How to Diagnose a Leaking Shower
You have a leaking shower but how do you figure out what is causing the leak? Is it the shower pan, or the enclosure? Or maybe the plumbing?
Below is a check list to determine what is causing the leak. You will be testing the shower pan and drain flange, drain pipe and trap, hot/cold plumbing, and shower enclosure. Identifying the problem area will help you in deciding what trade to call first.
1. Plug the drain pipe. Do this by removing the strainer cap and inserting a test plug down into the pipe. There are a couple options for test plugs. The simplest and cheapest way is to use a wing-nut expansion plug for you diameter drain (1.5” or 2”). These sell for a few dollars at the local hardware store. However, you may find that your drain design makes it difficult to use this type of plug. In those cases, the most versatile type is the pneumatic plug often referred to as a Ball Plug or Weenie Plug that you pump with air (read more about plugs at our Test Plugs article). These are more expensive, usually around $30 for a 2” diameter plug with a 6” long chain. If you are a contractor or a professional handyman you should add this reusable tool to your tool box.
2. Expose the area where the leak is showing and dry it out. This might mean cutting out some of the wall or ceiling to get a better view of the leak source.
3. Fill the shower pan with no more than one (1) inch of water. You need to use water from a source outside the shower. This probably means filling a bucket with water from the garden hose and pouring it into the shower. Go to the area where the leak is showing and check to see if there is water coming out. If not, wait a few hours and check back again. If after 24 hours there is still no sign of water leaking then you can rule out the shower pan and drain flange.
4. Now you will test the drain pipe and trap. Pull the plug and let the water go and also pour in another bucket of water. If you see water in the leak area you know it is the pipe or trap.
5. Now you will test the glass walls or shower enclosure. You NEED to use a source of water from outside the shower like a garden hose or pump sprayer. Direct a pressurized water stream at the different areas of the shower enclosure. If water leaks you know it has something to do with the shower enclosure if not then your final test will be the Hot/Cold plumbing.
6. Now you will test your Hot/Cold and shower head plumbing. Run your shower making sure to to get as little water on the shower enclosure. If water leaks then it is most likely the source plumbing.
The purpose of all these steps is to isolate the potential problem area. It is possible that several areas can be causing the leak so you may want to test them all. But at the least do steps 1-3 to figure out whether to call a shower pan contractor or a plumber.