Concrete Slabs in Kent, WA
Seattle ConcreteCONTRACTORS
(206) 566-0528
Need a garage, shed, ADU or hot tub slab in Kent? 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 Kent
Tell us about the project. We’ll call or email to talk it through.
Concrete Slabs for Kent 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.
Mid-century homes downtown and on Scenic Hill, many 1970s through 2000s subdivisions on East Hill, and new homes and townhomes. We work across East Hill, West Hill, Panther Lake, Meridian, Lake Meridian, Scenic Hill, the Kent Valley and downtown.
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.
Kent conditions that affect your slab
Soil and settling
The Kent Valley is the old Green River floodplain, with softer river soils and a high water table in many areas. Slabs there need a solid compacted base and drainage that keeps water from sitting underneath.
Yards and access
Subdivision lots generally have good truck access. Fenced back yards and hillside lots can still need a pump or a longer wheelbarrow route.
Rain and drainage
Standing water on valley lots and runoff on hill lots are the two main ways concrete fails here. Slope and drains are planned on every job.
Details that help us price your slab in Kent
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 Kent
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. Kent’s Permit Center makes the call for your property, and we’ll tell you what we expect before you commit.
Planning a new slab in Kent?
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 Kent property. We give a written quote after we understand the job.
Concrete Slabs in Kent: 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 Kent?
Ground-level flatwork on private property is often exempt, while retaining walls over 4 ft from the bottom of the footing and work in the right-of-way need permits. Kent’s Permit Center processes permits online and can confirm for your address.
Learn more about concrete slabs
See the full concrete slabs guide, or all concrete services in Kent.
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