It’s easy to fix most plumbing issues at home or updating existing fixtures with some few tools and little effort. Some of the work is not really challenging.

However, you would have to be more informed about the different types of fittings, pipes, solder, and glue since this is an area where most DIY enthusiasts fail.

plumber giving advice on common diy plumbing mistakes

Besides making mistakes related to using the wrong parts, there are a number of common mistakes that DIY enthusiasts make. Here are the top plumbing mistakes that you should avoid and do the work right.


Over Tightening Plumbing Connections

Over tightening plumbing fixtures such as toilet bolts, pipe fittings and supply tubes is the most common plumbing mistake. Excessive cranking on black or galvanized pipes, elbows, tees or coupling may crack the fitting.

Although cracking may not occur right away, excessive force may break the fixture some days or weeks later and this may lead to flooding.

Over tightening any plastic fittings in your toilet and supply tubes connecting faucets is also common. It only takes little pressure to seal supply tubes. However, tightening the nuts excessively may break them and cause some leakage.

Over tightening your toilet’s closet bolts or the tank and bowl components may its crack porcelain and damage your toilet, and you may need a plumber emergency service.

plumber over tightening plumbing connections


Using Inappropriate Tape or Wrapping a Thread Tape Backwards

Teflon tape, also known as PTFE tape, must be wrapped clockwise around threads to work as it is supposed to.

However, most DIY homeowners wrap it backwards such that the tape will unwind itself while tightening a fixture. This makes using the tape useless since it’ll not seal the fitting properly.

Tip for taping properly: Wrap the tape around the fixture’s threads for three times. The final wrap should face left while screwing the fixture into place. In case the last wrap faces your right-hand side, you should stop screwing and wrap the fixture again.

You should only use the appropriate tape:

  • Use a gas-rated yellow tape for threading gas line fittings
  • Use thick pink or white tape for water supply fittings
  • Never use any thread tapes on flare or compression fixtures

Using Drain Line Cleaners as the First Option

The simplest way to unclog bathroom and kitchen sinks is using barbed drainage cleaning tools or a snake. Another option is removing the drain P-trap, followed by pouring out the material cause the blockage.

However, most DIY enthusiasts use liquid drain cleaners as the first choice and pour excessive amount into the drain.

plumber using drain line cleaners

This is a big mistake since liquid drain cleaners are not the best option. These cleaners often lead to more issues than what they actually solve because:

  • If a liquid cleaner fails to clear the drain clog, you may end up removing the drain trap arm in future and it will be full of the corrosive cleaner.
  • Using excessive amounts of the cleaner and using it more times than necessary may damage metallic pipes and traps. This may cause leakage.
  • Liquid cleaners destroy rubber gaskets in couplings. This may cause leakage in the future.


Handling Plumbing Jobs without the Necessary Spare Parts

Most DIY homeowners make the common mistake of purchasing a washer or cartridge for repairing the faucet. If the cartridge or washer are worn out, then other parts of the faucet might also be worn out.

If you fail to replace O-rings, gasket, and stem when replacing a cartridge or washer, then you may end up having a leaking faucet.

This will mean going to the local hardware store again and disassembling and reassembling the faucet again. Such peripheral components are affordable, thus buy them upfront to rebuild your faucet at a go rather than going through the stress of replacing one part at a time.

Also, do the same when fixing drain lines. In case you have to disassemble any metallic arm or p-trap, ensure you have sufficient rubber gaskets so as to replace any disassembled gaskets. You may reuse bevelled washers in PVC arms and traps.

However, ensure you have some spares just in case you’ll come across a damaged or lose washer or while working on the plumbing fixture.


Failing to Turn Off Water

Most people assume that they’ll leave water supplies on and go ahead to change a valve quickly. Doing it this way is hardly successful.

If you’ll be unable to fix a new faucet or valve quickly, water may end up flooding your home and even flow to the adjacent rooms and lower floors.

Thus, avoid risking your money for something you can take time to do carefully by first turning off any all water supplies leading to the fixture. Experienced plumbers start with turning off the main valve. You should do the same before doing such repairs.


Using Excessive Force on Valves Stuck on Shut Off

Toilet and sink valves usually fail to turn especially when not used for many days. In case you’re unable to turn open the valve using your hand, the problem will not be solved by using more force.

You may break the knob and even damage the stem of the valve. This problem is usually as a result of the packing seal welding itself onto the stem, thereby making it fail to turn.

The best solution is using a wrench to try and loosen the nut that holds the stem in place. This will break the tight bond and the knob will turn easily. Once done, snug the nut to ensure there’s no leakage.


Sweating a Copper Pipe with Water

Copper fittings and pipes must be dry before any attempt to sweat them. In case there’s water near the area you are working on, it will make the joint leak.

Trying to heat the water using a torch with the aim of making it evaporate while soldering never works. Steam will only create pin holes as you solder.

You’ll end up noticing water jets shooting from the soldered point and you’ll be forced to start the repair all over again.

The ideal solution is plugging the pipe you’re working on with some white bread. This is a plug that looks like a capsule. Do this before working with the torch and become an expert in soldering plumbing fixtures.


Lacking the Appropriate Tools

Most plumbers make plumbing look easy since they have all the appropriate tools. DIY lovers often use inappropriate tools and this is where everything starts going wrong.

For instance, any attempt to remove old galvanized nipples with typical pliers or pipe wrench may break the water pipe whereas the threads will be left on the wall. Avoid such damages by investing in the right tools.

plumbing tools

You can easily find an affordable set of pipe wrenches in your local hardware store. Do the same for all plumbing repairs and installations.

