What is PEX piping?
PEX (cross-linked polyethylene) is a flexible plastic tubing used for hot and cold water distribution in residential plumbing systems, replacing copper pipe in many modern Ontario homes.
Cross-linked polyethylene tubing, known as PEX, is a plastic water-supply line material that has become standard in Ontario residential plumbing over the past two decades. The cross-linking process chemically bonds the polyethylene molecules, giving the plastic durability and flexibility that rigid copper pipe cannot match.
PEX replaced copper in many Ontario homes for practical reasons. The material costs less, resists corrosion from acidic water chemistry common in regions with soft water, and installs faster because it bends to fit around obstacles without needing elbow fittings. Plumbers can run PEX through walls and under floors with fewer connection points, reducing labor time and potential leak locations.
The tubing comes in three color-coded varieties: red for hot water, blue for cold water, and white for either. This coding helps plumbers and homeowners identify line purpose at a glance during installation, maintenance, and leak detection and repair work. Most Ontario homes built since the early 2000s use PEX for at least some water supply runs, though some older properties or high-end installations may retain copper or use it alongside PEX.
PEX requires specific fittings and crimping tools to join sections, which means it is not a do-it-yourself replacement for existing copper runs. Licensed plumbers handle PEX installation to meet local Ontario building codes and warranty requirements.