How to Leak-test a Shower Pan

Shower pans are either single pieces of fiberglass that drop into the floor, or they consist of a mortar bed with tile. The purpose of the shower pan is to prevent water from flowing out into the bathroom. Over time, shower pans can develop leaks, which may occur around the base or near the drain. Any time that you install a new shower pan or observe water on the bathroom floor, you should test the pan.

Testing shower pans for leaks prevents future floor damage.

Step 1

Wipe the shower pan with a towel to remove all moisture on it, especially around the drain area.

Step 2

Tear off 5-inch strips of duct tape and place them over the drain in the bottom of the shower pan. Press the tape down tightly around the edges to create a watertight seal.

Step 3

Walk to another faucet in the home and fill a bucket with water. Dump the water slowly into the shower pan and continue until it has 1 inch of water in the bottom. Mark the top of the water line using a dry-erase marker.

Step 4

Monitor the water once per hour to see if it has dropped below the marker line. If so, look closely at the floors and walls surrounding the shower pan to see if they are damp. If no dampness exists, the leaks may be in the seal between the shower pan and the drain opening.

Step 5

Check the shower pan drain seal by dropping one to two drops of food coloring 1/2-inch away from the drain. Observe the dye to see if it flows immediately toward the drain, which indicates a leak.

Things You Will Need

  • Towel
  • Duct tape
  • Bucket
  • Water
  • Dry-erase marker
  • Food coloring


  • You can also purchase a compression plug from the hardware store and insert it into the drain to stop the flow of water.


  • Do not simply turn on the shower faucet to fill the pan with water, since leaks can occur at the faucet and you may be unable to determine the true source of the leak.

About the Author

Kimberly Johnson is a freelance writer whose articles have appeared in various online publications including eHow, Suite101 and Examiner. She has a degree in journalism from the University of Georgia and began writing professionally in 2001.

Photo Credits

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