Deck Waterproofing & Flashing in Lynnwood, WA
Leaks under a deck or balcony? We find where the water gets in and seal it for good. 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 Lynnwood and nearby Edmonds and Mountlake Terrace.
Before
AfterFlashed and rebuilt
Why waterproofing comes up so often in Lynnwood
Kick-out flashing is missing on a surprising number of Lynnwood homes, especially split-levels where a lower roof meets a two-story wall. Without it, roof runoff pours behind the siding and rots the wall below, sometimes all the way to the sill. Deck ledgers installed with no metal flashing are another common source of hidden leaks. We install kick-outs, ledger flashing and Z-flashing at horizontal panel joints, build sill pans for doors that open onto decks, and apply waterproof membranes on decks over living space. Each detail is lapped so water drains away from the house instead of into it.
Lynnwood’s neighborhoods were mostly built during the 1960s, 70s and 80s as the area grew along Highway 99 and I-5. Ramblers, split-levels and two-story homes dominate, many still with original cedar, plywood or T1-11 siding and attached pressure-treated decks. Meadowdale has larger lots and some view homes looking toward the Sound, while the streets around Alderwood and North Lynnwood are more uniform tract development. Near City Center and the new light rail station, townhomes and apartments are replacing older houses. Many single-family homes have reached the point where original siding, decks and windows all need work at roughly the same time.
Lynnwood sits on a plateau in the middle of south Snohomish County, often right under the convergence zone, where showers linger longer than in nearby cities. It does not take direct waterfront exposure the way Edmonds or Mukilteo do, but long wet winters, moss and shade from remaining fir stands keep exteriors damp. Homes near Scriber Lake, Hall’s Lake and creeks such as Swamp Creek see more fog and dampness. Low-slung split-levels with siding close to grade suffer most from splashback and standing water around the foundation.
Our crew comes out from our Woodinville office, and we also work in nearby Edmonds, Mountlake Terrace, Mill Creek and Bothell.
When to call about waterproofing in Lynnwood
- A deck that slopes toward the house
- Rot or stains under windows and doors
- Streaks down the wall below a roof edge
- Stains or drips on the ceiling below a deck or balcony
- Water pooling against the house after rain
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 Lynnwood
What we do in Lynnwood
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.
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.
Neighborhoods and permits in Lynnwood
Meadowdale’s wooded, sloped lots stay shaded and damp, and homes with views toward the Sound take more wind. Alderwood and North Lynnwood split-levels have decks and siding sitting close to grade, where splashback and pooling cause rot. Around Scriber Lake and Cedar Valley, lower ground and creek corridors hold moisture. Near Martha Lake, at the city’s northeast edge, many homes with Lynnwood mailing addresses are actually unincorporated and fall under county rules.
Inside city limits, matching repairs to a few boards or a stretch of trim often go ahead without a permit, whereas framing repairs, deck construction and bigger re-siding jobs normally need approval. Some Lynnwood mailing addresses, including much of Martha Lake, are unincorporated and fall to Snohomish County Planning and Development Services instead. We confirm which authority applies, the City of Lynnwood or the county, before starting.
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 Lynnwood
| 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 Lynnwood 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 Lynnwood: cost and timing
Most common causes
Doors without sill pans
Water that gets under a threshold runs into the subfloor and the room below.
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 Lynnwood
Waterproofing in Lynnwood 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 Lynnwood 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…”
“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…”
“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.”
5.0 average from 106 reviews on Google, Thumbtack, Angi, HomeAdvisor and Yelp. Read our reviews on Google.
Questions Lynnwood homeowners ask about waterproofing
Is it worth repairing T1-11 siding on my Lynnwood home?
Can you coat over my existing deck in Lynnwood?
How long does a deck coating last?
Do you fix leaks around windows?
Can you waterproof a deck over a living space?
More from our crew in Lynnwood
Waterproofing near Lynnwood
Tell us about your waterproofing project in Lynnwood
- Licensed, bonded & insured
- Free on-site estimates
- 24-month workmanship warranty
Book a free waterproofing inspection in Lynnwood
We inspect the damage on-site, show you photos of what we find and give you a written price before any work starts.