  • Be careful not to damage the faucet finishing when using strap wrenches. Wrapping the contact jaws of a wrench using electrician’s tape can be a good option.
  • Remove extremely stubborn faucet fasteners and supply tubes using an adjustable basin wrench.
  • Speed up any copper burnishing using a combination of exterior and interior wire brush.
  • Avoid using hacksaws to cut squares. Instead, use an appropriate tubing cutter to cut perfect squares on any tubing.


Mixing up Elbows, Tees and Wyes

It’s very important to know the right fitting for each application. This way, you’ll avoid violating plumbing codes and getting foul smells in your home.

For instance, installing a wye for connecting the drain p-trap and adding a 45 degrees elbow for horizontal connections may look as if it’s done right.

However, this is a violation of plumbing codes and may lead to major problems. Drainage water will obviously flow faster down the slope and may siphon some water from the drain p-trap. This would allow sewer gases into the home.

In this case, the best option would be using the right sanitary tee. However, tees are not used in all drainage applications.

For instance, you cannot use a tee when you want to connect a horizontal pipe to another horizontal pipe or connecting vertical pipes to horizontal drains.

Thus, different applications may require a wye, tee, or short/long elbow. Also, a 90 degrees elbow cannot be used to alter the direction of your drain unless you can stand frequent unclogging. Thus, you should know which fitting to use for which application.

Tutorials on plumbing may assist you in finding out the right applications for different fittings. You can also ask your local area plumbing inspector for more information before buying any fittings.


Installing Saddle Valves in Humidifiers or Ice Makers

Saddle valves do not meet today’s plumbing codes. However, some furnace humidifiers and ice makers come with saddle valves.

You can also purchase them at some local stores. Thus, some people still use them in DIY repairs. However, this is a huge mistake. These valves tend to cause leaks in case they undergo shutting and opening cycles too often.

Since they are installed in hidden areas, leaks are not easily noticeable and they may lead to mould problems. Instead, use ball valves in such fittings.

If your fittings came with saddle valves, replace them with ball valves before the saddle valves cause leakage.


Inadequate Slope

Excessively high slopes are not ideal in plumbing. If you assume that higher slopes will make everything easier, then you’re wrong.

Higher slopes will make liquids move faster and solids slower. Thus, solids will be left behind and this will lead to problems. The best slope should be ¼ ‘’ for every foot.


Inadequate Cleanouts

At times, cleanouts are not set in the right locations. There should be adequate clearance to fix a clogged drain line. Cleanouts are not supposed to be fitted beyond your property’s first floor.

However, you may consider installing them. This will depend on whether the drain line design allows for adding cleanouts to assist in servicing the drain.

Each and every sanitary stack should have a cleanout in instances where horizontal branches are 100ft apart. They’re also necessary where the line changes direction beyond 45 degrees. You should also use them within a connection of 10ft between the drain and sewer.


Spacing around Toilets

Ensure there’s enough space for moving around your toilet. The minimum recommended distance between the toilet and the side wall is 15 inches. Also, the minimum recommended distance between the toilet and the front wall is 18 inches.

spacing around bathroom toilet


Ignoring Local Codes

A plumber needs to follow the local plumbing codes of a given location. For example, a licensed and professional Sydney plumber must know all the local codes for plumbing in the NSW region. However, average homeowners may not know much about the regulations.

Thus, it’s recommended to check with local authority officials before doing any project on your own. Handling any plumbing project without knowing the regulations involved may put you in trouble with the authorities. The extent of work will determine whether you need to get a permit.

This will also depend on the state or city. For instance, some areas require permits for installing toilets while others only require permits when doing large scale remodels and renovations. Thus, before doing any DIY project that involves plumbing, learn more about the plumbing codes in your local area.

Wondering why you need to follow local regulations? Well, local authorities may not come to your home to check your bathroom or plumbing. However, doing plumbing work without permits may lead to several problems.

After all, unlicensed DIY work is amateur work. Going through video tutorials and written material may not offer you enough knowledge and experience.

Although a handy DIY person may complete small plumbing jobs successfully, larger projects require professionals to handle all details correctly and in accordance with the set codes.

In case a DIY repair or installation leaks or fails, you’ll surely have to contact a plumber to handle the damage. In case there’s extensive leakage that damages your property, then you may experience problems with your insurance.

Insurers often refuse to pay for claims involving damages that are as a result of projects done without permits. You will also incur the cost of paying fines if caught working without permits where needed. The amount you’ll pay will depend on the extent of violations and your area.


Pouring Grease and Oils down Your Drain

Most people make the mistake of pouring grease into the drain. In case you’re left with grease after preparing a meal, you might be tempted to pour it into the sink or drain. However, this is never recommended.

Grease is a major cause of a clogged drain. Rinsing the sink or drain with boiling water may not clear the entire drain. After some time, it will solidify and clog your drainage.


Flushing Any Material Down Your Toilet

Most people flush improper materials down their toilets despite knowing it’s not a good idea. Although the toilet piping looks large enough, it leads into a smaller pipe that measures 3 inches in most standards.

This is the piping that the entire home drains into. Thus, flushing larger materials than the size of the pipe may clog your entire drain.

Every homeowner should always remember that pipes are specially designed to assist with plumbing and not any other application.

Also, it helps to know what makes causes clogging and what damages the pipes. Although you’ll still need the services of a plumber in the event of a damage or renovation, it’ll help to do the right thing by avoiding plumbing mistakes.


Related: Tips on Choosing a Professional Qualified Plumber