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ANOKA COUNTY, MN
Roof washing in Coon Rapids, MN
Those black streaks are alive. We remove them with the no-pressure method shingle makers publish.
The black streaks on Coon Rapids roofs are a living growth, not dirt or age, and it settles where roofs stay damp: north slopes and anything under a tree. Glass House kills it with a soft wash at under 300 psi, where a pressure washer runs 3,000 to 4,000, so the shingles are never blasted.
Left alone, the growth holds moisture against the shingles and loosens the granules that shield the asphalt from the sun, so the roof ages years ahead of schedule. Killing it stops that damage from spreading, and every roof wash is backed by the Roof Washing Warranty.
ROOF WASHING WARRANTY
If treated growth returns, we re-wash the affected areas free in year one, and at half cost in year two.
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Insured to $2M
Owner-operated
Based in Ham Lake
COON RAPIDS SPECIFICS
What roof washing means in Coon Rapids
The local conditions that shape how Glass House approaches roof washing in Coon Rapids, and the standards it holds to on every visit.
TREES
Oak savanna and a pruning ban
Coon Rapids prohibits pruning or trimming oaks from April 1 to June 30 to protect its native oak savanna from oak wilt. It also had nearly 7,000 boulevard ash trees at risk from emerald ash borer. Oak shade keeps roofs and siding damp, which algae and moss need, and oak leaves fill gutters each fall. Ash killed by the borer turns brittle and drops limbs onto roofs and into gutters.
WATER NEARBY
The Mississippi and Crooked Lake
Coon Rapids lies along the Mississippi River, 12 miles north of Minneapolis, and shares Crooked Lake with Andover. Air along the river and the lake holds more moisture, so roofs, siding and decks dry slowly after rain and dew. Algae, mildew and moss take hold on surfaces that stay damp, usually starting on the shaded north side. Damp air near water invites moss, which holds water and lifts shingle edges.
HOMES
A median home built in 1983
The median Coon Rapids home was built in 1983, and about a quarter of homes date from the 1980s. Four decades of sun break the surface of siding and painted trim down into a chalky film, called oxidation, that streaks when rain runs over it. High pressure removes that film unevenly and can damage the surface beneath, so older siding needs a gentle, low-pressure wash. Shingles that age are already losing granules, and pressure would strip the rest.
OUR WARRANTY
Roof Washing Warranty
If treated growth returns within the first year, we re-wash the affected areas free. If it returns within two years of service, we re-wash at half cost. A wash cannot put back granules that are already gone, so the goal is a clean, even roof rather than a factory-new one. It is also not a substitute for shingle, flashing or ventilation repair.
Sources: City of Coon Rapids, Oak Wilt Control; City of Coon Rapids, Emerald Ash Borer (2025); City of Coon Rapids, About; Minnesota DNR, Crooked Lake; Point2Homes, Coon Rapids demographics (U.S. Census ACS 2019-2023).
HOW WE WASH ROOFS
Chemistry does the work. Pressure never touches your shingles.
Roofs receive a stronger mix than siding, because shingles are porous, plus a surfactant, an additive that helps the mix cling. Time and the weather then finish the job.
CARSON'S FIELD RULE
If the algae turns brown, it is coming down. If it turns black, it is going to come back. That color change is what Carson watches for after the treatment goes on.
01
Walk-around first
Every online quote is verified in person. Carson looks over the roof, the growth and the landscaping below before any work starts, so the mix suits your roof and any concerns are raised with you before the wash.
02
Protect the landscaping
Plants, shrubs and lawn beneath the drip line are soaked with water before and after the treatment. Any drift that lands on wet leaves is diluted to the point of being harmless, which is how landscaping comes through a roof wash well.
03
Apply as a fine mist
The treatment goes on as a fine mist at under 300 psi and coats the growth completely, with enough surfactant to hold it on the shingles. Nobody scrubs, brushes or blasts your roof at any point.
04
Let the rain rinse it
On many roofs the treatment is left on and the next rain does the rinsing, the gentlest rinse possible for the granules. Each rain reactivates the treatment, so the growth keeps dying and releasing and the roof keeps brightening for weeks after we leave.
05
Photos and a receipt
Every job ends with a walkthrough of the finished roof and before and after photos attached to your receipt, so you can see the result and keep a record of the work.
FOR COON RAPIDS HOMES
What to know before your visit
INSURANCE
A clean roof on record
More Minnesota insurers now inspect older roofs before renewing, often with aerial images, and a streaked, mossy roof can look neglected. Before and after photos from a professional cleaning document its care.
TREES
Trim the shade
Trimming branches that shade the roof lets it dry faster, but mind the timing: Coon Rapids prohibits oak pruning from April 1 to June 30.
GUTTERS
Keep the eaves dry
Clear gutters keep the eaves from sitting wet. A gutter that cannot drain holds water and debris against the roof edge, which brings on rot and organic growth.
