Who cleans cedar shake roofs in Minnesota?
Modex handles cedar shake cleaning, moss and algae treatment, and re-stain cycles across the Twin Cities. Soft-wash only — never pressure-wash on cedar. Typical maintenance projects run $2,000 to $10,000 depending on roof size and condition. We'll tell you honestly whether cleaning extends the life of your roof or whether it's past saving and replacement is the smarter call.
Updated May 2026 · Reviewed by Joe Dvorak, Owner, Modern Exterior Systems
Honest assessment
Cleaning extends life — until it doesn't
A soft-wash and moss treatment can buy a sound cedar roof another 5–10 years. We'll walk yours, show you the photos, and tell you what we see. If the shakes are curling, splitting, or thinning past the point where treatment helps, we'll say so. Replacement with CeDUR or DaVinci synthetic outlasts a re-stain cycle by decades — at some point that's the smarter math. For the long-form context, Joe wrote up the disadvantages of cedar shake.
On-roof photos before any quote
Cleaning quoted when it actually buys you life — not just to book the job
Honest call when replacement beats another re-stain cycle
Scope
What we clean and treat on cedar shake
Three categories of cedar maintenance work
Soft-wash
Low-pressure cleaning that doesn't blow the shakes apart
Cedar is soft wood — pressure-washing splinters the grain, drives water under the shakes, and shortens the life of the roof. We soft-wash with a wood-safe surfactant, hand-rinse, and let the shakes dry out naturally. Removes dirt, light algae, and surface weathering without damaging the wood fiber.
Moss & algae
Treatment for north slopes and shaded sections
North-facing slopes and roofs under tree cover hold moisture, which feeds moss and algae growth. Untreated moss roots into the cedar and pulls fiber off the surface every freeze-thaw cycle. Sodium-hypochlorite treatment kills the growth without damaging the wood — $300 to $800 depending on coverage.
Re-stain
Oil-based stain after clean and dry
A clean, dry cedar roof takes a penetrating oil-based stain that restores color and slows weathering. Cycle runs every 5–7 years on a maintained roof. Skip the stain and the cedar greys out, cracks, and the cycle accelerates.
Process
Soft-wash, not pressure-wash
Cedar is soft wood. The wrong cleaning method destroys the roof faster than the weather ever would. Our four-step process keeps the shakes intact and the treatment effective.
On-roof inspection
We walk the roof, photograph every slope, and assess whether cleaning extends the life — or whether replacement is the smarter call.
Low-pressure soft-wash
Wood-safe surfactant applied at low pressure, then hand-rinsed. Lifts dirt and surface algae without splintering the cedar grain.
Moss and algae treatment
Targeted sodium-hypochlorite application on north slopes and shaded sections to kill moss and algae at the root before they thin the shakes.
Dry, then oil-based re-stain
Cedar has to dry completely before stain goes on. Penetrating oil-based stain restores color and slows weathering for the next 5–7 years.
Re-stain cycle
Cedar is a cycle — every 5 to 7 years
A maintained cedar shake roof runs on a 5-to-7-year cycle: soft-wash, moss treatment if needed, dry, oil-based stain. Stay on it and the roof lasts decades. Skip a cycle or two and the shakes grey out, crack, and the cost to bring it back climbs fast. We'll quote the cycle honestly — but if the math starts favoring cedar replacement or a synthetic alternative, we'll tell you that too. For background on the whole material category, see Joe's writeup on what you need to know about a wood roof.
Pricing
Cedar maintenance pricing ranges
Lump-sum quotes per scope. Final number depends on roof size, slope condition, and tree-cover exposure — but here's the range Twin Cities homeowners typically see.
Soft-wash cleaning
$0.75–$2.00 per square foot. Typical Twin Cities project $1,500–$5,000 depending on roof size and pitch.
Moss & algae treatment
$300–$800 add-on or standalone. Pricing scales with the north-slope coverage and how rooted the growth is.
Oil-based re-stain
$1.50–$4.00 per square foot. Most maintained Twin Cities cedar roofs land in the $3,000–$8,000 range on the re-stain pass.
Differentiators
Why choose Modex for cedar work
Three reasons cedar owners across the Twin Cities trust us with their roof.
Method
Soft-wash only — never pressure on cedar
Pressure-washing cedar splinters the grain and shortens the life of the roof. We soft-wash at low PSI with a wood-safe surfactant, hand-rinse, and let the shakes dry before any treatment goes on. Your cedar comes away clean, not damaged.
