Ontario Building Code 2024: Essential Guide to PEX, PVC, and CPVC Piping Standards
Sarah's Expert Insight
OBC Compliance Specialist
"Choosing between PEX and CPVC is more than a preference; it is a technical decision based on the specific thermal and pressure demands of a project in regions like London or Muskoka. At empcontracting.ca Inc. your construction contractor in London, Ontario, we emphasize that while PVC is cost-effective for cold-water mains, the strict 82°C/690 kPa limit for CPVC must be carefully managed in high-demand residential builds to prevent system failure."
When planning a plumbing installation in Ontario, adhering to the 2024 Building Code Compendium is non-negotiable. As empcontracting.ca Inc. your construction contractor in London, Ontario, we prioritize compliance to ensure the safety and longevity of your potable water and drainage systems.
7.2.5.6. Crosslinked Polyethylene (PEX) Piping
Crosslinked polyethylene, commonly known as PEX, is a staple in modern construction. According to OBC 7.2.5.6, PEX pipe and its manufacturer-approved fittings must conform to CSA B137.5. This standard applies to both hot and cold potable water systems, ensuring pressure ratings are maintained under varying thermal conditions.
7.2.5.7. Polyvinylchloride (PVC) Pipe and Fittings
PVC is widely used for cold water applications, but strict rules apply under Section 7.2.5.7:
- Compliance: Must meet CSA B137.3 or CSA B137.2.
- Pressure Rating: Must have a pressure rating of at least 1,100 kPa.
- Schedule Standards: Fittings must conform to ASTM D2466 (Schedule 40) or ASTM D2467 (Schedule 80).
Critical Limitation: PVC and Hot Water
It is important to note that PVC water pipe and fittings shall not be used in hot water systems. For high-temperature applications, contractors must pivot to CPVC or PEX.
7.2.5.8. Chlorinated Polyvinylchloride (CPVC) Systems
CPVC is designed for both hot and cold water distribution. Under OBC 7.2.5.8, these systems must conform to CSA B137.6. The code provides a specific table for maximum permitted pressures based on water temperature:
| Max Temperature (°C) | Max Pressure (kPa) |
|---|---|
| 10°C | 3150 kPa |
| 40°C | 2100 kPa |
| 70°C | 1000 kPa |
| 82°C | 690 kPa |
7.2.5.9. Plastic Pipe for Underground Use
For drainage and sewer systems located underground—whether outside or beneath a building—specific standards apply to ABS, PVC, and PE piping. Standards include ASTM F628 for ABS with a cellular core and CSA B182.1 for plastic drain and sewer pipes. Choosing the correct material is vital for resisting soil pressure and environmental degradation.
Disclaimer: This content is generated from the Ontario Building Code for educational purposes. Always consult with a licensed professional engineer or your local building department before starting any construction project in London, Ontario.