How To Extend A Bathtub Spout Pipe – 2 Methods To Try

Is your bathtub spout pipe falling short? Don't worry, there are two distinct methods to extend it effectively.

The first way is to solder a coupling and piece of extension pipe onto the spout pipe. The second method uses a pipe-fit plumbing fitting instead of a coupler and soldering torch.

They both have their advantages and disadvantages and their own set of steps for the process. 

Soldering method:

  1. Gather tools and materials
  2. Prepare the extension pipe
  3. Solder the pipes together

Pipe-fit method:

  1. Gather materials
  2. Cut the pipe
  3. Attach the extension pipe

It can be very frustrating to find out that the pipe behind your bathtub faucet is too short. This can lead to leaking, which can lead to countless other problems.

That's why it's good to diagnose and fix the problem as soon as you notice it. Both of the methods outlined above will get the job done.

However, one of them may be better depending on your individual situation. Make sure you keep reading below to learn both methods in detail so you can pick the best one for your needs.

Soldering Method

The soldering method will give you the best long-term solution for extending your bathtub spout pipe. You'll need a small propane torch with a regulator tip for this method.

Since you are soldering the pipes together, they cannot be undone easily. This is great if you never need to work on this pipe again, but it can be frustrating if you do have to in the foreseeable future.

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Using a soldering tool can also be understandably intimidating if you haven't before or aren't completely comfortable using it in your home.

So it's best to first learn how to use one safely or hire someone to do the job. 

1. Gathering Tools and Materials

First, you'll need the coupling piece and piece of pipe for the extension. You will also need a small propane torch with a regulator that has a built-in igniter.

A striking tool would also be necessary if it does not have a built-in igniter. Next, you will need flux to prepare the copper pipes for soldering together and a pipe cutter.


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The last materials you need for this job are an emery cloth, lead-free solder, and, of course protective equipment. Safety is always the top priority.

2. Prepare the Extension Pipe

To get the pipes ready to be soldered, you first have to cut the extension pipe. When measuring, be mindful of the length of the coupling piece as well since that will add to the overall length.

For this job, you can use a tube cutter or just a handsaw. If you use a handsaw, you'll have to make sure that you file and smooth the edges of the pipe since they will be a bit rough. 

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After the pipe is cut, you'll want to use the emery cloth and flux. Use the emery cloth on the ends of the extension pipe as well as the bathtub spout pipe.

Make sure to do the inside of the pipe as well. You'll know that you've used the emery cloth enough when the copper pipe shines.

Next, using a brush, cover all of the ends that are being joined in an even layer of the flux. Lastly, push the extension pipe into the coupler and then the coupler onto the wall pipe. 

3. Solder the Pipes Together

Since this part can be very dangerous, make sure to either hire a professional or thoroughly research everything necessary to do the job safely.

Make sure that you have all of the necessary protective gear on before starting. After that, the first step is to carefully light the propane torch. 

Place the soldering where the extension piece and coupler meet. Then, slowly use the propane torch to melt the soldering onto the joint while going around the entire circumference of the pipe.

Next, repeat that process where the coupler meets the bathtub spout pipe. Make sure to wait at least a minute for the soldering to cool in between the second section and after the job is done. 

Here is a great visual guide for learning how to solder copper pipes together:

Pipe-fit Method

This method requires a lot less than soldering does. It takes fewer materials, less time, and less knowledge.

This is why it is a very useful method to know for more casual do-it-yourself homeowners. It's also generally much safer to perform since no torch is involved.

Using a pipe-fit is also fairly easy to take apart if necessary. This, unfortunately, means that it's not permanent and not anywhere near as secure as the soldering method. 

1. Gather Materials

All you really need for this method is the pipe-fit, the pipe extension, and a way to cut and smooth out the pipes.

This is much simpler than the long list of supplies needed for the other method. However, this method is not as secure, so you have to install it as properly as possible to prevent leaks.  

2. Cut the Pipe

Now, it's time to cut the extension pipe. Remember that the length of the pipe-fit will play into the overall length while measuring the extension pipe.

You can use a tube cutter or a hand saw again in this method. Just make sure that if there are any rough edges on the pipes, they're filed and smoothed before attempting any attachments. 

3. Attach the Extension Pipe

When it comes time to attach the pipes, all you need is some elbow grease. If you are using the pipe-fit shown above, then the pipes will fit into it.

Other pipe-fits go inside of the pipes, so be aware of which kind you have. First, push the extension pipe into the end of the pipe-fit and make sure it is secure and locked in.

Then, push the other end of the pipe-fit onto the bathtub spout pipe. Again, make sure it is secured and locked. 

Not sure about doing any DIY jobs? Learn the specifics of having your local plumber do the installation for you.

More Bathtub Spout Pipe Extension Questions

Now that you know how to get the job done with two different methods, fixing your plumbing issue should be much easier.

However, it's good to have all of your questions answered before picking a method and starting the job. 

How Long Should the Tub Spout Be?

The standard length for a tub spout is 5-1/4th or 5-1/2 inches.

Whether it is a slip-on tub spout or a threaded tub spout can also play a factor. For slip-on spouts, it should be at least 1 inch and no more than 2-7/8 inches.

After that, it depends on the faucet you attach to the pipe. Make sure that if your pipe is in that range for the length, you buy a faucet with corresponding measurements. 

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Are you curious about the optimal height for your bathtub faucet installation? Discover the key details by reading this article.

Do Tub Spouts Come in Different Sizes?

There is no one-size-fits-all when it comes to tub spouts. They vary in size, and the plumbing installation can differ in depth. But typically, you'll find them from 5-1/2 inches to over 9 inches.

If you need a specific type of spout, some adapters can help if you have a slip-on or screw pipe and the opposite kind of faucet. These will add a little length to it overall as well. 

Can PEX Be Used for Tub Spout?

PEX pipe should not be used in this situation. While it may be good for the temperature of the water, it cannot do the rest of the job.

PEX is not strong or sturdy enough to hold up the bathtub faucet. 

How Do You Fill Gap Between Tub Spout and Wall?

White fitted bathtub inside a modern bathroom

After you install your new tub faucet, you may notice a small gap between it and the wall. This is to be expected. The most appropriate way to handle this is with caulk.

Using caulk has a dual purpose in this situation. It will fill the gap that you're worried about.

More importantly, it will also stop any water from getting inside the wall. This is very important because of the endless amount of damage water in your walls can do. 

Do you have a slow-draining bathtub? Find effective solutions in this guide.

Finishing Up

Small white fitted bathtub inside a small bedroom

If you find yourself needing to extend the length of your bathtub spout pipe, then you can use two different methods.

Soldering the extension and coupler onto the existing pipe is the most secure and long-term solution. However, using a pipe-fit is a lot simpler and safer for newcomers to this project.

The pipe-fit method just isn't as secure. You will have to weigh the pros and cons of both methods to find one that works the best for you!

A repair man pulling a faucet pipe out of the bathroom wall, How To Extend A Bathtub Spout Pipe - 2 Methods To Try

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