Honest call
We'll tell you when cleaning is throwing good money after bad
Some cedar roofs are past saving. If the shakes are splitting, thinning, or curling past the point where treatment helps, we'll say so — and walk you through replacement or synthetic alternatives instead of quoting a re-stain that won't hold.
Decades of cedar work
We install cedar, maintain cedar, and replace cedar — so the recommendation isn't skewed
We're not a one-trick cleaning crew. Modex installs cedar shake, sells synthetic alternatives, and runs maintenance cycles — which means we have no incentive to push you toward the wrong answer. The recommendation is whatever extends the life of your roof for the lowest long-term cost.
Questions
The questions cedar shake owners ask before they call.
How often should a cedar shake roof in Minnesota be cleaned?
Every 5 to 7 years for a maintained cedar roof. North-facing slopes and roofs under heavy tree cover may need a moss-and-algae treatment between full cleaning cycles. The Twin Cities freeze-thaw cycle is hard on cedar — skipping a cycle or two means the shakes grey out, split, and the next cleaning costs more (or stops being effective entirely). We'll walk yours, photograph it, and tell you honestly whether you're due.
Will pressure-washing damage my cedar shake roof?
Yes. Pressure-washing splinters the cedar grain, drives water under the shakes, and shortens the life of the roof faster than the weather ever would. Cedar is soft wood — it has to be soft-washed at low PSI with a wood-safe surfactant and hand-rinsed. Any contractor who pulls out a pressure washer on cedar is doing you damage they'll charge you to fix later. We use soft-wash only.
How much does it cost to clean and re-stain a cedar shake roof in Minneapolis?
Soft-wash runs $0.75–$2.00 per square foot. Moss and algae treatment runs $300–$800 as an add-on or standalone. Oil-based re-stain runs $1.50–$4.00 per square foot. Most Twin Cities cedar maintenance projects land between $2,000 and $10,000 depending on roof size, slope condition, and whether you're doing a full clean-and-stain cycle or just one component. We quote lump-sum per scope, not per line item.
When is replacement smarter than another cleaning cycle?
When the shakes are curling at the edges, splitting through the grain, or thinning to the point you can see daylight from inside the attic. At that point soft-wash and re-stain don't buy you life — the wood is past saving. We'll show you the photos and walk you through synthetic alternatives like CeDUR or DaVinci that outlast cedar by decades and don't need a re-stain cycle.
Do you handle moss treatment on north-facing slopes?
Yes. North slopes and shaded sections hold moisture, which feeds moss and algae growth. Untreated moss roots into the cedar and pulls fiber off the surface every freeze-thaw cycle. We treat with a sodium-hypochlorite application calibrated for cedar — kills the growth without damaging the wood. Treatment runs $300–$800 depending on coverage and how rooted the growth is. Call us at 952-206-6339 for a walk-through.
Need more help?
Call 952-206-6339 or schedule a free assessment.
Ready for an honest cedar assessment?
We'll walk your roof, photograph every slope, and quote the cleaning cycle that actually buys you life — or tell you straight if it's time to replace.
About
Modern Exterior Systems handles cedar across the Twin Cities
Modex is a women-owned roofing, siding, and window contractor based in Eden Prairie. We've worked cedar shake roofs across the western metro for decades — install, maintenance, and replacement. We hold five manufacturer certifications (CertainTeed ShingleMaster, Malarkey Emerald Pro, Atlas Pro+ Silver Select, LP SmartSide Certified, James Hardie Preferred), plus BBB A+ Accreditation, NRCA membership, and MN License BC762305. Cedar maintenance work demands honest assessment, the right method, and the willingness to say “replace it” when cleaning won't buy you life — that's what we deliver.
Reviewed by Joe Dvorak, Owner, Modern Exterior Systems · Updated May 2026
Further reading
Deeper writeups on the topics this page covers — written for homeowners by a Twin Cities installer.
March 21, 2026
What Are the Disadvantages of Cedar Siding? 7 Real Problems
Minnesota contractor reveals 7 real disadvantages of cedar siding after 20+ years replacing it. Cost, maintenance, rot, and better alternatives for MN homes.
May 31, 2026
Wood Roof: What You Actually Need to Know Before Installing One in Minnesota
MN contractor breaks down cedar shake vs shingles, real lifespan, fire treatment, maintenance, and the insurance problem. Honest synthetic alternatives. 952-206-6339.
May 31, 2026
Cedar Roofing Alternatives: 5 Modern Materials That Look Like Cedar But Outperform It
MN contractor on 5 cedar shake roof alternatives — CeDUR, DaVinci, Brava, stone-coated steel, CertainTeed Presidential Shake TL. Real pricing, lifespan, insurance fit. 952-206-6339.