Apprentice Tips: Common Plumbing Mistakes and How to Avoid Them

Skipping the Pipe Prep

When working with copper or plastic, it's crucial to properly prepare the pipe ends. That means:

• Cutting straight with a pipe cutter

• Deburring the edges

• Cleaning copper thoroughly before soldering

• Using inserts for plastic pipes when needed

Rushing this stage can lead to poor seals, leaks, or fittings that fail under pressure.

Overtightening Compression or Threaded Joints

It’s a natural instinct to want everything tight and secure but overtightening can damage threads, crush olives, or crack fittings. This is especially common with brass or plastic connections.

Tip: tighten until firm, then an extra quarter-turn is often enough. If you’re unsure, ask someone experienced or refer to the manufacturer’s guidance.

Mixing Incompatible Materials

Joining copper and galvanised steel without the correct fittings can cause corrosion through electrolysis. Similarly, using the wrong sealant on certain plastics can degrade the material over time.

Always check compatibility not just for fittings, but for sealants, jointing compounds, and pipe types.

Forgetting to Pressure Test

It’s easy to assume everything’s fine once a system is fitted, but pressure testing should always be done before boxing anything in or finishing a job. It’s one of the most important checks for leaks, especially in closed systems.

Tip: Use the correct testing equipment and don’t rush. Even if it feels like an extra step, it’s better than a callback later.

Not Asking Questions

This isn’t a technical mistake but it’s a common one. Apprentices sometimes avoid asking questions to avoid looking inexperienced, but the best tradespeople never stop learning. If something doesn’t look right or feel right, check it. It could save you a lot of time and build your confidence.

Stay Curious, Stay Safe

Plumbing is a skilled trade that rewards patience, precision, and a willingness to learn. Everyone starts somewhere and every mistake avoided is a step closer to becoming a professional that people trust.

If you're unsure about a fitting, sealant, or tool for the job, pop into Collister and Glover or give us a ring. Our team has decades of experience and we’re always happy to offer advice or point you in the right direction.