What You Need to Know Before Starting

A showerhead arm — the pipe that extends from the wall and holds your showerhead — can be replaced without calling a plumber, even if you have never done plumbing work before. The job takes 30 to 45 minutes and requires only basic tools you likely already own. The arm is threaded into a fitting inside the wall, so you unscrew the old one and screw in a new one, then reattach your showerhead.

The main challenge is not the replacement itself but reaching the fitting comfortably and keeping water from leaking at the connection point inside the wall. Both are manageable once you know what to expect. You will need to turn off the water supply to your shower before you start, though you do not need to drain the entire house.

Key Takeaways

  • Turn off the water at the shower valve or main shutoff before removing anything, and test that water stops flowing.
  • The showerhead arm screws into a fitting inside the wall, so you will need two adjustable wrenches — one to hold the fitting steady and one to turn the arm itself.
  • Wrap the threads of the new arm with plumber's tape (also called PTFE tape) before screwing it in to prevent leaks at the wall connection.
  • The arm must point slightly upward and be perfectly level side to side, or water will pool inside the pipe and drip when the shower is off.
  • If the fitting inside the wall spins when you try to unscrew the arm, you may need a specialized tool called a drop-ear elbow wrench, or you can call a plumber for that step.

Gather Your Tools and Materials

You will need two adjustable wrenches (sometimes called crescent wrenches) — one to hold the fitting steady inside the wall and one to turn the arm itself. If you do not have two, a pipe wrench works as the second tool. You also need plumber's tape, which is a thin white tape that wraps around threads to create a watertight seal. It costs a few dollars at any hardware store and comes in a small roll.

For the new arm itself, buy a shower arm or shower ell made of brass or galvanized steel, typically 6 to 8 inches long. Measure your old arm to match the length, or bring it to the store. You will also need a bucket or towel to catch water that drips from the old arm when you remove it — there will be some, even with the water off.

Optional but helpful: a drop cloth to protect your tub or floor, and a headlamp or flashlight if the space is dim. If the fitting inside the wall spins when you try to loosen the arm, you may need a drop-ear elbow wrench, a specialized tool that costs $15 to $25. Many hardware stores rent them for a few dollars if you do not want to buy one.

Turn Off the Water and Remove the Old Arm

Locate the shutoff valve for your shower. It is usually in the wall behind the showerhead, accessible through a small door or panel, or it may be under the sink or in a basement if your home is older. Turn the valve clockwise until it stops — do not force it. Then turn on the shower to confirm the water has stopped. If water still flows, find the main water shutoff for your house and turn that off instead.

Unscrew your showerhead by hand and set it aside. Use one wrench to hold the fitting inside the wall steady — you will grip it through the hole where the arm was. Use the second wrench to turn the old arm counterclockwise. Turn slowly and steadily. If the arm does not budge after 10 seconds of firm pressure, stop and spray the connection with penetrating oil (like WD-40), wait 15 minutes, and try again. Forcing a stuck arm can break the fitting inside the wall, which is much harder to fix.

Once the arm is loose, unscrew it by hand the rest of the way. Water will drip — this is normal. Let it drain into your bucket or towel. Inspect the fitting inside the wall. It should be a brass or steel fitting with threads. If it looks corroded or damaged, you may want to have a plumber assess it before installing the new arm.

Wrap the New Arm with Plumber's Tape

Take your new shower arm and look at the threaded end — the end that screws into the wall. Wrap plumber's tape around these threads clockwise, starting near the base and working toward the tip. Wrap it tightly enough that it does not slip, but you do not need to stretch it hard. Three to four layers is typical. The tape prevents water from leaking out around the threads where the arm meets the fitting inside the wall.

Plumber's tape is straightforward to use once you do it once. Tear it off the roll with your thumb, overlap each wrap slightly, and smooth it down as you go. If you wrap it counterclockwise by mistake, it will unwind as you screw the arm in — so pay attention to the direction. The tape is cheap, so if you mess up, unwrap it and start over.

