Here’s What Civil Engineers Need to Know
If you’ve felt overwhelmed by the sheer number of plastic “crate-style” underground detention and retention systems appearing in the Canadian market, you’re not alone. Over the last few years, Canada has seen an explosion of crate manufacturers and “new” proprietary modular systems, many with drastically different quality levels, testing rigor, and long-term performance reliability.
And there’s a reason for this sudden flood in the market.
Why Are There So Many Systems in Canada?
Unlike Europe, the U.S., or other regions with established polymeric subsurface storage standards, Canada currently has no unified national standard for consultants to reference when evaluating plastic crate-style stormwater systems.
Because of this regulatory gap, any supplier can present a crate system, claim it “meets loading requirements,” and, on the surface, many of these products appear acceptable. As long as a vendor can provide some form of data or loading numbers, many systems end up being approved simply because there is no standard requiring more.
But this comes with significant engineering risk.
The Hidden Danger: Not All Crates Are Created Equal
Without a Canadian standard, the industry is seeing:
- Misleading test claims
Some suppliers claim “third-party testing,” but never state which standard they were tested to, or whether testing was performed on the full assembly with actual installation conditions. - Photo-edited test imagery & unverifiable data
In the example image below (taken directly from a supplier brochure), the crate system has been digitally photo shopped/ inserted into a load-testing machine. The vendor claims the system has been “third-party validated,” yet provides no reference to the testing protocol, failure criteria, sample count, or test conditions.
Such manipulation creates a dangerous illusion of reliability.
- Systems with insufficient long-term creep resistance
Plastic stormwater structures must withstand sustained loads over decades. 75 years design life and 5-year warranty is min. standard around the world. Many low-cost crates on the market have inadequate data on creep behavior, burial depth limits, or factor-of-safety methodology. - False equivalency between crate designs
Consultants are often told “all crates are the same,” when structural geometry, ribbing, resin quality, weld/connection integrity, and geo-integration can vary drastically.
The Good News: Standards Are Coming
CSA Group – New Standard Under Development
Canada is finally addressing this gap.
CSA is developing a Polymeric Subsurface Stormwater Management Crate Standard.
CSA Project Description:
Polymeric subsurface stormwater management crates (New Standard) | CSA Public Review System
This upcoming standard will define:
- Minimum structural requirements
- Testing loads and protocols
- Creep performance
- Installation requirements
- Verification and certification pathways
Once released, it will become the benchmark for crate-style systems in Canada.
ASTM International – Crate Standard in Progress
ASTM is also developing a new specification addressing polymeric modular stormwater storage units.
ASTM Work Item (WK87431):
https://www.astm.org/work-items/wk87431.html
ASTM’s involvement will bring global testing consistency and allow engineers to compare systems more reliably across markets.
What You Can Do Now: How to Vet Crate Systems Before Approving Them
Until formal standards are published, engineers should establish stricter internal screening criteria. When reviewing shop drawings or structural test packages, ask:
Essential Vetting Questions
Does the product have credible international certification?
Look for any of the following internationally recognized certifications:
- BBA (UK)
- DIBt (Germany)
- CSTB (France)
- BENOR (Belgium)
These agencies have been certifying polymeric structures for decades and enforce some of the most rigorous testing protocols in the world—far beyond the simple “static load tests” commonly presented in Canada.
What test standard was used?
“Third-party tested” is not enough. Require clarity on:
- Test method (ASTM, EN, ISO, or other recognized protocols)
- Load levels
- Duration
- Creep testing method
- Factor of safety
- Backfill and cover assumptions
- Test sample quantity
- Full assembly vs. component testing
If none of this can be produced, that’s a red flag.
Does the documentation disclose the resin type and mechanical properties?
Engineering-grade polypropylene has predictable creep and deformation behavior.
Commodity plastics do not.
Is the system tested as installed (with geogrid, stone, and actual field conditions)?
Many failures occur not from vertical load, but from:
- Lateral surcharge
- Poor base preparation
- Improper compaction
- Unsupported sidewalls
Systems should demonstrate testing under realistic field constraints, not isolated lab conditions.
Is the supplier transparent about manufacturing location, QA/QC, and traceability?
You should be able to obtain:
- Batch-specific QC data
- Resin traceability
- Manufacturing certifications (ISO 9001, etc.)
If not, proceed cautiously.
If you’d like to discuss how these changes will affect design practice, specifications, and supplier evaluations, I’m happy to walk you through it.
