Bathroom Leak Detection

This single question drives the whole investigation. If water appears only after a shower is used, the likely candidates are the pan, the drain connection, the tub overflow gasket, or failed grout and sealant allowing water past the surface. If water is present continuously and the meter moves with everything off, a pressurized supply line or valve body is involved.

Testing follows the same logic: fill and hold the shower pan or tub to test the containment, and isolate and pressure-test the supply to test the pipe.

• Shower valve body and its wall-side connections
• Pan liner or preformed base failures, especially at the drain flange
• Tub overflow and waste-and-overflow gaskets
• Toilet flange and wax seal failures that wet subfloor and adjacent rooms
• Toilet supply connections and fill valves passing water silently
• Vanity angle stops and supply lines seeping behind a cabinet
• Failed caulk and grout allowing surface water into the substrate over time

Where the damage appears often tells you which mechanism is at work. Water on the far side of the shower wall in an adjacent room suggests something behind the wall. Damage at the threshold or at the base of the curb suggests the pan or the curb waterproofing. Damage on the ceiling below a second-floor bathroom needs the same distinction before anything is opened.