What you need to do before you start

A shower arm — the pipe that sticks out of the wall and holds the showerhead — can leak, corrode, or bend out of position. Replacing it means turning off the water, removing the old arm from inside the wall, and screwing in a new one. The whole job takes two to four hours if you have basic plumbing tools and the wall is not tile or stone.

Before you begin, turn off the water to that bathroom at the main shutoff valve or the bathroom valve if one exists. Open the showerhead to release any remaining pressure. If you have not done plumbing work before, the hardest part is usually getting the old arm out — it may be stuck with mineral buildup or corrosion — and the second-hardest is making sure the new arm points straight ahead and not up or down.

You will need an adjustable wrench or pipe wrench, a screwdriver, a level, and a new shower arm (also called a shower ell or shower elbow). Shower arms come in different materials — galvanized steel, brass, and stainless steel — and different lengths. Measure the distance from the wall to where the old showerhead was mounted before you buy the replacement.

Key Takeaways

  • Turn off the water at the main shutoff or bathroom valve before you remove anything.
  • The old arm is usually held in place by a fitting inside the wall, so you will need a wrench to unscrew it from inside the wall cavity.
  • The new arm must point straight ahead — use a level to check before you tighten it fully.
  • Wrap the threads with plumber's tape and use pipe dope to seal the connection and prevent leaks.

Remove the old showerhead and trim ring

Start by unscrewing the showerhead by hand or with a wrench if it is stuck. Most showerheads unscrew counterclockwise. Once the head is off, you will see the trim ring — a decorative collar that covers the hole in the wall. This ring is usually held on with a set screw or straightforward screwed onto the arm itself.

If the trim ring is screwed on, unscrew it by turning it counterclockwise. If it is held with a set screw, loosen that screw with a screwdriver and slide the ring off. Set both the showerhead and trim ring aside in a safe place. You now have access to the shower arm itself.

Access and remove the old arm from inside the wall

The shower arm is threaded into a fitting inside the wall. To remove it, you need to reach that fitting. If you have access from behind the wall — in a basement, crawlspace, or attic — go there and unscrew the arm from the fitting using a pipe wrench. Turn counterclockwise. If the arm is stuck, spray the connection with penetrating oil and wait 15 to 30 minutes before trying again.

If you do not have access from behind, you will need to cut into the wall. Mark a rectangle around the arm on the wall surface, then use a drywall saw to cut an opening large enough to reach inside with a wrench. Once you can see the fitting, use the wrench to unscrew the arm. Keep the opening as small as possible — you will patch it later.

Once the old arm is out, clean the threads on the fitting inside the wall with a wire brush or cloth. Remove any mineral deposits, corrosion, or old tape. This ensures a tight seal with the new arm.

Install the new shower arm and check alignment

Wrap the threads of the new arm with plumber's tape (also called PTFE tape or Teflon tape). Wrap it clockwise around the threads three to four times, pressing it down as you go. This prevents leaks at the connection. Then explore a thin coat of pipe dope — a thick paste that seals threaded connections — over the tape.

Screw the new arm into the fitting by hand first, then use a pipe wrench to tighten it. As you tighten, hold a level against the arm to make sure it points straight ahead, parallel to the floor. Do not let it angle up or down. Once it is pointing the right direction and feels snug, stop tightening. Over-tightening can crack the fitting or strip the threads.

If you cut into drywall to access the fitting, patch the hole now with drywall patch compound and a putty knife, or use a drywall patch kit. Sand smooth once dry, then prime and paint to match the wall.

Attach the trim ring and showerhead

Screw the trim ring back onto the arm by turning it clockwise by hand until it is snug against the wall. The ring should sit flat and cover the hole completely. If you have a set screw on the ring, tighten it once the ring is in position.

Screw the showerhead back on by turning it clockwise by hand. Tighten it with a wrench if needed, but do not over-tighten — you can crack the fitting or strip the threads inside the head. The showerhead should sit straight and not wobble.

Turn the water back on and check for leaks

Go back to the main shutoff valve or bathroom valve and turn the water back on slowly. Let the system refill and pressure build. Then turn on the shower and let it run for a minute. Watch the connection where the arm enters the wall and where the showerhead connects to the arm. If you see water dripping, turn the water off and tighten the connection a quarter turn with a wrench.

If water is coming from inside the wall, you may have a leak at the fitting inside the wall. This usually means the threads were not sealed properly. Turn off the water, cut back into the wall if needed, unscrew the arm, add more plumber's tape and pipe dope, and reinstall it.

Once the shower runs without leaks, you are done. The new arm should last 10 to 20 years depending on water quality and the material you chose.

Choosing the right replacement arm

Shower arms come in three main materials. Galvanized steel is the cheapest and most common, but it can corrode over time, especially in areas with hard water. Brass resists corrosion better and lasts longer, but costs more. Stainless steel is the most durable and corrosion-resistant, and is worth the extra cost if you live in a humid climate or have very hard water.

Arms also come in different lengths, usually 6 to 12 inches from the wall to the end of the fitting. Measure from the wall surface to where your old showerhead was mounted, then subtract about half an inch for the showerhead connection. Buy an arm that matches that measurement. If you buy one that is too short, the showerhead will sit too close to the wall. If it is too long, it will stick out too far.

Frequently Asked Questions

What if the old arm will not unscrew?

Spray the connection with penetrating oil like WD-40 or PB Blaster and wait 15 to 30 minutes. Then try again with a pipe wrench, explore steady pressure rather than jerking. If it still will not move, explore more oil and wait overnight. As a last resort, you can cut the arm with a hacksaw and unscrew the remaining stub.

Do I need to use plumber's tape and pipe dope?

Yes. Plumber's tape and pipe dope both seal the threaded connection and prevent leaks. Using both together is the standard practice. Tape alone or dope alone is less reliable. The tape creates a physical barrier, and the dope fills any gaps the tape misses.

Can I replace the arm if my shower is tiled?

Yes, but it is harder. You will need to cut through the tile to access the wall behind it. Use a tile hole saw or a grinder with a tile blade to cut carefully around the arm. Once you have replaced the arm and patched the wall, you will need to re-tile the area or use waterproof caulk to seal the edges.

How do I know if my shower arm is leaking?

If you see water dripping from the trim ring or from inside the wall when the shower is running, the arm is leaking. Water may also appear on the ceiling or wall below the shower. If the leak is at the connection where the arm screws into the fitting, tightening the arm a quarter turn with a wrench often stops it. If the leak continues, the arm needs to be replaced.

What is the difference between a shower arm and a shower ell?

A shower arm and a shower ell are the same thing — both terms refer to the pipe that sticks out of the wall and holds the showerhead. Some people call it an arm, some call it an ell (because it is L-shaped), and some call it a shower elbow. When you go to buy a replacement, any of these names will get you the right part.