DIY plumbing can save you time and money — until it doesn’t. At Merinal, we’ve spent over 45 years helping homeowners and tradespeople get the job done right the first time. Whether you’re changing a tap, replacing pipework, or fitting a new shower, avoiding these common mistakes can save you leaks, stress, and repeat visits to the hardware shop.
1. Overtightening Joints and Fittings
More pressure doesn’t always mean better sealing. In fact, overtightening compression or threaded fittings can crack nuts, deform washers, and even damage plastic pipework — leading to slow leaks or sudden failure.
🛠 Merinal Tip: Tighten firmly, then give a quarter turn more — or use tools with torque settings for delicate parts.
2. Mixing Different Pipe Types Without the Right Connectors
Copper, plastic, and push-fit pipework all behave differently. You can’t just jam them together — and forcing it usually causes trouble. You need the correct adaptors, inserts, and sealants for a safe and legal join.
3. Skipping Isolation Valves
If you’re replacing a tap or fixing a leak, an isolation valve lets you cut off water locally instead of shutting down the whole house. DIYers often forget these — and regret it later.
🛠 Merinal Tip: Tighten firmly, then give a quarter turn more — or use tools with torque settings for delicate parts. Always fit isolation valves on hot and cold feeds when doing any fixture work. They’re cheap insurance against future problems.
4. Not Testing for Leaks Properly
The job’s not finished until you’ve tested under pressure. Some DIYers forget to check for slow weeps or drips. Others test too early — before sealant has cured or joints are fully tightened.
Best Practice:
- Wipe every connection dry.
- Turn on water slowly and check each joint.
- Leave a dry tissue under pipework overnight for hidden drips.
5. Using the Wrong Sealant (or None at All)
Not all joints need the same kind of seal. Some DIYers use PTFE tape where they shouldn’t — or forget it entirely. Others reach for silicone where a rubber washer or thread sealant is required. This can lead to slow leaks or total joint failure.
🛒 Stock up at Merinal:
We carry a full range of PTFE tapes, jointing compounds, and silicone sealants — if you’re unsure what your job needs, speak to a member of our experienced team.
Conclusion
DIY plumbing can be hugely satisfying — but only when it’s done right. The most common issues, like overtightening fittings, skipping isolation valves, or using the wrong sealant, often come down to small oversights. With a bit of planning and the right materials, you can avoid costly mistakes and get professional results.
At Merinal, we’re here to help — whether you need advice on what product you need, the right connector for that awkward pipe, or a last-minute part before the weekend. We’ve got your plumbing, heating, and electrical products in stock and ready to go, and our team knows exactly how (and where) to use them.
Pop into our Leigh branch or browse online and make your next DIY job a success from the start.
