11 Common DIY Plumbing Mistakes (And How to Avoid Them)


Plumbing is one of those things that most people take for granted until something goes wrong. And when something does go wrong, it’s often a messy and expensive fix. In many cases, these problems could have been avoided if the homeowner had only known what not to do. Here are the most common DIY plumbing mistakes, and how to avoid them.

1. Not properly shutting off the water before beginning a repair.

This is perhaps the most common mistake made by inexperienced DIYers, and can often lead to catastrophic results. The reason you need to shut off the water before beginning any type of repair is that water can be very destructive. If you are working on a pipe or fixture and you don’t shut off the water first, you run the risk of causing serious damage to your home.

Tip: Make sure you know where your home’s main water shut-off valve is located, and that you know how to use it properly.

2. Failing to use the proper tools and techniques.

Many plumbing repairs require specialized tools and techniques that most people don’t have access to. Unless you’re absolutely sure you know what you’re doing, it’s best to leave these sorts of repairs to the professionals. Otherwise, you run the risk of making the problem worse or even causing serious injury to yourself.

Tip: If you’re not sure how to properly use a particular tool or technique, don’t be afraid to ask for help from someone more experienced.

3. Not properly securing pipes and fittings.

Loose pipes and fittings are one of the leading causes of plumbing leaks. When these parts are not properly secured, they can come loose over time and cause water to start leaking. This can often be a slow leak that goes undetected for a long period of time, causing extensive damage to your home.

Tip: Make sure all pipes and fittings are properly tightened before calling the job done. To do this, use a pipe wrench to grip the fitting and turn it clockwise until it’s snug.

4. Relying on store-bought chemicals to clear drains.

Many people think that store-bought chemicals are the best way to clear a clogged drain. However, these chemicals can actually do more harm than good. They are corrosive and can damage your pipes, and they can also be dangerous to humans and pets if used improperly.

Tip: The best way to clear a clogged drain is to use a plunger. If that doesn’t work, you can try using a plumber’s snake.

5. Attempting a repair without a permit.

In many jurisdictions, plumbing repairs require a permit from the local authorities. Attempting to do a repair without the proper permit can result in hefty fines, or even the need to completely undo the repair. Make sure you check with your local authorities before beginning any repair work.

Tip: To avoid the hassle of getting a permit, you can always hire a professional plumber to do the job for you.

5. Overtightening pipes

Most people think that if a little tightness is good, then more must be better. Unfortunately, this isn’t the case when it comes to plumbing. Overtightening pipes can actually damage the threads, making it more difficult to remove the pipe in the future. It can also lead to leaks. When tightening a pipe, stop as soon as you feel resistance.

Tip: Use a pipe wrench to grip the pipe and turn it clockwise until it’s snug, but don’t overdo it.

6. Sloping shower floor

A properly sloped shower floor will help to drain water towards the drain and prevent pooling. Many people make the mistake of not creating a proper slope, which can lead to water build-up and eventually leaks.

Tip: When creating a slope, make sure it slopes towards the drain at a rate of 1/4 inch per foot.

7. Improperly installed toilets

If a toilet isn’t installed correctly, it can cause all sorts of problems, from leaks to improper flushing. It’s important to make sure the toilet is properly secured to the floor and that all connections are tight and secure.

Tip: To properly install a toilet, you’ll need to use a wax ring to create a seal between the toilet and the flange. Once the toilet is in place, use bolts to secure it to the floor.

8. Not testing for leaks

Once a repair is complete, it’s essential to test for leaks. A simple leak can cause major damage if left unchecked, so it’s always best to err on the side of caution and check for leaks before calling the job done.

Tip: The best way to test for leaks is to use a water pressure gauge. Attach the gauge to a faucet and turn it on. If the reading is below 40 psi, there may be a leak.

9. Connecting dissimilar metals

When connecting two pieces of metal piping, it’s important to make sure they’re the same type of metal. Connecting dissimilar metals can create a chemical reaction that corrodes the pipes.

Tip: The best way to avoid this problem is to use dielectric unions to connect dissimilar metals. These unions have a rubber sleeve that prevents the two metals from coming into direct contact with each other.

10. Forgetting how to assemble parts you took apart

In the heat of the moment, it can be easy to forget how a particular fitting goes back together. To avoid this problem, it’s helpful to take pictures or make diagrams of the disassembled parts before you begin work. That way you’ll have a reference to consult if you get stuck.

Tip: Another helpful tip is to label the parts as you take them apart. This will make it easier to put everything back together in the correct order.

11. Not knowing where the main water shutoff valve is located

In the event of a major leak, it’s important to know where the main water shutoff valve is located so you can turn it off quickly. Otherwise, you risk flooding your home.

Tip: The main water shutoff valve is usually located near the water meter or where the main water line enters the house.

11. Trying to save money by using the wrong materials

In some cases, using cheaper materials can actually end up costing you more in the long run. For example, using PVC pipes instead of metal for a gas line can create a serious fire hazard. Make sure you use the right materials for the job, even if it means spending a little extra upfront.

Tip: Not sure what materials you need? Consult a professional before beginning any major plumbing project.

Leave a Comment