Concrete Slabs in Bellevue, WA
Need a garage, shed, ADU or hot tub slab in Bellevue? Here’s how we size the base and slab, typical prices, and what to send for a quote.
- Base and compaction sized to the load
- Vapor barrier and thickened edges where needed
- Flat or sloped to drain, as the use needs

Get a slab quote in Bellevue
Tell us about the project. We’ll call or email to talk it through.
Concrete Slabs for Bellevue properties
A slab is the simplest thing we pour and the easiest to get wrong. Flatness, thickness, base and edges change with what sits on it: a hot tub, a car, a shed, or a living space. We start with the use and the soil, then size the slab to match.
Ranch houses, split-levels, and large new homes on rebuilt lots. Rebuilds often need new driveways, walks, and patios all at once. We work across West Bellevue, Somerset, Newport Hills, Factoria, Lake Hills, Crossroads, Bridle Trails, Woodridge and Eastgate.
Garage slabs
Thickened edges, reinforcement and a slope toward the door.
Shed and studio pads
Level pads sized for the building.
ADU and cottage slabs
Slab-on-grade foundations poured to plan.
Bellevue conditions that affect your slab
Soil and settling
Most of Bellevue sits on glacial till that compacts well, but cut-and-fill lots from the 1960s and 70s subdivisions can hide loose fill. Wet pockets show up near creeks and at the base of slopes.
Yards and access
Lots are often larger than in Seattle, which leaves room for bigger patios and better truck access, but long driveways and slopes still mean careful planning for drainage.
Rain and drainage
Rain off big roofs and long driveways has to go somewhere. Trench drains at the garage and sloping walks away from the house are common asks.
Details that help us price your slab in Bellevue
You don’t need answers to all of these. They’re the questions that shape the design and the price.
Use
Garage, shed, ADU, hot tub or equipment.
Size
Length, width and any plans.
Site
Photos of the area, slope and access.
Existing
An old slab, pavers or lawn to remove.
Permit
Is it part of a permitted building?
Timing
When the building or tub arrives.
Options to talk through
| Slab | Typical use | Keep in mind |
|---|---|---|
| Utility / shed slab | Sheds, bins, equipment | Simple base and broom finish |
| Garage slab (monolithic) | Garages and carports | Thickened edges, rebar grid, vapor barrier |
| Slab-on-grade foundation | ADUs and additions | Built to plans and inspected |
| Hot tub pad | Spas | Flat and reinforced for heavy point loads |
Permits for concrete slabs in Bellevue
Foundations and slabs for additions, garages, ADUs and other buildings are part of the building permit, with inspections of footings and steel before the pour. Bellevue Development Services makes the call for your property, and we’ll tell you what we expect before you commit.
Planning a new slab in Bellevue?
Call to talk it through, or send a few details and photos.
What concrete slabs typically cost in the Seattle area
Ballpark numbers help you plan a budget before anyone visits. Use them as a starting point, not a promise.
| Slab | Typical range |
|---|---|
| Basic utility or shed slab | from about $5 per sq ft |
| Garage slab (monolithic) | from about $7 per sq ft |
| Slab-on-grade with base, vapor barrier and rebar | $6–$14 per sq ft |
Typical market ranges, not a quote from Seattle Concrete Contractors. These are ranges other Seattle-area concrete contractors publish for this work (Seattle-WA-Concrete and Seattle Concrete (seattleconcrete.com) published price guides, checked November 2026). Your price depends on size, access, removal, base work, finish and permits, and on conditions at your Bellevue property. We give a written quote after we understand the job.
Concrete Slabs in Bellevue: quick answers
How thick should a slab be?
It depends on the use: shed pads are thinner than garage floors, and structural slabs follow the plans.
Do I need a permit for a slab?
Slabs for garages, ADUs and enclosed buildings are part of a building permit. Simple pads and patios often aren’t.
Do I need a vapor barrier?
Under anything enclosed, yes. Outdoors, it depends.
Do I need a permit for concrete work in Bellevue?
Many like-for-like patios and walks don’t, but retaining walls over 4 ft from the bottom of the footing, work on steep slopes or other critical areas, and anything in the street right-of-way usually do. Bellevue Development Services decides for your address.
Learn more about concrete slabs
See the full concrete slabs guide, or all concrete services in Bellevue.
More concrete services in Bellevue
Tell us about your project
A few photos and rough measurements are enough to start. If you’re not sure what the job needs, describe the problem and we’ll talk it through.
Call (206) 566-0528 or use the quote form at the top of this page.
Find us on Google Maps
Seattle Concrete Contractors | (206) 566-0528 | Seattle, WA