Tub Shoe — The Hidden Fitting Under Your Bathtub Drain

A tub shoe is the curved fitting beneath a bathtub that connects the tub drain body to the horizontal drain pipe running to the P-trap.

What It Is

The tub shoe is a short, elbow-shaped pipe fitting that receives the drain body from above — through the floor of the tub — and turns the drain flow horizontally toward the trap. It is sometimes called a tub drain shoe or drain shoe fitting. The drain body threads down into the tub shoe from the tub floor, compressing a rubber gasket between the two pieces that creates a watertight seal.

Without the tub shoe, the drain body has no pathway to the trap below. The shoe is an essential structural connector in the drain assembly, even though it is never visible in a finished installation.

Where It Is Used

The tub shoe is located directly below the bathtub floor, concealed in the subfloor cavity. It is part of every bathtub installation. Plumbers install it before the tub is set in place, because access to the underside is required for assembly.

How to Identify One

The tub shoe is not visible in a finished bathroom. It becomes visible only when the tub is removed or when there is access from below via a crawl space or open ceiling. It is the fitting that the drain body threads into, with a rubber gasket between the fitting flange and the bottom of the tub basin.

Replacement

The tub shoe rarely needs replacement on its own, but it must be replaced if it cracks, if the threads are stripped so the drain body will not tighten, or if a leak persists after replacing the drain gasket. Replacement requires either removing the bathtub or gaining access from below the floor. This is a plumber-level repair in most homes because reaching the shoe without removing the tub is difficult unless there is a crawl space or open ceiling directly below.