Before & after
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A completed Code 3 Cleaning job covering roof washing on a 2-story home in Zion, IL. Below is what we found on arrival, how it was cleaned and what the surface looked like afterwards.
What we found on arrival
The surface in question was roof shingles.
What the property was dealing with:
- Algae
- Mildew
- Mold staining
- Black streaks
- Moss
- Dirt / grime
- Organic buildup
- Weathering
Algae is the green film that takes hold wherever a surface stays damp long enough to support it. In this climate that means the north and east elevations first, and anything shaded by trees or a neighbouring building.
Mildew sits in the same damp conditions as algae but shows up as grey and black speckling rather than a green sheet, and it tends to concentrate under eaves and around window trim where airflow is poorest.
Mould staining goes beyond surface dirt — it has a root structure, which is why rinsing alone brings it back within weeks. It has to be killed rather than blasted off.
Black streaking on a roof is a bacteria that feeds on the limestone filler in asphalt shingles. It starts at the ridge and runs downward with the rainwater, which is why it always looks like it is dripping.
Moss is the one worth catching early. Unlike staining, it holds water directly against the surface and lifts shingle edges and paver joints as it thickens, so it does structural work rather than just looking bad.
General dirt and road film builds up from traffic, wind and rain splash. On its own it is cosmetic, but it holds moisture against the surface and gives organic growth something to anchor into.
Organic buildup is the broad layer of growth, pollen, spores and airborne debris that accumulates on any exterior surface left alone for a few seasons.
Weathering is the surface going grey and dull as UV and moisture break down the top layer. Cleaning takes it back to sound material, but it does not reverse age — it shows you what you actually have.
How it was cleaned
This job was done using a roof-safe low-pressure application that kills the growth at the root and lets rainfall carry it off, rather than stripping anything mechanically.
A roof never takes pressure. Asphalt shingles shed their protective granules under a wand and do not get them back, which trades a cosmetic problem for a structural one. Roof cleaning here is a low-pressure application that kills the growth and lets the weather rinse it.
Roof cleaning is the job where the wrong approach costs the most. Pressure takes granules off asphalt and shortens the life of the roof, so what looks like a faster clean is really pulling years off a covering that costs thousands to replace. Anyone who turns up with a wand for a roof is quoting a different job from the one that should be done.
The result
Black streaking and organic growth were substantially reduced.
Heavy oxidation on siding around entire home. Heavy moss and algae build up on roof as well.
Work completed by Matt Henby.
Why exterior surfaces here need this
Zion was laid out as a planned town, and that is the thing that actually shapes the work here. The original grid is largely intact, which means a concentration of genuinely old housing in one place rather than scattered among newer builds — painted wood, original trim, soffits that have been repainted more times than anyone has counted. Pressure is the wrong tool on all of it. The solution does the cleaning and the rinse stays low, and a crew that treats century-old trim like vinyl will leave marks on it that no second wash removes.
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