Run the tests in this order
Let the area below dry between tests so each result is clear.
- Test 1: nothing running.With all water off, watch the meter for 15 minutes. Movement means a pressurized leak somewhere in the house.
- Test 2: valve closed, stops shut.If the valve has stops, close them and repeat test 1. If the meter stops, the leak is at the shower valve.
- Test 3: head aimed at the drain.Run the shower for ten minutes with spray kept off the walls. A leak points to the riser, arm or head joint, or the drain.
- Test 4: walls only.Spray only the wall tile with a handheld or cup, keeping water away from the drain. A leak points to grout, caulk or trim.
- Test 5: tub below overflow.Fill the tub partway, wait 20 minutes. A leak points to the tub drain seal.
- Test 6: tub above overflow.Fill until water enters the overflow. A leak only now points to the overflow gasket.
- Test 7: rapid drain.Pull the plug on a partly full tub. A leak as it drains points to the drain shoe or trap.
Record your results
| Test | Date | Leak seen? (Y/N) | Where and how much |
|---|---|---|---|
| 1. Nothing running | |||
| 2. Stops shut | |||
| 3. Head at drain | |||
| 4. Walls only | |||
| 5. Below overflow | |||
| 6. Above overflow | |||
| 7. Rapid drain |
Reading the results
- IfOnly tests 1 and 2 show a leakThenThe shower valve or its supply; call a plumber.
- IfOnly test 3 shows a leakThenShower arm, riser or head connection inside the wall.
- IfOnly test 4 shows a leakThenGrout, caulk or gaps around trim; resealing may fix it.
- IfTest 6 but not test 5ThenOverflow gasket.
- IfTests 5 and 7ThenTub drain seal or drain shoe.
When results are mixed
Older bathrooms can have more than one weak spot, and a wet area can take a day to show water from an earlier test. If two tests both seem positive, repeat the clearer one after the area has fully dried.
Hand the completed sheet to the plumber. Saying which test brought the leak back saves them repeating the work and makes it easier to judge whether a proposed repair matches the evidence.
Common questions
My valve has no stops. Can I still do test 2?
Skip it. A plumber can isolate the valve another way, or shut the main and check the rest of the house.
How long should the area dry between tests?
Until the stain stops growing and any damp feels dry, often a day.
Do I need special tools?
No. A flashlight, towels, a pencil for marking and access to the water meter are enough.
General information for Fullerton, not a quote or professional advice. In an emergency, call 911.