NW Structural & Shoring — Since 1974
Frequently asked questions
Straight answers on house lifting, foundations, pin piles, slopes, and shoring from Seattle’s structural specialists. Each section links to the full service page.
House Lifting
How much does it cost to lift a house in Seattle?
Most straightforward lifts start in the low tens of thousands; a lift with full foundation replacement typically runs $40,000–$100,000+ depending on size, access, and soil. Every project gets a written estimate after a free site visit.
Can we live in the house while it is lifted?
In most of our projects, yes — homes generally stay habitable while cribbed, though utilities are briefly disconnected during the lift itself.
How long does a house stay lifted?
Typically 3–6 months while the new foundation, basement, or first floor is built beneath it.
Do I need a permit to lift my house in Seattle?
Yes. Lifts require structural permits (SDCI in Seattle, county elsewhere). We handle engineering and permitting as part of the job.
Foundations
Should I repair or replace my foundation?
If walls crumble, settle unevenly, or you want more height/space below, replacement usually beats patching; we advise honestly at the site visit.
What are the signs of foundation failure?
Stair-step cracks, sloping floors, sticking doors, gaps at trim.
Why do Seattle foundations fail?
Rain-saturated glacial soils shift and settle; many older foundations are unreinforced concrete or post-and-pier.
Can a post-and-pier foundation be replaced?
Yes — we lift the house and build a full perimeter foundation beneath it.
Pin Piles
What are pin piles?
Small-diameter steel pipe piles driven to load-bearing soil to support or re-level a structure.
How deep do pin piles go?
To refusal — commonly 15–40 ft, up to ~75 ft in soft soils.
How do pin piles compare to helical piers?
Both underpin; pin piles excel in tight access and Seattle’s till, and are recognized by SDCI’s Director’s Rule 10-2009.
Will pin pile installation damage my house?
No — installation is low-vibration and works in crawl spaces and close quarters.
Hillside Stabilization
How do you stabilize a hillside?
Depends on the failure: drainage correction, driven piles, soldier-pile 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.
Excavation
Can you add a basement under an existing house?
Yes — lift or shore the house, excavate, pour a new foundation; classic crawl-to-basement conversion.
How much headroom can a dig-out add?
Typically 12–36 inches, or full-height with a lift.
Can you work on tight-access sites?
We work city lots, waterfront, and hillside sites with compact equipment.
Do you handle grading and site prep?
Yes, including drainage-aware finish grading.
Additions
Can my foundation support a second story?
Many older ones can’t without reinforcement — we assess and upgrade footings before framing.
Should we build up or out?
Up preserves yard and usually avoids setback issues; we handle the structural side either way.
Do we need to move out during construction?
Often not for foundation/lift phases; your GC’s finish schedule governs the rest.
Do you work with architects?
Yes — we’re the structural subcontractor GCs and architects call.
Structural Framing
What counts as structural framing?
Load-bearing walls, beams, posts, floor and roof systems — the skeleton.
Do you replace rotted beams?
Yes, including jack-and-replace under occupied homes.
Do you frame full additions?
We frame the structural shell; finish trades follow.
Do you work from engineer’s plans?
Always — stamped plans, correct hardware, inspected work.
Shoring
What is shoring?
Temporary structural support for a building or excavation during construction.
When is shoring required?
Whenever loads must be carried while foundations/soil are altered — lifts, dig-outs, deep excavations near structures.
What is a soldier pile wall?
Driven or drilled vertical steel piles with lagging retaining soil at excavations.
Do you do residential and commercial shoring?
Both — houses are our specialty; we shore for GCs too.
Still have a question about your house?
Free site visit, honest assessment, written estimate — often the same day you call. Ask for Jeff.