If you have a shower leaking from the shower arm, you might need just a simple fix or a somewhat major repair, depending on where the leak is and your plumbing setup. To confirm the terminology, a shower arm is the short length of pipe that comes out of the wall and connects to the showerhead. Shower arms typically have a slight bend near their middle, and they almost always have threads on both ends. One end threads into a fitting called a drop-ear elbow inside the wall; the other end receives the showerhead, which simply turns onto the exposed end of the arm. The first step in dealing with a shower leaking from a shower arm is to determine exactly where the leak is coming from.
Where Shower Arms Can Leak
A shower arm can break in the wall or cause the vertical pipe in the wall to break if too much pressure is applied while unscrewing the showerhead or shower arm. Damaging the shower arm while the showerhead is being replaced is a surprisingly common occurrence. The shower arm may also get damaged simply by the repeated pressure of adjusting the showerhead over years of use. Sometimes it is the threaded end attached to the showerhead that gets damaged, but more problematic is when pressure on the shower arm causes damage to the connection inside the wall. It's also possible that either of the threaded joints simply isn't sealing properly.
Leaking at the Showerhead
If your shower leaking seems to be coming from the base of the showerhead, look for a crack in the showerhead and the shower arm. Many showerheads look like metal but are actually plastic with a chrome finish. And plastic cracks a lot more easily than metal (but metal can crack, too). If there are no visible cracks, try the following fixes:
- Unscrew the showerhead. If necessary, hold the shower arm with pliers to keep it from turning. Tip: Wrap the pliers' jaws with masking tape to prevent scratching the shower arm.
- Clean the threads of the shower arm, removing any old plumber's tape, pipe-joint compound, and mineral deposits.
- Wrap plumber's tape around the threads of the shower arm, wrapping in the same direction that the showerhead will twist back on.
- Reinstall the showerhead, tightening it until it is very snug. You shouldn't need to tighten the showerhead with pliers, but if tightening is difficult, hold the shower arm with one pair of pliers and tighten the showerhead with another pair.
- Test the connection for leaks. If it still leaks, tighten the showerhead a bit more. If that doesn't stop the leak, replace the shower arm (see below).
Leaking Inside the Wall
Now it's time to consider that drop-ear elbow. Just like the showerhead, the threaded connection between the shower arm and the elbow can leak. The remedy for this is similar to the showerhead fix: remove the shower arm, clean the threads, and reinstall the arm (or replace it if it's cracked or corroded) with a new application of plumber's tape. The arm simply twists into the elbow like a bolt into a nut. Just be careful not to cross-thread the connection when you start turning. Also be careful not to tighten the arm too much and risk damaging the elbow or the pipe.
Leaking Beyond the Shower Arm
If reinstalling or replacing the arm doesn't stop your shower leaking, you may have a problem with the drop-ear elbow or with the vertical shower pipe. There are several different ways to fix this, but all require gaining access to the shower plumbing. If someone installed an access panel on the other side of the shower wall, you're in luck; if not, you'll probably have to cut a hole in the backside of the wall to access the plumbing (hopefully it's just drywall, which is relatively easy to patch).
Once the plumbing is visible, you can see where the leaking occurs and what type of piping you have. If it's galvanized pipe, the drop-ear elbow is probably threaded onto the end of the vertical pipe and you can simply twist off the old one and twist on a new one (with plumber's tape, of course). If the piping is copper, all of the joints are probably soldered. This means you'll have a decision to make. Soldered copper is still the gold standard of plumbing connections; if you want the same quality, hire a plumber for the repair. He or she might be able to cut the vertical pipe and add a new section, along with a new drop-ear elbow, using a soldered coupling. Or, you might decide that it's a good time to replace the entire shower faucet.
Alternatively, you can splice in a new section of shower pipe or even replace the faucet yourself. But if you're not an expert at soldering, you'll have to use something like PEXor use push-in fittings (SharkBite is one popular brand). There's nothing wrong with these options, provided you install them properly. The easiest repair for a leaky shower pipe or drop-ear elbow is to cut the shower pipe above the faucet and splice in a new length of pipe using a push-in coupling, then install a push-in drop-ear elbow to the top end of the pipe. Secure the elbow the wall framing and install a new shower arm to complete the repair.