Done carelessly — rushed, or washed in the wrong conditions — flash burning can leave marks that are there to stay.

Asphalt Shingles: Soft Wash Only, No Exceptions

Asphalt shingles are the opposite problem: they can't handle pressure at all. High-pressure water strips away the protective granules embedded in the shingle surface, and once they're gone, they don't come back. Beyond the physical damage, most shingle manufacturers explicitly void the warranty if a pressure washer is ever used on the roof.

The correct approach is a soft wash with an algaecide treatment:

1. We apply an approved algaecide/biocide solution across the roof surface
2. The solution is left to dwell, working down into the algae and moss at the root — not just the visible surface staining
3. A low-pressure rinse clears away the dead growth and residue, applied from a safe working position rather than pressure-blasting the shingles (if there is rain in the forecast, the algaecide is left to dwell until the rain rinses it away.) 😉

This kills the "algae" colony (often the black-streak-causing "gloeocapsa magma" bacteria common in our humid climate) rather than just knocking loose debris off the top, which is why soft-washed roofs tend to stay cleaner longer than a rushed pressure-washed job ever could — even though pressure washing isn't actually appropriate for shingles in the first place.

Pricing: Why Single-Story and Two-Story Aren't the Same Rate

Roof cleaning is typically priced per square foot of roof surface. But the story count of your home changes more than just the math — it changes the safety requirements for the whole job.

• Single-story roofs are more accessible, require less rigging, and generally move faster from setup to completion.
• Two-story roofs require additional fall-protection equipment, more time spent on ladder and harness setup, slower and more deliberate movement across the surface, and often an extra set of hands on site for safety as well as additional machinery such as a man-lift. That added time and equipment is reflected in a higher per-square-foot rate compared to a single-story home.

It's not that a two-story roof is "worse" to clean — it's that doing it safely simply takes more preparation, equipment and logistics, and we're not willing to cut corners on that part of the job.

While We're Up There: Worth Bundling In

Here's a practical tip: a lot of the setup, access, and safety equipment needed for a roof cleaning is the *same* setup needed for gutter cleaning and chimney cleaning. Once we're safely positioned on your roof, it's a much smaller lift (literally) to knock out those other jobs in the same visit — rather than paying for separate site visits and separate setup each time.

Pricing for those add-ons works a little differently than the roof itself:

• Gutter cleaning is priced per running foot of gutter, not per square foot
• Chimney cleaning is typically a flat, set price per chimney, regardless of roof size

If your gutters or chimney are due, bundling them into the same visit as a roof cleaning is almost always the more efficient — and more affordable — way to go as we often include a discount. 😁

FYI: The Future of Roof Cleaning

While we're on the subject of technology — somewhere out there, someone is almost certainly working on a fleet of heavy-duty roof-cleaning drones. Picture it: a swarm of pressure-washing drones descending on your roof at dawn, soft-washing your shingles and buffing your metal panels to a mirror shine before you've even had your coffee, all controlled from an app.

We're not there yet (and honestly, we like having a human double-checking for flash burn risk and loose flashing before it becomes a bigger problem). But if the drone fleet opportunity arises and becomes cost effective, you can bet we'll be the first ones in line to add it to the truck. Until then — you've got us, a harness, and a lot of careful attention to detail.

Ready to See the Difference?

Whether you've got metal, asphalt, or you're not sure which approach your roof needs, we'll walk the property, give you an honest recommendation, and a clear quote before any work begins.