Roof Cleaning in the Quad Cities, IL & IA
Those black streaks are a living organism, not dirt. We treat the roof instead of blasting it, and the shingles stay where the manufacturer put them.
What the black streaks actually are
The dark stripes running down a south or west-facing roof are Gloeocapsa magma, an algae that feeds on the limestone filler in asphalt shingles. It arrived in the Midwest decades ago and it spreads by air, which is why one house on a block gets it and then the neighbors do.
It is not only cosmetic. The colony holds moisture against the shingle surface and reduces reflectivity, and where it is allowed to build into moss it lifts the shingle edge and lets water track underneath. Left long enough it shortens the usable life of the roof.
Moss is the further stage, and it is common on the shaded valleys and north slopes of older Quad Cities homes with tree cover. Moss has a root structure and holds standing water, and that is a decking problem, not an appearance problem.
Why we will not pressure wash a roof
Pressure washing strips the ceramic granules off asphalt shingles. Those granules are the shingle's UV protection and its fire rating, and once they are in the gutter they are not coming back. It also voids most shingle warranties outright — every major manufacturer specifies low-pressure chemical cleaning.
So we soft wash. A cleaning solution is applied at low pressure, kills the algae and moss where it sits, and the roof continues to clear over the following weeks as rain rinses the dead growth away. It is slower to look finished than a pressure wash, and it is the only method that does not cost you roof life.
How the job runs
- Roof inspected from the ground and the edge — pitch, shingle condition, valleys and any lifted or missing shingles noted before we start.
- Gutters checked; heavy debris removed first so runoff has somewhere to go.
- Landscaping and downspout discharge areas saturated and protected.
- Solution applied evenly at low pressure, working with the slope so nothing pools.
- Runoff monitored and beds rinsed throughout the application.
- Final rinse of siding, windows, walks and driveway.
What to expect afterward
Moss and lichen die on contact but stay attached until weather works them loose, so a mossy roof keeps improving for several weeks. Algae streaking lightens quickly and continues to fade. We tell homeowners to judge the result a month out, not the same afternoon — anything that looks perfect the instant it is finished was almost certainly cleaned with pressure.
What is included — and what is not
Included in a standard roof cleaning job:
- Full soft wash treatment of accessible roof planes
- Algae, moss and lichen treatment
- Landscaping saturation and protection
- Rinse-down of siding, glass, walks and driveway after treatment
- Photo documentation of roof condition we notice along the way
- Honest assessment of whether cleaning is the right call at all
Not included as standard, quoted separately when you need it:
- Any roof repair, flashing or shingle replacement
- Cleaning roofs with widespread curling, lifting or missing shingles
- Walking steep or brittle roofs — we work from the edge and from ladders
- Gutter cleaning, unless added to the quote
- Instant removal of moss mats, which weather off over the following weeks
Signs it is time to book
- Black streaks running vertically down the sunny slopes
- Green fuzz or clumps in the valleys and along the north side
- Granules collecting in the gutters or at the bottom of downspouts
- Shaded sections that stay damp days after a rain
- A neighbor's roof streaking the same way — it spreads
- You are selling and the roof is the first thing in the listing photo
Pricing
Quote-only, and firm. Price depends on the size of the home, access, and the condition of the surface, so instead of publishing a starting-at number that changes the moment we see the property, we look at the actual job and give you a fixed price before any work begins. No hourly meter, and the number we quote is the number you pay. Call (309) 507-6816 — most homes can be quoted in one conversation.
What customers say
Grant (my tech) explained what he would be doing before he started and walked me around any areas that could pose potential problems in the future. Very friendly and courteous.
They did a great job on our windows. Moved the outside furniture and replaced everything just where it was. I highly recommend them.
Been using Waterwerks for several years now. Always a great service. Efficient, friendly, and effective. It's amazing how much cleaner my windows are.
Verified reviews from our Google Business Profile — 4.8 stars across 126 reviews.
Roof Cleaning questions we get
- Will roof cleaning void my shingle warranty?
- Soft washing is the method shingle manufacturers specify, so no. Pressure washing is what voids warranties, because it removes the protective granules. We do not pressure wash roofs for that reason.
- How soon will the roof look clean?
- Algae streaking lightens within days. Moss and lichen die immediately but need a few weeks of weather to release and wash off. Judge the result about a month out.
- Do you walk on the roof?
- As little as possible. Most work is done from ladders and the roof edge with extended reach. Foot traffic damages shingles, particularly in heat, so we avoid it unless the pitch and condition genuinely allow it.
- Should I clean the gutters at the same time?
- Yes, and it is usually cheaper together. Runoff carries dead growth into the trough, so clearing the gutters after the treatment is the sensible order of operations.
Related services
Window Cleaning
Spot-free glass inside and out with pure deionized water.
Gutter Cleaning
Clear downspouts before the freeze-thaw season hits.
House Washing
Low-pressure soft washing that kills siding algae at the root.
Concrete Cleaning
Even, stripe-free driveways, sidewalks and patios.
Deck Cleaning
Gentle wood-safe cleaning that preps for stain or seal.
Fence Cleaning
Green film and grey weathering washed off vinyl or wood.
Want to know if we cover your town? See our Quad Cities service areas.