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DECK WASHING
Deck washing for Ham Lake and the north metro
Algae, mildew and grime lifted from wood and composite with a gentle soft wash, never high pressure, by the owner who quotes it.
Deck washing removes algae, mildew, pollen and dirt from wood and composite boards, railings and stairs. Glass House uses a soft wash: a mild cleaning solution matched to your boards, left long enough to kill the growth, then rinsed away at low pressure rather than blasted off.
North metro decks sit under oaks, beside lawns and lakes, and in the shade of the house, where boards stay damp long enough for algae and mildew to take hold. Force is the wrong answer on a deck, because high pressure raises the grain and scars the surface it is meant to clean.
GENTLE BY DESIGN
High pressure never touches your boards. The soft wash is matched to wood or composite before it is applied.
★ Rated 4.9 on Google · 44 reviews
Insured to $2M
Owner-operated
Based in Ham Lake
WHY DECKS GREEN UP
Shade, oaks and damp boards
Algae and mildew need three things: shade, moisture and a surface to grow on. A north metro deck usually offers all three.
Oak country
Much of Anoka County sits on the Anoka Sand Plain, where bur oak and northern pin oak are the native trees, and Blaine calls oaks its most plentiful neighborhood shade tree. That shade keeps deck boards from drying out, and shaded, damp wood is where algae and mildew take hold first, much as they do on the north side of a house.
Wet leaves leave marks
Oak leaves left on a deck through a wet fall release tannins, natural plant compounds that leave brown marks on the boards, and leaves that stay put through the winter leave the most. Blowing the leaves off before they mat down is the easiest prevention there is, and it takes only a few minutes after a windy day.
Composite is not immune
Composite boards do not rot, but they are not free of maintenance. Mildew and algae grow on the dirt and pollen that settle on top of them, especially in the shade of the house. Because that growth sits on the surface rather than in the board, composite receives a lighter mix and a shorter dwell than wood.
Lakes and wetlands add moisture
Decks near Coon Lake, the Rice Creek Chain of Lakes or the wetlands that run through the north metro sit in damper air and green up sooner. Lake lots see more buildup and organic growth than most properties, because water, shade and humidity are exactly what algae and mildew need. Being on a lake does not change the price.
Sources: Minnesota DNR, Anoka Sand Plain ecological subsection; City of Blaine, Oak Wilt; Minnesota DNR, Coon Lake; Anoka County Parks, Rice Creek Chain of Lakes.
HOW WE WASH DECKS
The mix is matched to the boards
Wood and composite take different mixes and different dwell times (the minutes a solution stays on before it is rinsed). We always start with the lightest mix the surface will take and work up only if needed.
WHY NEVER HIGH PRESSURE
High pressure raises and splinters the grain of wood, leaving the boards fuzzy, and it can permanently scar composite and strip a finish. On a deck, force causes the very damage the cleaning is meant to prevent, which is why chemistry does the cleaning and the rinse stays gentle.
01
Walk it first
Every visit starts with a walk-around of the boards, railings, stairs and finish. Carson confirms the right mix for the surface and points out anything loose, rotted or failing before cleaning begins. Fragile surfaces, such as rotten wood or a failing coating, may call for a signed damage waiver.
02
Protect the plants
Planters, beds and landscaping around and beneath the deck are soaked with water before, during and after the wash, along with nearby windows. Any drift that lands on a pre-wet surface is diluted to the point of being harmless, which is why plants survive a soft wash.
03
Apply the right mix
A sodium hypochlorite solution, similar to a diluted household bleach, goes on at 1 to 3 percent, lighter on finished wood, and dwells 10 to 15 minutes to kill the growth at the root. Composite receives a lighter mix and a shorter dwell. A second application is normal; an overly strong mix damages finishes permanently.
04
Rinse delicately
The rinse runs at low pressure from top to bottom, railings and stairs included, so no solution is left behind to discolor the boards. High flow at low pressure rinses the deck thoroughly and efficiently, using less water overall than working at one surface for an hour.
05
Walk it, then let it dry
Carson walks the finished deck with you, and before and after photos are attached to your receipt. Keep people, pets and furniture off the boards for at least 3 hours while they dry.
BEFORE AND AFTER
One railing, one soft wash
BEFORE
Yellow-green lichen and algae growing along a composite deck railing, before deck washing.
AFTER
A composite deck railing with black balusters, clean and wet after deck washing.
KNOW YOUR DECK
Wood, composite and cedar clean differently
Each material responds differently to a soft wash, and cedar is a separate project.
DECK TYPE
WHAT IT NEEDS
WHAT WE DO
Pressure-treated wood
A gentle soft wash and a delicate rinse. High pressure raises the grain.
