- Skipping water hammer arrestors – Always install dedicated arrestors near fast-closing valves (toilets, washing machines) to prevent pipe knocking.
- Reusing flexible hoses – Replace hoses every 5 years or when damaged; old hoses can fail and cause leaks.
- Using lead solder – Only use modern 95/5 tin-antimony solder for potable water; lead solder is banned.
- Not deburring pipes – Remove burrs after cutting to maintain proper water flow and prevent premature pipe wear.
- Dirty pipes/flux – Clean pipes and use uncontaminated flux before soldering to ensure leak-free joints.
- Insufficient pipe support – Add hangers every 6 feet for ½–¾” copper to prevent joint stress and damage.
- Wrong Teflon tape/pipe dope order – Apply tape first, then pipe dope for a secure, leak-free connection.
- Cross-threading fittings – Start connections by hand, ensure threads align, then tighten with a wrench to avoid leaks.