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King County, Washington
Construction Materials Testing in King County, WA
Concrete, soil, and aggregate testing in King County, Washington — fresh concrete tests and cylinder breaks, Proctor and nuclear density, gradation, Atterberg limits, and soil corrosivity — by ACI- and NICET-certified technicians, with results reviewed and issued under a documented quality system.
- Dispatched from
- Seattle, WA regional hub · project-based staffing
- Lead time
- Scheduled by phone or proposal; lead time confirmed when the scope is set
- Laboratory
- Sugar Land, TX laboratory under chain of custody, or a mobile laboratory for large projects
- Reporting
- Reviewed and issued under a documented quality system; formatted for owner, engineer, and building-official review
- Serving
- King County, WA — Seattle, Spokane, Tacoma
- Coverage
- Washington statewide · 27 regional hubs
- Technicians
- ACI Grade I · NICET CMT · ICC special inspectors
- Call us
- (346) 420-5425
Scope
What we test in King County
Concrete testing services
Fresh concrete sampled and tested at the pour — slump, air content, unit weight, and temperature — with cylinders and beams cast on site and broken in the laboratory on the schedule your specification calls for.
ASTM C172ASTM C143ASTM C231ASTM C173ASTM C138ASTM C1064ASTM C31ASTM C39
Aggregate testing services
Gradation, fines content, specific gravity and absorption, unit weight, abrasion resistance, and stockpile moisture for concrete, base course, and backfill aggregates.
ASTM D75ASTM C136ASTM C117ASTM C127ASTM C128ASTM C29ASTM C131ASTM C566
Soil compaction and density testing
Standard and modified Proctor curves in the laboratory and in-place density by nuclear gauge on every lift, so fill, subgrade, and trench backfill are documented against the specified percent compaction.
Soil classification and index testing
Sieve and hydrometer gradation, Atterberg limits, moisture content, specific gravity, and USCS classification for earthwork acceptance, select-fill verification, and geotechnical reports.
ASTM D6913ASTM D7928ASTM D1140ASTM D4318ASTM D2216ASTM D854ASTM D2487
Soil corrosivity testing
pH and electrical resistivity of backfill for MSE walls, pipelines, and buried structures, reported against the specification limits for metallic and geosynthetic reinforcement.
Special inspection (IBC Chapter 17)
ICC-certified special inspectors for reinforced concrete and soils, reporting to the building official alongside the materials test results, so one agency covers both requirements.
Full scope, standards list, and pricing basis: Construction Materials Testing.
Local conditions
Construction materials testing conditions in King County
King County sits on a complex mix of glacially consolidated soils, alluvial deposits, and weathered bedrock that behaves differently lot by lot — and wet Pacific Northwest winters mean concrete placement windows and compaction opportunities demand more discipline than in drier climates. From light rail extensions and arterial reconstruction to mid-rise timber-frame and concrete developments across Seattle, Bellevue, Renton, and surrounding municipalities, construction here moves fast and involves agencies that require documented, defensible materials data. Our Seattle regional hub dispatches ACI- and NICET-certified technicians throughout King County for ASTM-compliant field and laboratory testing of concrete, aggregate, and soil. Fresh concrete testing, cylinder breaks, Proctor compaction, nuclear density, aggregate gradation, soil classification, and soil corrosivity testing are all performed under a documented quality system that produces reports prepared for third-party review.
Glacially overridden soils common across King County — including dense glacial till and softer interbedded lacustrine deposits — can vary significantly within a single site, making soil classification and compaction verification particularly important for subgrade acceptance. Cool, rainy conditions from fall through spring affect concrete set times and evaporation rates, and ASTM C1064 temperature monitoring and ACI 306 cold-weather concrete protocols are relevant considerations on many King County placements.
FAQ · King County
King County has a long rainy season — how does wet weather affect when and how you perform compaction testing?
Moisture content is the controlling variable in compaction work. We run ASTM D698 or D1557 Proctor tests to establish the moisture-density relationship, then verify field density by nuclear gauge per ASTM D6938. In wet Pacific Northwest conditions, soils frequently arrive or become over-optimum in moisture; our technicians document in-place moisture alongside density so the geotechnical engineer of record has the data needed to accept or reject the lift — rather than guessing.
Seattle-area projects often involve deep fills or structural embankments over soft ground. Can you support density testing on those applications?
Yes. For fills over compressible or variable subgrades — common where lacustrine or alluvial soils are present in lower-lying parts of King County — we perform nuclear density testing per ASTM D6938 at frequencies your specifications require, document test locations by station or grid, and flag failing lifts in real time. Reports reference the Proctor curve on file so every field test is traceable to a lab-established standard.
What concrete tests are typically required by Washington State DOT or King County agency specs on public work?
Most public agency specifications in Washington reference ASTM and ACI test methods directly. Standard field testing on fresh concrete includes ASTM C172 sampling, C143 slump, C231 air content, C1064 temperature, and C138 unit weight, followed by cylinder fabrication per ASTM C31. Compressive strength is measured per ASTM C39. Our ACI-certified technicians perform and document each procedure to satisfy contractor submittals, special inspection programs, and agency quality records.
How fast can a technician be on site in King County?
King County work is dispatched through our Seattle, WA regional hub. Scheduled visits are set up by phone at (346) 420-5425; multi-day placements and full-time project assignments are scheduled through a proposal request.
Which office covers materials testing in King County, WA?
Field work in King County is dispatched through the Seattle, WA regional hub. Laboratory testing is performed in Sugar Land, TX under chain of custody, or in a mobile laboratory mobilized to large King County projects.
Are the technicians you send to King County certified?
Yes. Concrete technicians hold ACI Concrete Field Testing Technician Grade I; soils and laboratory technicians hold NICET Construction Materials Testing certifications; special inspection is performed by ICC-certified special inspectors. Where Washington agencies or owners require state-specific certifications, those are confirmed in the proposal.
Scheduling & proposals
Need construction materials testing in King County?
Call to schedule a technician, or send project documents for a written proposal.