Deck washing
Composite boards
A lighter mix and a shorter dwell. The growth sits on the surface, not in the board.
Deck washing
Cedar
Washing grays cedar, so it is washed, brightened to restore the color, then sealed.
Cedar restoration, the one wood we seal
Peeling stain or paint
The coating is failing, and washing can make that easier to see.
Pointed out before we begin
Soft, rotted or loose boards
A repair, not a cleaning.
A deck contractor. We photograph it for you.
HOW PRICING WORKS
Quoted by the size of your deck
YOUR DECK WASH AT A GLANCE
QUOTE FIRST
Deck washing
From $500
Wood or composite deck, stairs and railings
Service Plan member on a Preferred day
From $350
25% member rate, plus 5% on a Preferred day
Cedar restoration
In person
Wash, brighten and seal, the one wood we seal
Plant protection
Included
Landscaping rinsed before, during and after
Walk-around first
Included
Loose boards and failing finishes flagged before we start
Priced by the size and material of your deck
From $500
Starting at $500. Deck washing is quoted by the size and material of the deck, after Carson sees it and its finish. Cedar restoration (wash, brighten, seal) is priced by Carson in person, only. Send a photo or book a walk-around, and you will receive an exact price before any work starts.
WAYS TO SAVE
Service Plan members
25% off any other work, holiday lighting included
Veterans
10% off any service
Same-day neighbors
15% off for both households
Preferred day
Another 5% off on top of any other saving, up to 25% in all
Seniors 65 and older
$50 off
Three projects together
10% off
Discounts don't combine — you receive whichever single saving is largest. Then a Preferred day can take another 5% off, up to 25% in all (Service Plan members aren't capped).
This season’s flash sale is shown at the foot of every page.
GUARANTEES
What backs the work, word for word
These are printed word for word on your quote, your work order and your invoice.
INCLUDED
Workmanship Standard
If we miss an area or leave normal cleanable residue, tell us and we'll re-clean or touch it up. Our guarantees cover the cleaning result — not repairs, replacements, permanent stains, or conditions that can't be safely corrected through cleaning.
WHAT IS INCLUDED
What deck washing includes, and what it does not
Glass House washes wood but does not stain or seal it, with one exception. Only the work on your approved estimate is included, and anything added on site is priced separately.
INCLUDED
In every deck wash
• Deck boards, railings and stairs
• Algae, mildew, pollen and dirt lifted
• A mix matched to wood or composite, lighter on finished wood
• Plants wet down before, during and after
• A delicate, low-pressure rinse
• Before and after photos attached to your receipt
NOT INCLUDED
Outside a deck wash
• Staining or sealing wood, except cedar restoration
• Fixing a peeling, failing or unsealed finish
• Rot, loose boards, splinters or structural repair
• Rust, oil, paint and other specialty stains
EQUIPMENT AND METHODS
A soft wash made for wood
The soft wash system applies sodium hypochlorite at 1 to 3%, lighter on finished wood and with no surfactant (the additive that makes a mix cling, and takes far more water to rinse). It dwells 10 to 15 minutes and is rinsed delicately. Composite receives a lighter mix and a shorter dwell, and no pressure wand ever touches the boards.
SAFETY AND CARE
Gentle on the boards, safe for your family
Wood and composite scar easily under force, and a deck is where a family walks barefoot, so this wash is built around both.
THE EQUIPMENT
50 to 300 psi, like a hose
The soft wash system runs at 50 to 300 psi (pounds per square inch), where a pressure washer runs 3,000 to 4,000, so the solution comes out much like a garden hose. It delivers 11 gallons per minute, which lets the deck be treated and rinsed efficiently with less water overall.
CEDAR
The one wood treated differently
Cedar is delicate. A mix that is too strong permanently breaks down lignin, the natural binder in the wood, raises fuzzy fibers, strips the protective natural oils and leaves an uneven finish. Sodium hypochlorite also turns cedar gray at any strength, which is chemistry rather than a mistake, so cedar receives its own restoration: wash, brighten, then seal.
YOUR FAMILY
Pets and children are welcome
Pets and children are welcome at home while we work, and there is no need to keep anyone indoors. We ask only that nobody runs into the work area while solution is on the boards, and that the deck stays clear until it has dried. Mentioning pets when you book helps plan the visit.
BEFORE WE ARRIVE
Wasp nests stop the work
An active wasp or hornet nest stops work in that area, because no one can work safely around wasps. Our policies ask homeowners to have any nest treated before the visit. If an active nest turns up on the day, Carson finishes everything else, tells you what was left and why, and arranges a return visit.
THE OWNER
A deck is where summer happens
Glass House is owned and run by Carson Brenny. He grew up in Ham Lake, went to Blaine High School and has worked full-time in exterior cleaning since 2020. The person who quotes your deck is the person who mixes the solution, rinses every board and walks the finished deck with you.
