Bathtub Faucet Leaking? How to Fix a Dripping Tub Spout or Handle, and the Leak That Hides in the Wall (2026)

Three Leaks, Not One

"Bathtub faucet leaking" is three problems that share a search phrase, and they run from trivial to expensive.

The first two are an hour with a screwdriver. The third is the one that ends up in the subfloor-damage guide.

Fixing the Drip From the Spout

A faucet that drips with the water off has a valve that no longer seals. The fix depends on the faucet type:

• Single-handle (cartridge): the cartridge is worn. Shut the water, remove the handle and escutcheon, pull the retaining clip, extract the cartridge — a puller tool for stuck ones — and replace it with the exact match. Grease the new seals.
• Two-handle (compression): a rubber washer at the bottom of the stem has hardened, or the brass seat it presses on is pitted. Unscrew the stem with a deep socket, replace the washer, and dress or replace the seat.
• Ball type: the seals and springs under the ball, sold as a repair kit.

Water off first — at the tub's stop valves behind the access panel if it has them, or at the main; open the faucet to drain the line, and plug the tub drain before a screw goes down it. Parts run a few dollars to about $30; the exact match matters, so take the old part to the store.

Fixing the Leak at the Handle or Spout

Water around the handle is the O-ring or packing on the cartridge or stem — replace them while the handle is off. Water at the base of the spout when the shower runs is the spout's diverter or its seal — many spouts unscrew or release with a set screw underneath and are replaced whole. Water running *behind* the spout plate or the escutcheon into the wall is the version to take seriously: caulk the trim to the tile once the fixture is dry, and check the wall from the access side.

The Leak Inside the Wall

A tub valve lives in the wall cavity, and the spout's supply pipe runs through it. A joint that weeps, a valve body that cracks with age, or a spout that leaks back along its pipe wets the framing quietly for months. The signs: a wall around the fixtures that is soft, stained or bubbling; a damp spot or stain on the ceiling of the room below; a musty smell at the tub; mold at the surround that returns after cleaning.

Open the access panel (usually in the adjacent room or closet, behind the faucet) and run the tub and shower while watching the valve and pipes with a flashlight. Any moisture there is the real leak. This is usually a plumber's job — soldering or replacing a valve body inside a wall — and once the leak is stopped, the wet cavity follows the water damage rules: dry it, check the framing and subfloor, and replace drywall that stayed wet.

When to Call a Plumber

• The leak is inside the wall or at the valve body
• The cartridge is seized or the valve is corroded
• There are no stop valves and you are not comfortable working from the main
• The faucet is old enough that matching parts no longer exist — a valve replacement is the honest fix
• The ceiling below is already wet

Why It Matters More Than a Drip

A dripping spout wastes thousands of gallons a year — EPA's WaterSense programme puts a faucet dripping once a second at over 3,000 gallons annually — but it does not hurt the house. A leak into the wall does, on mold's 24–48 hour timeline, in a cavity nobody looks at. Fix the drip for the water bill; check the wall for the house.

Bottom Line

Spout drip: cartridge, washer or seals, an hour, water off. Handle or spout base: O-rings or the diverter. Soft wall, wet ceiling below, musty tub: the leak is in the cavity — open the access panel, then the plumber. The faucet is cheap to fix; the wall behind it is not.