NW Structural & Shoring — Since 1974
Hillside & Slope Stabilization in Seattle
Moving soil, leaning trees, a slope that bulges after heavy rain. We stabilize steep-slope properties with walls, piles, and drainage.
FREE SAME-DAY SITE VISITS · CALL JEFF (206) 714-0096
When you need this
Sliding or slumping slope
Soil creeping downhill, tension cracks, or a slide that has already moved. We stabilize the slope and section off problem areas.
Failing retaining wall
Bulging, leaning, or cracked walls are replaced with engineered structures designed for the real loads behind them.
Drainage problems
Water is behind most slope failures; we correct the drainage that is driving the movement.
Building near a steep slope
Work in an ECA buffer needs geotechnical review and engineering. We help coordinate a team for architectural, engineering, and geotechnical needs.
Why Seattle homes need it
Old houses, wet ground
Much of Seattle is built on glacial till and sand sitting over layers of impermeable clay. Through the wet months, water soaks in, perches on the clay, and can turn a stable-looking slope into a slide-prone slope. This is why the city maps so many hillsides as Environmentally Critical Areas, or ECA. ECA rules add permitting steps, geotechnical review, and construction limits that catch many owners off guard. We have worked these slopes for decades and know both the ground and the process.
Our approach
There is no single fix for a moving hillside. The right answer depends on how and why the slope is failing. In most cases, we can correct drainage, drive pin piles, and build pin pile landscaping walls – our specialty. When a slope requires more, we help coordinate a team for architectural, engineering, and geotechnical needs. Several measures can be combined to stabilize one slope.
We stabilize slopes and section off problem areas so a local failure cannot pull the rest of the hill down with it. We keep you informed at every step, from the first site visit through final inspection.
How it works
1
Site visit & estimate
Free and no pressure. We walk the site, listen, and give you a straight assessment with a written estimate.
2
Engineering & permits
We help coordinate a team for architectural, engineering, and geotechnical needs.
3
Lift/shore/build
Our crews do the structural work. Homes stay habitable during most projects.
4
Final inspection & sign-off
Work is inspected for quality, documented, and signed off before we call the job done.
Related services
Straight Answers
How do you stabilize a hillside?
Depends on the failure: drainage correction, pin piles, pin pile erosion walls, tiebacks, or engineered retaining walls — chosen with a geotechnical engineer.
What causes landslides in Seattle?
Winter-saturated glacial soils over impermeable clay layers.
Do I need a geotechnical engineer?
For ECA steep-slope work, usually yes; we coordinate the whole team.
What permits does slope work require?
Steep-slope/ECA review applies in Seattle; we handle permitting.
Recent hillside stabilization projects
Queen Anne hillside rescue
An engineered pin pile erosion wall stopped years of slope movement on a steep Queen Anne lot.
Get a straight answer about your house
Free site visit, honest assessment, written estimate – often the same day you call. Ask for Jeff.