Supply pipes
| Material | Look | Era | Notes |
|---|---|---|---|
| Lead | Matte grey; a key scratch shows bright metal | Very old homes | Health concern; replace |
| Galvanized steel | Grey with threaded fittings | Early to mid 20th century | Rusts inside, reduces flow |
| Copper | Orange-brown, soldered joints | 1950s to 2000s | Durable; pinholes with age |
| Polybutylene | Grey plastic, often with crimp rings | Late 1970s to 1990s | Fitting failures; consider replacing |
| PEX | Red, blue or white flexible plastic | 2000s onward | Flexible, freeze-tolerant |
Field note. To test for lead, scratch the pipe gently with a key. Lead is soft and shows a bright silver mark. A magnet does not stick to lead or copper but does to steel.
Drain pipes
- Cast iron. Heavy, black, very quiet. Common in older stacks and under-slab drains. Rusts and cracks with age.
- Clay. Used in older sewer laterals. Short sections with many joints, vulnerable to roots.
- ABS. Black plastic, standard in Ontario homes since the 1970s.
- PVC. White plastic, used for some drains and many sewer laterals.
- Bituminous fibre. Rare, used in some laterals mid-century. Deforms over time.
Mixing materials
Joining different metals can cause galvanic corrosion. Dielectric unions or appropriate transition fittings prevent it. When we repair one section, we use transitions suited to the materials on both sides.
What to do with this knowledge
If you have lead, polybutylene, or heavily corroded galvanized pipe, plan for replacement. See repiping and water line replacement.