How to fix a leaking pipe joint: PVC, PEX, copper and steel

Pipe joints are the most common cause of water leaks as it is a weaker point. The leak may be at the joint or a crack in the pipe may allow water to seep through. Often you have to replace a piece of pipe. How this is done depends on the type of material of your pipe (see below).

If you have a leaking pipe joint, it is important that you get it fixed as soon as possible. Here are some tips on how to fix a leaking pipe joint without having to do any major repairs. SharkBites have made a repair without tools a lot easier. Plumbers generally don’t like these but they are quite easy to work with.


Do you have a leak?

Checking if you have a leak in your house is quite easy. Turn off every faucet and device that uses water. Check the water meter (often found outside or in the garage). Write down the numbers that you see and wait 15 minutes. Then you check the numbers on the water meter again. If they haven’t changed significantly, you probably don’t have a leak or a small one. To further isolate the cause, you can do the same test with some of the water circuits closed. For example, you can close the cold water line and see if it has a leak there or not. 

You can also check the evolution of your water bill to check if you have a leak. 

What causes a pipe joint to leak?

Leaks happen when the pressure in one pipe increases, while the other pipe is being drained. The result is that water flows around this joint, causing it to leak. This happens most often with cast iron pipes (these pipes are grey). Copper has a red/brown color and can also leak if it has been improperly soldered. PEX can leak as well but this will mainly happen around the collector.

Gas pipes can leak as well and these can give a special smell as this has been added to the gas to make it easier to find. You can find the location by applying soap water to the pipe. If you see bubbles, this can indicate a leak. It is best to call your plumber as fixing natural gas lines by yourself is not a good idea as it can lead to troubles down the road. This is why we won’t discuss this further. 

How do I fix or seal a leaking pipe joint? PVC, PEX, copper and steel

The first step is to find the source of the leak. You can do this by checking your faucet or spigot and looking for any signs of water damage.

Photo by Abigail Lynn on Unsplash

Copper can turn black when it leaks. There are also water meters and listening devices that can help you find leaks under the floor. This can be quite a challenge though. Luckily plumbers have special equipment to fid water leaks.

The next step is to check to see if there was a crack in the pipe that caused a leak. If so, you can start cleaning up the area.

-If it is in a water supply pipe:

 Once this is done, you can turn off the water supply. This is done by turning a valve. Once this is done, you can open a faucet to drain the water. If it is a leak in your radiator system, you should find a valve to remove the water. This can be a lot of water so be prepared to turn the valve off. Grab a bucket and some towels before you do this. If the leak is behind the wall or under the floor, you have to open this up. Most people should let a professional do this as it can affect the stability of the house. 

It is also important that you get the right new joint as this comes in a lot of shapes and diameters. 

-For steel: see if the fitting is cracked or not. In some instances, a small nudge/image on a bolt can close the pipe again. If the fitting needs to be replaced, you will have to take it off and see if you can replace it. Make sure to use a sealant such as Teflon tape around the pipe. The new joint can often just be screwed on the existing pipe. Don’t overtighten it though! You are just turning the fitting around to get it off and do the same to get a new one on the pipes. Be sure to test your work and check if it leaks. Steel pipes can be quite old and once they start leaking, it might be a great idea to start thinking about replacing them. 

If the hole is quite far away from the fitting, adding a clamp can work. This is discussed in the video below. Check your local code to see if this is allowed in your area.

For copper:  the easiest way is to cut away a piece of pipe with a pipe cutter. Then you measure how long the new piece has to be. Be sure to take the new fitting into account. SharkBites are fittings that are easy to install without tools. Clean the pipe after you have cut it to remove debris inside. Once this is done, you just have to push two pieces together and you are done. There are more temporary solutions as well, as can be seen below. Some are not following the code though.

For PEX: Check the manifold as this piece often leaks. Often the whole PEX line is replaced by connecting the old one with a new pipe. The old pipe is then used to pull the new one in. It is often best to leave this to a plumber as it can be a mess if the pipe breaks while you are doing this. You can use a PEX tubing cutter to remove the piece with the leak. Be sure to recalibrate the pipe so that it is round again. Then you can use Sharkbites to connect a new piece of pipe with the old one if you have PEX-B. Just slide the pieces together. For PEX-A, you have to use other systems such as the one made by Uponor.

If it is in a waste pipe:

-For PVC you will need a saw and glue. Remove the piece that is leaking before the joint. Leave some space so that it is easy to install the new joint. Gluing PVC is quite easy but you have to follow all the steps. You can also unglue a joint by heating it up. The PVC will probably get damaged though. Most people should just call a plumber as a leak in the water pipe can create an enormous mess.

In some instances, you can replace the PVC with PP that has a rubber ring inside. This is easier to work with as you just have to slide pieces together. You don’t have to mess with glue or primers. 

If the leak is more serious, like a pipe bursting, then it would be necessary to have a professional help you out. A plumber can come in and repair any damages that have been done. If this is not an option for you, then make sure to contact your local utility company. They will also be able to help you fix your leaking pipe joint as soon as possible.

How to prevent future leaks 

After the initial repair, check your pipes for any additional leaks. Joints are weak points and often have to be replaced. If you find any other leaks, fix them immediately.

Try to determine the root cause of the leak. For example, copper pipes need a lot of support. If they don’t hang straight, they can start to leak. It is also possible that copper and metal pipes interact and start to break.

Standing water can also affect a pipe. Another common cause of broken joints is that the pipes have been used a lot and it is time to replace them.

Photo by Daniel Fazio on Unsplash

Earthquakes can also affect your pipes. 

In some instances, you might need to hire an engineering firm that examines your pipes to see what is going on. For example, a broken water tank can send metal particles into your copper pipes. After a while, these pieces can create leaks in your pipes.

Chalk can also be built up in pipes and make them weaker. Check with your neighbors if they have problems as well as there might be an issue with the city water as well. There are a lot of causes of leaks so see what the main problem is. Sometimes the plumbers make mistakes and this can lead to leaks as well. For example, sometimes copper pipes are not properly deburred and this can lead to problems at the joints as there is sediment in the pipes. 


To fix a leaking pipe joint, you have to check the type of material and go from there. SharkBites have made it a lot easier to work on pipes and replace joints. You can also ask a plumber to check your installation. If one joint leaks, it can indicate that there are more problems are coming.

If you have no water coming out of a faucet or spigot, you can check the joints to see if there is a leak.