A deck is where much of a Minnesota summer happens: coffee in the morning, dinner with friends, children and dogs running in and out. That is why Carson washes decks with the lightest mix that works, rinses them gently, and says plainly what a wash can do and when a board needs more than cleaning.
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
✓
A mix matched to wood or composite
✓
Rinsed gently, never blasted
✓
Before and after photos with every job
HONEST EXPECTATIONS
What a deck wash does, and does not do
It lifts growth and grime
Algae, mildew, pollen and dirt come off, and the boards look clean and even again. Wood and composite are porous, so heavily stained boards may need a stronger treatment and may not return to a perfectly uniform finish. Carson tells you at the walk-around which areas are likely to show.
We do not stain or seal
Deck washing, yes. Staining and sealing, no, with one exception: cedar restoration, the only wood we seal. A properly sealed finish is what decides how a deck ages, because it helps prevent rot, protects the wood from Minnesota weather and makes the stain last longer.
A failing finish shows
If a stain or sealer is already peeling, washing will not fix it and can make it easier to see. Wood that is not properly sealed can also discolor under a wash, and Glass House cannot be responsible for improperly sealed surfaces, so Carson points these areas out before any work begins.
It is not a repair
Rot, loose boards, splintering and structural problems need a deck contractor, and Glass House is a cleaning service, not a repair service. Anything noticed during the visit is photographed, noted and shown to you, so you know exactly what to raise with a contractor.
MINNESOTA TIMING
When to wash your deck
SPRING
Ready for summer
Winter grime and last fall's leaf marks come off before the patio furniture goes back out, so the deck is ready for the first warm weekend.
SUMMER
Anytime it greens up
Shaded decks can green up mid-season, and a wash brings them back. In the heat, surfaces are pre-wet and worked in sections so the solution does not dry on the boards.
FALL
Clear the leaves
Blow oak leaves off before they mat down and leave tannin marks through the winter. Exterior washing is booked through November 15.
WINTER
No washing
Water turns to ice on cold surfaces, so exterior washing pauses for winter. Our exterior season runs March 1 through November 15.
Between washes, keep planters on feet so water can drain, trim shrubs back so air moves across the boards, and aim sprinklers away from the deck.
WHERE WE WORK
Deck washing across the north metro
Glass House is based in Ham Lake and washes decks throughout Anoka County and the Twin Cities north metro.
Each city page covers the local conditions that affect your deck. The surrounding north metro is served as well, and we travel farther for a small trip fee.
DECK QUESTIONS
Deck washing FAQ
Will you pressure wash my deck?
No. High pressure raises and splinters the grain on wood and can permanently scar composite. Glass House soft washes decks instead: a mild solution matched to the boards is left to kill the growth, then rinsed away at low pressure, 50 to 300 psi, which comes out much like a garden hose.
Do you stain or seal decks?
No, with one exception. Glass House washes wood decks but does not stain or seal wood, other than cedar. Cedar turns gray under any wash solution, so it receives a separate restoration: it is washed, brightened to restore its color, then sealed. Cedar is the only wood we seal.
Can you clean a composite deck?
Yes. Composite boards do not rot, but algae and mildew grow on the dirt and pollen that sit on top of them. Because the growth sits on the surface rather than in the board, composite receives a lighter mix and a shorter dwell than wood, followed by a low-pressure rinse.
Why is my deck turning green or black?
Shade and moisture. Algae and mildew need shade, moisture and a surface to grow on, so decks under oaks, on the north side of the house or near a lake or wetland stay damp and grow them first. Aiming sprinklers away from the deck and trimming shrubs back so air can move helps slow the return.
Is deck washing safe for my plants and pets?
Yes. Plants, beds and nearby windows are soaked with water before, during and after the wash, so any drift is diluted to the point of being harmless. Pets are welcome at home while we work. Please keep them off the deck for at least 3 hours afterward while the boards dry.
How soon can we use the deck again?
Allow at least 3 hours after the final rinse before people, pets or furniture go back on the deck, so the boards can dry. Carson confirms the timing when he walks the finished deck with you, and before and after photos are attached to your receipt.
Will washing take my deck stain off?
A sound, properly sealed finish stays in place. A stain or sealer that is already failing can look more obvious once the dirt is gone, and wood that is not properly sealed can discolor under a wash. Carson points out any failing or unsealed areas before the work begins, so nothing comes as a surprise.
What does deck washing cost?
Deck washing is quoted by the size and material of your deck. Send a photo or book a walk-around, and Carson will confirm the exact price before any work starts. Every online quote is verified in person, so the mix and the price both match the deck you have.
