Deck Building and Repair in Seattle
Custom deck building, waterproof composite decking, and deck repair for Seattle homes. Extend your outdoor living space with K Single Corp.
Seattle Waterproof Composite Deck Builder Since 2007
K Single Corp has built outdoor living spaces across greater Seattle for nearly two decades, with 15,000+ exterior projects completed and a 4.7-star reputation backed by 172+ Google reviews. Our composite decks routinely last 25 to 50 years in the Pacific Northwest, and our waterproof under-deck systems channel rainwater away so the patio below stays dry year-round, even through Seattle's wettest months.
We install Trex, TimberTech, and Fiberon composite decking, plus cedar and pressure-treated wood for homeowners who prefer natural materials. Every project includes structural framing built to current Washington code, footings sized for PNW soil and freeze conditions, and permits handled in-house. The result is a code-compliant, weather-tested deck designed for year-round outdoor living.
Licensed & Insured
WA #KSINGSC842B3, fully bonded, general liability + workers comp on every project.
10-Year Warranty
Workmanship warranty on every install, plus manufacturer material warranties up to 30 years.
4.7-Star Google
172+ Google reviews across King, Snohomish, and Pierce counties since 2007.
What's included with our decks service
- ✓ Composite Deck Construction
- ✓ Waterproof Under-Deck Systems
- ✓ Trex, TimberTech, Fiberon
- ✓ Pressure-Treated Framing
- ✓ Cedar Wood Decking
- ✓ Aluminum and Cable Railing
- ✓ Stairs and Landings
- ✓ Permits and Structural Engineering
Get a Free Decks Estimate
Most estimates scheduled within 48 hours. No obligation, no high-pressure sales, written line-item quote.
Request Free Estimate Call (206) 659-4349172+ verified Google reviews from Seattle, Bellevue, Kirkland, and Greater Seattle homeowners.
K Single Corp builds custom residential decks using composite, waterproof, and traditional wood materials, creating outdoor living spaces designed for year-round enjoyment in the Pacific Northwest. Browse our completed deck portfolio for color and railing examples, or bundle a deck with siding or exterior painting for combined exterior savings. Contact us for a free estimate.
Waterproof composite decking is the ideal choice for the Pacific Northwest because it handles Seattle’s wet conditions without the constant upkeep that wood demands. Products from Trex, TimberTech, and Fiberon resist moisture, rot, mold, and insect damage without needing annual staining, sealing, or sanding. A composite deck looks great on day one and still looks great a decade later with nothing more than occasional cleaning.
Why Decks
What Sets Us Apart
Waterproof Composite Systems
Trex, TimberTech, and Fiberon decking that resists moisture, rot, mold, and insects. No annual staining or sealing required.
Wood Deck Options
Pressure-treated lumber and cedar decking for homeowners who prefer natural materials and a traditional look.
Permits Handled
We manage all building permits, structural engineering requirements, and city inspections as part of our service.
Year-Round Outdoor Living
Waterproof under-deck systems create dry covered space below upper-level decks, even during Seattle's rainy months.
15,000+ Projects Completed
Proven track record across the greater Seattle area since 2007. Licensed, bonded, and insured in Washington State.
At a Glance
WA License
KSINGSC842B3
Credentials
Licensed, Bonded, Insured
Service Area
King, Snohomish, Pierce
Warranty
10-year workmanship
Our Decks Process
Consultation and Design
We visit your home, discuss your vision, measure the space, and review material options within your budget.
Permitting
We handle all building permits, structural engineering, and scheduling of required city inspections.
Site Preparation
We clear the area, set footings or posts per engineering specs, and establish a level foundation.
Framing and Decking
Structural framing built to code, followed by surface board installation with consistent spacing and clean lines.
Railing and Finishing
Railing installed to meet code height and spacing requirements. Final city inspection and project walkthrough.
Consultation and Design
We visit your home, discuss your vision, measure the space, and review material options within your budget.
Permitting
We handle all building permits, structural engineering, and scheduling of required city inspections.
Site Preparation
We clear the area, set footings or posts per engineering specs, and establish a level foundation.
Framing and Decking
Structural framing built to code, followed by surface board installation with consistent spacing and clean lines.
Railing and Finishing
Railing installed to meet code height and spacing requirements. Final city inspection and project walkthrough.
Built for Pacific Northwest Conditions
Decks in Seattle's Climate
37+ inches of annual rain, 150+ overcast days, salt-air drift off Puget Sound, freeze-thaw at higher elevations. Every decks project we deliver is spec'd for what Seattle actually throws at it.
Built for PNW Rain
Composite boards resist swelling, warping, and rot through Seattle's 150+ rainy days per year, with no annual sealing required.
Moisture and Rot Defense
Sealed framing, proper joist spacing, and waterproof membranes stop moisture intrusion before it can damage your deck structure.
Year-Round Outdoor Space
Waterproof under-deck systems create a dry, covered patio below so you keep using your outdoor space through fall and winter.
Freeze-Thaw Tested Fasteners
Stainless and coated structural fasteners hold tight through PNW freeze-thaw cycles that loosen standard screws and nails.
Recent Work
Decks Projects in Seattle
K Single was recommended by another roofing company and we are really glad that we went with them. Out of all the estima...
Isidro and his crew are fantastic. Isidro is prompt to investigate an issue when asked, thorough in his explanation on t...
I was very impressed with the job they did on my roof and covered patio, they cleaned up every day after working and the...
We recently contracted K Single Corp to repair and reconstruct our bedroom level deck. Isidro Amaya was prompt in provid...
K Single Corp demonstrates professionalism, competence and responsiveness in roof repair services. Isidro and his crew h...
Love the new front porch, stairs and pavers. From beginning to end K Single Corp did a great job. I will definitely use...
Common Questions
Frequently Asked Questions
How much does a new deck cost in Seattle?
What is the best decking material for Seattle's climate?
How long does composite decking last?
Do I need a permit to build a deck in Seattle?
How long does it take to build a deck?
Can you repair my existing deck?
What is a waterproof deck system?
Does a new deck increase home value?
Other Services We Offer
From roofing to siding, gutters, decks, and more. K Single Corp handles it all.
Residential Roofing
Complete residential roofing services for Seattle-area homeowners. From full replacements to storm damage repairs, K Single Corp delivers proven results backed by 25+ years of experience.
Commercial Roofing
Reliable commercial roofing for Seattle-area businesses. TPO, PVC, metal, and flat roof systems installed and maintained by K Single Corp's experienced crew.
Roof Installation
Professional new roof installation for Seattle homes and businesses. Every material type, expert crews, and a 10-year workmanship warranty from K Single Corp.
Roof Repair
Fast, reliable roof repair for Seattle homes and businesses. Fix leaks, storm damage, missing shingles, and flashing failures.
Ready to Get Started?
Request a free estimate and find out why 15,000+ homeowners trust K Single Corp.
Most estimates completed within 24 hours.