Here are the most common plumbing mistakes in DIY remodels and tips on how to avoid them.
1. Ignoring Local Plumbing Codes and Permits
Many DIYers jump right into plumbing work without checking local codes or obtaining necessary permits. This can lead to failed inspections, fines, and having to redo work.
How to Avoid:
- Always research your local plumbing code requirements before starting.
- Obtain permits if required.
- Consider consulting a professional plumber for complex tasks.
2. Using Incorrect Pipe Materials
Choosing the wrong type of pipe or fittings can cause leaks, poor water pressure, or system failure.
Common Errors:
- Using PVC for hot water lines (PVC isn’t rated for hot water).
- Mixing incompatible pipe types without proper connectors.
How to Avoid:
- Use CPVC, PEX, or copper for hot water lines.
- Use proper transition fittings when connecting different materials.
3. Improper Pipe Slope and Drainage
Drain pipes need to slope correctly (typically ¼ inch per foot) to ensure waste flows freely. Poor slope causes slow drainage and clogs.
How to Avoid:
- Use a level when installing drain pipes to maintain proper slope.
- Test drainage with water before closing walls or floors.
4. Incorrect Venting
Plumbing vents prevent sewer gases from entering your home and allow drains to function properly.
Common Mistakes:
- Omitting vents or improper vent placement causes slow drains and odors.
How to Avoid:
- Follow venting guidelines precisely or consult a plumber.
- Use air admittance valves (AAVs) where code allows.
5. Overtightening Fittings
Trying to tighten fittings too much can crack pipes or strip threads, causing leaks.
How to Avoid:
- Hand-tighten fittings and then use a wrench for a quarter turn.
- Follow manufacturer’s torque recommendations.
6. Failing to Shut Off Water Properly
Forgetting to shut off the main water supply or neglecting to install shut-off valves at fixtures can cause flooding.
How to Avoid:
- Always shut off water before starting work.
- Install individual shut-off valves on sinks and toilets.
7. Skipping Pressure Testing
Not pressure testing your plumbing before sealing walls can hide leaks that cause water damage.
How to Avoid:
- Use pressure gauges to test for leaks before finishing walls.
- Fix any leaks immediately.
8. Using the Wrong Tools
Using improper plumbing tools increases the chance of damaging pipes or fittings.
How to Avoid:
- Invest in or rent the right tools like pipe cutters, deburring tools, and plumbing wrenches.
- Watch tutorials to learn proper techniques.
Final Thoughts
Plumbing is a technical and code-driven part of any remodel. While DIY plumbing can save money, mistakes can quickly add up in repair costs and delays. When in doubt, don’t hesitate to hire a professional plumber for complex tasks or inspections.