If you’ve had plumbing work done recently, you’ve probably heard your plumber mention copper vs PEX in London Ontario. Homeowners often ask which one is better, and the honest answer is that it depends on where the pipe is going. At Triton Home Service, we use both copper and PEX every week, and each one earns its place for different reasons.
Why We Use PEX-A for Most Water Lines
For rough-in work and any water line that ends up hidden inside a wall or floor, we reach for Uponor PEX-A. It installs faster than copper, which keeps labour costs down, and it has a slight R-value that copper simply doesn’t. That matters more than people expect: PEX-A resists condensation and sweating far better than copper does, which means less risk of hidden moisture damage inside your walls over time.
When We Still Choose Copper
Speed and cost aren’t the only things that matter. If a pipe is going to be visible, whether that’s an exposed run in a basement or a finished mechanical room, copper still wins on appearance. It also holds up better against mechanical damage, so anywhere a pipe is exposed to impact or wear, copper is the safer choice.
Fire Rating and Code
Both materials are fire-rated for residential use under 1 inch in diameter, so that’s rarely the deciding factor in a home. Above 1 inch, code requires copper, but that size of water line is uncommon in a typical London area house.
One Place PEX-A Can’t Go
PEX-A cannot be exposed to UV light, so it’s never used outdoors or anywhere it will see direct sunlight. Copper doesn’t have that restriction, which is another reason we’ll choose it for exterior or sun-exposed runs.
A Detail Most Plumbers Won’t Mention
Code requires PEX-A to be supported every 3 feet, more often than copper needs. When we’re running PEX to the top of a water heater, we use a Caleffi mixing valve instead of a Watts-style valve. It lets us run straight elbows right to the wall without supporting a heavy brass fitting mid-run, which makes for a cleaner, more secure install.
And if you’re wondering about mixing the two materials in one system, that’s completely fine. Many homes in London and St. Thomas have both copper and PEX-A working together without any issue.
A Quick Note on PEX-A vs. PEX-B
Not all PEX is the same. We install PEX-A because it’s a more resilient product with more installation options than PEX-B. We’ll cover exactly why in a dedicated post soon, so watch for that if you want the full comparison.
Frequently Asked Questions
Is PEX-A as durable as copper?
Yes, for residential water lines under 1 inch, PEX-A is fire-rated and code-approved the same as copper, and it resists condensation better.
Can copper and PEX-A be connected in the same system?
Yes. Mixing the two materials is standard practice and doesn’t cause any compatibility issues.
Why do you choose PEX-A over copper for most jobs?
Cost and install speed are the main factors, along with PEX-A’s resistance to sweating in hidden wall cavities.
Can PEX-A be used outdoors?
No. PEX-A cannot be exposed to UV light, so copper is used for any exterior or sun-exposed water line.
How often does PEX-A need to be supported?
Code requires support every 3 feet, more frequently than copper.
If you’re planning a renovation or repipe and aren’t sure which material is right for your project, contact Triton Home Service for a straightforward answer based on your specific home. Or book a free estimate online anytime
About the Author
Aron Oretan is the owner of Triton Home Service, a Red Seal Plumber and Red Seal Steamfitter with over 26 years in the trade. He holds the RSE designation and has spent five years teaching at Fanshawe College. Triton serves London, St. Thomas, and the surrounding Southwestern Ontario region with residential service, renovations, and ICI new construction
