For most full-home repipes, PEX is the practical choice: lower material and labour cost, strong freeze resistance, and fewer joints to fail. Copper still earns its place where exposed metal runs, very high-temperature service, or a homeowner's preference for metal matters. Aggressive water chemistry or a planned full-home renovation can tip the decision either way, which is why we always start with a site assessment before recommending one material over the other.
TL;DR:
- PEX is generally more affordable and easier to install in tight spaces or areas prone to freezing, thanks to its flexibility and low material costs.
- Copper pipes last several decades but are more prone to corrosion in aggressive water chemistry and can burst in freezing conditions due to rigidity.
- Proper installation is crucial for both materials; PEX needs clamps for expansion, while copper requires slack in bends to handle thermal movement.
- Water quality tests can determine if copper leaching might occur, especially in low pH or stagnant water conditions, affecting safety and aesthetics.
- Site assessment, water chemistry, and homeowner preferences should guide the choice, with PEX favored for cost and freeze resistance and copper for exposed or high-temperature applications.
Table of Contents
- PEX and copper: pros and cons side by side
- What PEX and copper cost to install in a renovation
- How long each material lasts and how it handles freezing
- Is copper or PEX safer for your drinking water?
- Codes and certifications to check before you buy
- When to choose PEX and when to choose copper
- How we handle material selection during a renovation
- A builder's take on the PEX vs copper decision
- Let us manage your repipe during the renovation
- FAQ
- Sources
PEX and copper: pros and cons side by side
PEX and copper solve the same problem in different ways, and each has a short list of real strengths and real weaknesses.
PEX advantages:
- Flexible tubing snakes through joists and tight stud bays with far fewer fittings than rigid pipe.
- Material and labour costs typically run lower because installers cut fewer joints and work faster.
- Elasticity and low thermal conductivity give it strong resistance to splitting when water inside freezes.
Copper advantages:
- Rigid metal pipe holds up to decades of mechanical wear and handles very high water temperatures without softening.
- Scrap copper retains value and is widely recyclable at end of life.
- Exposed runs look finished without extra cladding, which some homeowners prefer for visible plumbing.
Two common PEX types show up on renovation sites: PEX-A, which is more flexible and expands slightly for certain fitting systems, and PEX-B, which costs a little less and is more rigid. Both perform well when installed to the manufacturer's instructions. A persistent myth claims PEX degrades quickly indoors, but PPI's plumbing design and installation guide documents lifecycle performance data supporting long service life when the pipe is shielded from UV exposure during storage and installation.
What PEX and copper cost to install in a renovation
PEX usually lowers both material and labour costs because a plumber can run coiled tubing from a central manifold to each fixture, cutting the number of joints and the hours spent soldering. Copper requires more individual lengths, elbows, and tees, each one a potential leak point and each one adding time.
Joining methods differ enough to affect your schedule:
- Copper uses soldering (with an open flame) or flare fittings, both of which demand careful technique and fire-safety precautions in finished spaces.
- PEX uses expansion fittings, crimp rings, or press connections, all completed with hand tools and no open flame.
Because PEX work involves no torch, it is often faster in occupied homes and reduces fire-watch requirements during a renovation. Both materials require a licensed plumber for code-compliant work and a permit through your municipality. We do not recommend DIY repiping on a full-home project, since a failed joint behind finished drywall is far more expensive to fix than it is to prevent.
How long each material lasts and how it handles freezing
Copper pipe commonly lasts several decades, but it can fail earlier through pinhole leaks caused by corrosion, especially in areas with aggressive water chemistry. PEX's main failure modes are different: UV degradation from prolonged sun exposure before installation, and mechanical damage from kinks or improper support.
Cold climates are where the two materials diverge most. PPI's technical report on freeze resistance notes that PEX conducts heat far less efficiently than copper and stretches rather than splits when the water inside freezes. Copper, by contrast, is rigid and prone to bursting under the same conditions. Proper installation still matters for both: PEX needs clamps spaced to allow for expansion and support that prevents sagging in long runs, while copper needs enough slack in tight bends to absorb thermal movement without stressing joints.
Is copper or PEX safer for your drinking water?