Install the New Arm and Check the Angle

Screw the new arm into the fitting by hand first, turning clockwise. Once it is snug by hand, use your two wrenches to tighten it further. Hold the fitting steady with one wrench and turn the arm with the other, working slowly and steadily. Tighten until the arm is firm and does not wiggle, but do not over-tighten — you can crack the fitting or strip the threads.

As you tighten, position the arm so it points slightly upward (about 5 to 10 degrees above horizontal) and is perfectly level side to side. This angle lets water drain back toward the wall instead of pooling inside the pipe. Use a small level to check this if you have one, or eyeball it carefully. Once the arm is tight and at the correct angle, stop turning.

Reattach your showerhead by screwing it onto the end of the arm by hand. Turn on the water at the shutoff valve. Let the shower run for 30 seconds and watch the connection where the arm meets the wall. If water drips or sprays from that joint, turn off the water, remove the showerhead, and tighten the arm another quarter turn. Repeat until the connection is dry.

Test for Leaks and Troubleshoot

Run the shower for a full minute and watch the wall connection. The arm itself should not drip. If it does, the most common cause is that the plumber's tape was wrapped the wrong direction or did not cover all the threads. Turn off the water, remove the showerhead, unscrew the arm, and rewrap the tape, making sure to wrap clockwise.

If water drips from inside the wall (you will see it seeping out around the arm where it enters the wall), the fitting itself may be damaged or the old tape inside was not fully removed. This is less common and may require a plumber to access the fitting from inside the wall.

After the shower runs without leaking, turn it off and watch for drips from the showerhead itself over the next hour. A small drip or two is normal for the first few hours as air pockets clear. If water streams out, the shutoff valve may not be sealing properly, which is a separate issue unrelated to the arm replacement.

Common Mistakes to Avoid

The most frequent error is wrapping plumber's tape counterclockwise, which causes it to unwind as you screw the arm in. Always wrap clockwise. The second mistake is over-tightening the arm, which can crack the fitting or strip the threads. Tight enough to stop wiggling is tight enough — you do not need to use all your strength.

A third mistake is installing the arm level or pointing downward. Water will pool inside the pipe and drip from your showerhead when the shower is off. The arm must point slightly upward. Finally, do not forget to wrap the threads with plumber's tape. Without it, the connection will leak even if the arm is tight.

If the fitting inside the wall spins when you try to hold it with a wrench, stop when ready. Continuing to turn will damage the fitting. Instead, use a drop-ear elbow wrench if you have one, or call a plumber. Trying to force a spinning fitting is the one mistake that creates a bigger repair.

Frequently Asked Questions

What if water leaks from the showerhead after I turn off the shower?

A small drip for the first few hours is normal as air clears from the line. If it streams steadily, the shutoff valve is not sealing — this is not related to the arm replacement. If it only drips from the connection where the arm meets the wall, the plumber's tape was not applied correctly or the arm needs to be tightened another quarter turn.

Can I use the shower right away after replacing the arm?

Yes, once you have tested it and confirmed there are no leaks at the wall connection, the shower is ready to use. The plumber's tape sets when ready — there is no curing time.

What if the old arm will not unscrew?

Spray the connection with penetrating oil and wait 15 minutes. If it still will not budge, wait another 15 minutes and try again. Do not force it — you can break the fitting inside the wall. If it remains stuck after two applications of oil, a plumber can remove it safely using specialized tools.

Do I need to use plumber's tape if I use plumber's putty instead?

No. Plumber's putty and plumber's tape do the same job — seal the threads. Tape is easier to use and cleaner. Putty is messier but works just as well. Use one or the other, not both.

How do I know what size arm to buy?

Measure the length of your old arm from the wall to the end, or bring the old arm to the store and match it. Standard lengths are 6, 8, and 10 inches. The diameter is almost always 1/2 inch for residential showers. If you are unsure, ask a hardware store employee to confirm the size of your old arm.