Deck Waterproofing & Flashing in Kenmore, WA
Walkable waterproof coatings, slope fixes and flashing that keep water out of your walls and ceilings. When coatings wear through or flashing is missing at doors and walls, the leak often shows up far from where water gets in. We trace it to the source, replace any wet framing, correct slope and flashing, and finish with a walkable surface that drains away from the house. We serve homeowners across Kenmore and nearby Bothell and Lake Forest Park.
Before
AfterFlashed and rebuilt
Why waterproofing comes up so often in Kenmore
Many Kenmore homes were built before ledger flashing, kick-out flashing and window pans were standard practice, and the missing details cause much of the rot we repair. Decks over living space and balconies on newer townhomes rely on membranes and door thresholds that eventually fail. We open the problem area, repair any rotted framing, and install new membranes, ledger flashing, kick-outs and pans so water drains out and away from the house, even on walls that face the lake.
Kenmore wraps around the north tip of Lake Washington where the Sammamish River flows in. Most of its homes were built from the 1960s through the 1980s: split-levels, ramblers and two-story houses on wooded slopes in Inglewood, Arrowhead, Moorlands and Uplake, with lakefront and view homes along the Juanita Drive side. Cedar lap, hardboard and T1-11 siding are common, and many homes have large decks facing the lake or the woods. Newer townhomes and apartments have gone up near downtown Kenmore and along Bothell Way, mixing modern construction into an older housing stock.
Kenmore gets weather from two directions. Homes near the lake catch wind-driven rain and fog rolling off Lake Washington, which hits lakeside walls and decks hard. Up the hills, tall evergreens keep siding and decks shaded, and moss grows quickly on north-facing surfaces. The Sammamish River valley at the city’s low end holds morning fog and damp air. Steady winter rain on wooded slopes means many Kenmore homes stay wet on at least one side from fall through spring.
Our crew comes out from our Woodinville office, and we also work in nearby Bothell, Lake Forest Park, Kirkland and Woodinville.
When to call about waterproofing in Kenmore
- Stains or drips on the ceiling below a deck or balcony
- Streaks down the wall below a roof edge
- Cracked, peeling or soft deck coating
- A deck that slopes toward the house
- Rot or stains under windows and doors
Our waterproofing process, step by step
Trace the leak
Moisture readings, inspection openings and photos to find the real source.
Repair the substrate
Rotted plywood, joists or sheathing are replaced before sealing.
Correct slope and details
Proper slope, sill pans and flashing at every edge and door.
Apply the system
Primer, membrane and walkable top coat applied in layers.
Water test
We test the problem areas and show you the finished details.
Recent waterproofing projects near Kenmore
What we do in Kenmore
Slope correction
Fix flat or back-sloped decks so water drains away from the wall.
Window head flashing
Flashing and tape around windows to stop leaks into the wall.
Door and sill pans
Pan flashing under doors, where many balcony leaks start.
Kick-out flashing
Diverts roof water away from the wall at roof-to-wall joints.
Leak investigation
We trace leaks to the source before anything is sealed.
Walkable deck coatings
Waterproof coating systems for decks and balconies over living space.
Neighborhoods and permits in Kenmore
Homes along Juanita Drive and the lakefront take wind and spray off Lake Washington, so view decks and lakeside walls wear quickly. Inglewood and Arrowhead are hilly and heavily treed, with shade and moss on north walls and decks. Moorlands and Uplake are steep in places, sending runoff toward the uphill side of houses. Neighborhoods near Saint Edward State Park have mature forest close to the homes, while downtown has newer, denser construction.
Small like-for-like repairs usually don’t require a permit, while structural work, new decks and larger replacements usually do. The City of Kenmore handles residential permits, and lakefront or steep-slope lots can involve extra review. We check with the City of Kenmore before starting and keep you informed about what the job needs.
Deck and balcony surface options
| System | Best for | Expected life | Maintenance |
|---|---|---|---|
| Recoat existing membrane | Sound surface with a worn top coat | A few years per top coat | Keep drains clear, recoat when worn |
| New walkable membrane | Decks and balconies over living space | 10–15+ years | Top coat every few years |
| Membrane under decking | Dry space under a deck with a wood or composite surface | 15+ years | Keep gaps and drains clear |
| Rebuild, slope and membrane | Wet or rotted plywood, flat or back-sloped deck | 15+ years | Top coat every few years |
What waterproofing typically costs in Kenmore
| Project | Typical scope | Price range | Timeline |
|---|---|---|---|
| Flashing repair | Kick-out, head flashing or a door pan at one spot | $600 – $2,500 | 1 day |
| Recoat a balcony | Prep and top coat over a sound membrane | $1,500 – $4,500 | 2–3 days |
| New walkable membrane | Full membrane system on a deck or balcony | $5,000 – $14,000 | 4–7 days |
| Rebuild and waterproof | New plywood, slope correction, flashing and membrane | $12,000 – $30,000+ | 1–3 weeks |
These are typical 2026 ranges we see for waterproofing in Kenmore and nearby cities. Your price depends on what we find once the area is open, access and height, and the materials you choose. Every estimate is free, in writing and based on an on-site inspection with photos.
Waterproofing in Kenmore: cost and timing
Most common causes
Worn deck coatings
Coatings wear through first at doors, edges and posts, and water reaches the plywood underneath.
Decks that slope toward the house
Flat or back-sloped surfaces push water against the wall and door thresholds.
Missing kick-out flashing
Roof water runs down the wall instead of into the gutter and soaks the siding and framing.
What drives the price in Kenmore
Waterproofing in Kenmore depends on the size of the deck or balcony, how much substrate has to be replaced, slope correction and how many doors and walls need new flashing. Recoating a sound surface costs far less than rebuilding a wet one. You get a written price after we trace the leak.
Typical timeline
A recoat over a sound deck usually takes a few days including cure time. Rebuilding plywood, slope and flashing takes about one to two weeks, depending on weather.
Backed by a 24-month workmanship warranty
Written scope
You know exactly what is included before work starts, with photos of what we found.
Our own crew
The people who quote your job are the people who do it, start to finish.
Clean site daily
Debris is hauled away and your yard is left the way we found it.
24 months covered
If our workmanship fails within two years, we come back and make it right.
What homeowners near Kenmore say
“One of my windows leaked after I had them cleaned and so I called Eco Home Repair to take a look. I really appreciated the thorough inspection - they determined the leak was unique to the aggressive window washing and wouldn't happen in regular rain (it had…”
“Very professional, quick to respond, and able to schedule the work on short notice they treated our home and deck with care and did an excellent job. I would definitely hire them again for a future project.”
“I hired Eco Home Repair to do a leak repair under my balcony, deck waterproofing and slope correction, and underlying rot repair. They were professional, quick, and fairly priced; kept me in the loop throughout the whole process and was honest about what…”
5.0 average from 106 reviews on Google, Thumbtack, Angi, HomeAdvisor and Yelp. Read our reviews on Google.
Questions Kenmore homeowners ask about waterproofing
Is hardboard or T1-11 siding on my Kenmore home worth repairing?
Can you coat over my existing deck in Kenmore?
Do you fix leaks around windows?
What is kick-out flashing?
Can you waterproof a deck over a living space?
More from our crew in Kenmore
Waterproofing near Kenmore
Tell us about your waterproofing project in Kenmore
- Licensed, bonded & insured
- Free on-site estimates
- 24-month workmanship warranty
Book a free waterproofing inspection in Kenmore
We inspect the damage on-site, show you photos of what we find and give you a written price before any work starts.