Health Canada sets a maximum acceptable concentration for copper in drinking water at 2 mg/L, with an aesthetic objective of 1 mg/L; above the aesthetic threshold, water can develop a metallic taste or stain fixtures blue-green. Copper at the tap comes mainly from the corrosion of plumbing itself, not from the water source.
Certain water conditions raise the risk of leaching:
- Low pH or specific alkalinity ranges make water more corrosive to copper pipe.
- Water sitting still overnight or longer, such as in a first-morning draw, picks up more copper than water that has been recently run.
If you notice staining or a metallic taste, running the cold tap for a minute before use is a simple mitigation, and testing a first-litre sample can confirm whether levels exceed the aesthetic objective.
PEX raises different questions. Products carrying a CCMC evaluation meet CAN/CSA-B137.5 standards for potable water use, and homeowners should ask suppliers for that certification when sourcing tubing and fittings.
Codes and certifications to check before you buy
Copper has long been accepted under the National Plumbing Code, backed by decades of field performance. PEX systems gain acceptance through CCMC evaluation reports and compliance with CAN/CSA-B137.5. Before signing off on a product, ask your supplier for the CCMC number, the relevant CAN/CSA reference, and the manufacturer's installation guide, since CCMC approvals often come with specific installation conditions that your installer needs to follow exactly.
When to choose PEX and when to choose copper
Some renovation conditions point clearly toward one material or the other.
- Choose PEX when access is tight, the run has many turns, or the budget is constrained.
- Choose PEX in freeze-prone areas like unheated basements, garages, or cottage country.
- Choose copper for exposed runs where appearance matters or where water temperatures run unusually high.
- Choose copper if you simply prefer a metal system and value its recyclability at end of life.
Before finalizing a decision, ask your plumber about local water chemistry, any visible staining in existing fixtures, and whether older solder joints in your home might contain lead.
Pro Tip: Request a water test before repiping decisions; it costs little and settles the copper-versus-PEX question faster than any brochure.
How we handle material selection during a renovation
When we take on a full-home renovation, we start by inspecting the existing plumbing and flagging any visible corrosion, staining, or outdated materials. We review water-quality considerations with you, walk through costed options for PEX and copper, and explain how each choice affects your schedule. Repiping during a gut renovation adds manageable time to the mechanical phase since walls are already open, which is far less disruptive than repiping a finished home. You can see how this fits into the broader project on our renovation process page, and our about page outlines who manages that process from start to finish.
A builder's take on the PEX vs copper decision
My own priority order is simple: confirm water chemistry first, then weigh cost and access, then decide. Most homes do fine with PEX, but I never skip the water test before recommending it.
— Cory
Let us manage your repipe during the renovation
We handle material selection, code compliance, and scheduling as part of every full-home renovation we take on, so you are not left comparing pipe specs on your own. Before your first consult, it helps to have:
- Rough floor plans or a sense of your layout
- A general budget range in mind
- Any known water quality concerns, like staining or taste
Reach out through our contact page to set up an initial assessment and get a straight answer on what your home needs.
FAQ
What are the disadvantages of PEX plumbing?
PEX can degrade if exposed to direct sunlight for long periods before or during installation, and it is more vulnerable to mechanical damage like kinks or rodent chewing than rigid metal pipe. It also cannot be used for exterior gas lines or in some very high-temperature applications where copper is standard.
What is better to use, PEX or copper?
PEX is usually the better choice for cost, freeze resistance, and ease of installation in a typical home repipe, while copper remains preferable for exposed runs or very high-temperature service. The right answer depends on your water chemistry, budget, and how the pipe will be used, which is why a site-specific assessment matters more than a blanket rule.
Why is copper piping no longer used?
Copper is still accepted under the National Plumbing Code and remains in active use, so it has not been phased out. It has become less common in new installations mainly because PEX typically costs less to install and resists freeze damage better in cold climates.
Can you bury PEX directly in the ground?
PEX used for buried service lines needs proper bedding and protection from sharp or unstable soils, along with approved sleeves where it passes through concrete. Skipping this preparation is a common cause of premature failure in buried PEX installations.
Sources
- Copper in drinking water — Health Canada
- Evaluation report — AquaPEX/hePEX (CCMC 13529-R)
- PEX plumbing design and installation guide (third edition) — PPI