A contractor excavating for a mid-rise on King Street North hit a layer of silty clay that looked fine but held water like a sponge. The gradation curve from our lab showed 48% passing the #200 sieve—way beyond what the preliminary borehole log suggested. That single sieve and hydrometer test changed the footing design from spread footings to a stiffer mat foundation, avoiding a potential differential settlement claim six months later. In Waterloo, where the overburden alternates between sandy till and glaciolacustrine silt pockets, the grain size distribution isn't just a classification exercise—it tells you how the soil will behave when saturated, frozen, or loaded. Our lab runs the full ASTM D422 curve, from coarse gravel down to clay colloids, because skipping the hydrometer portion in fine-grained soils is where most surprises originate.
In Waterloo's glacial terrain, 80% of foundation surprises come from fine-grained soils that looked like sand in the field but had 30% clay content in the hydrometer test.
Service characteristics in Waterloo Ontario
Risks and considerations in Waterloo Ontario
We've seen too many Waterloo projects where the grain size analysis stopped at the #200 sieve—no hydrometer, no clay fraction data—and the engineer ended up with a misleading 'silty sand' classification for what was actually a clayey silt. That gap matters. A soil with 25% clay content drains differently, consolidates differently, and reacts to frost differently than one with 8% clay, even if both are called 'silty sand' by a lazy classification. The Ontario Building Code's 2012 revision tightened the requirements for frost protection, and without a full hydrometer curve you can't properly apply the frost heave susceptibility tables. If your project is in the RIM Park area or anywhere east of the Conestoga Parkway where the Waterloo Moraine deposits are thicker, a truncated grain size analysis is a risk you don't need to carry into construction.
Our services
Our Waterloo lab provides grain size distribution testing as part of a broader geotechnical characterization package. Each service below supports specific design or compliance needs for projects across the Region of Waterloo.
Full Sieve + Hydrometer Package
Complete ASTM D422/D6913/D7928 analysis from 75 mm down to 0.001 mm. Includes gradation curve plot, Cu/Cc coefficients, and USCS classification per ASTM D2487.
Wash Sieve Only (Minus #200)
For sands and gravels where fines content is the primary concern. We wash the sample over a #200 sieve, dry, and report percent passing. Suitable for concrete aggregate checks under CSA A23.1.
Hydrometer-Only Analysis
For fine-grained soils where the coarse fraction is negligible. Sedimentation analysis per ASTM D7928 with temperature correction and meniscus reading. Delivers full silt/clay distribution curve.
Combined Geotechnical Suite
Grain size analysis bundled with Atterberg limits, natural moisture content, and organic content determination. Ideal for foundation design submittals requiring multiple index properties in one report.
Frequently asked questions
What is the cost for a grain size analysis (sieve + hydrometer) in Waterloo?
A full sieve plus hydrometer analysis per ASTM D422 typically ranges from CA$160 to CA$260 per sample, depending on whether we're testing a clean sand (fewer sieves, no hydrometer needed) or a silty clay requiring the full sedimentation procedure with multiple hydrometer readings over 24 hours. We'll confirm pricing when you tell us the soil type and project requirements.
How long does a sieve and hydrometer test take in your Waterloo lab?
Standard turnaround is 3 to 5 business days. The hydrometer portion alone requires readings at 0.5, 1, 2, 5, 15, 30, 60, 240, and 1440 minutes, so the sedimentation phase cannot be rushed. If you need results faster, we can prioritize the sieve fraction and follow up with the hydrometer data the next day.
Do I need the hydrometer test or is a simple sieve analysis enough?
If more than 10–12% of your sample passes the #200 sieve, you need the hydrometer. Without it, you're guessing at the silt/clay split, and that split controls drainage, frost susceptibility, and consolidation behavior. For Waterloo's silty till soils, we nearly always recommend the full analysis—skipping the hydrometer has led to misclassification on too many local projects.
What soil classification system do you use for grain size results?
We classify soils per ASTM D2487 (Unified Soil Classification System, USCS), which uses the grain size distribution and Atterberg limits to assign group symbols like SP, CL, or SM. For aggregate gradation related to concrete or asphalt, we can also report against CSA A23.1 or OPSS gradation bands if specified in the project requirements.