HOW OFTEN
Every few years
A soft wash every few years keeps most roofs streak-free. Plan on one sooner under heavy shade or near water, where growth comes back faster.
PRICE AND WARRANTY
What roof washing costs, and what backs it
YOUR ROOF WASH, AT A GLANCE
COON RAPIDS
Roof washing
$800–$1,600
No-pressure soft wash for algae, moss and lichen
Roof Washing Warranty
Included
Free re-wash of affected areas in year one, half cost within two years
Walk-around and photos
Included
Concerns raised before we start, and a photo record after
Weather reschedules
Always free
Moved to a new date when it is too wet or windy to work safely
Builders and commercial sites
In person
Quoted in person by Carson
Typical 2,000–4,000 sq ft home
$800–$1,600
Roof washing typically runs $800–$1,600 — $800 for a 2,000 sq ft home and $1,600 for a 4,000 sq ft home. Yours depends on the home, so Carson confirms the exact price after he looks at it.
THE OWNER
The person who quotes your home does the work
Glass House is owned and run by Carson Brenny, with no crews, subcontractors or handoffs. He grew up in Ham Lake, went to Blaine High School and has worked full-time in exterior cleaning for six years. The person who quotes your home is the person who arrives, does the work and walks it with you at the end.
Every job receives the gentlest method that will do the work, because too much force or too strong a mix can cause damage that no cleaning undoes. Every homeowner receives a clear explanation of what is on the house, why the method was chosen and what cleaning can and cannot fix, before any money is spent.
IN CARSON'S WORDS
“It's my neighbors' homes: their biggest investment, one of the places they spend the most time, and where the people they care about most live. It's something everyone should enjoy, and I believe that.”
Carson Brenny, owner
WHAT IS INCLUDED
What a roof wash includes and leaves out
A roof wash kills the growth on your shingles and backs the result with a warranty. Repairs always belong to a roofer.
INCLUDED
In every roof wash
• A no-pressure soft wash of the whole roof, under 300 psi
• Black algae streaks, moss, lichen, mold and mildew treated
• Plants wet down before and after
• Growth that keeps releasing, so the roof brightens for weeks
• Warranty: affected areas re-washed free in year one, half cost in year two
NOT INCLUDED
Outside a roof wash
• Pressure washing, brushing or scrubbing shingles, ever
• Shingle, flashing, ventilation or drainage repair
• A factory-new look, since lost granules do not return
• Gutter cleaning, unless added to the visit
• Work on a roof too steep or wet that day
EQUIPMENT AND METHODS
The method the shingle makers publish
The soft wash system delivers the treatment as a fine mist at under 300 psi, with a reach of about 85 feet. The roof mix is around 6% sodium hypochlorite with a little surfactant, so it clings to the shingles. On many roofs the rain does the rinsing and keeps the treatment working for weeks, which leaves an even finish.
COON RAPIDS QUESTIONS
Roof Washing in Coon Rapids: FAQ
Do homes near the water in Coon Rapids cost more?
No. Being near the Mississippi or Crooked Lake does not change the price, and those homes are quoted the same way as any other in Coon Rapids. We do recommend a roof soft wash more often there, because humid air keeps surfaces damp after rain and morning dew, and damp surfaces are where algae and mildew grow back fastest.
Do you serve all of Coon Rapids?
Yes, every neighborhood in Coon Rapids. Glass House is based in Ham Lake, and Coon Rapids is part of its regular north metro service area, so there is no trip fee. Carson quotes, cleans and walks every job himself, wherever in Coon Rapids your home is.
What are the black streaks on my roof?
They are Gloeocapsa magma, a blue-green algae (a cyanobacteria) that arrives as an airborne spore and feeds on the limestone filler in asphalt shingles. The black color is a protective shell the colony grows against the sun. It is not dirt or age, and it settles where a roof stays damp longest, such as north slopes and shaded areas.
Will roof washing affect my shingle warranty?
Not the way Glass House does it. GAF, Owens Corning and CertainTeed publish their own methods for cleaning roof algae: a diluted bleach solution, a short dwell and a low-pressure rinse. That is soft washing, which we do at under 300 psi. Pressure washing strips the protective granules, and no manufacturer's published method calls for it.
Why is there a clean stripe under my chimney?
That clean strip below chimney flashing or a metal vent comes from copper and zinc washing down in the rain, and the algae cannot live in it. Algae-resistant shingles use the same idea, with copper granules that release a little each time it rains. If you are replacing your roof, ask for them.
Does it kill moss and lichen?
Yes, along with algae, mold and mildew. Thick moss can take a little longer to let go after it dies, and lichen roots into the shingle, so old lichen can leave bare spots where it grew. We point those areas out at the walk-around, before any work starts.
