Tub Drain — Stopper Types, Removal, and Replacement Guide

A tub drain is the opening and fitting at the bottom of a bathtub through which water exits the tub and enters the drain line below the floor.

Tub Drain diagram — labeled parts, dimensions, and installation context

What It Is

The tub drain assembly includes the visible strainer or stopper at the tub floor and a drain body — a threaded flange that passes through the tub basin and connects to the drain shoe beneath. The shoe connects to the tub shoe pipe, which runs to the P-trap and on to the drain stack.

The drain assembly works in tandem with the overflow assembly: water that enters the tub either drains through the tub drain at the floor when the stopper is open, or exits through the overflow port on the tub wall if water rises too high. The two paths join below the floor at a tee fitting before reaching the trap.

Types

Tub drains are classified by their stopper mechanism. Lift-and-turn drains have a knob that you twist and push down to seal. Push-and-pull drains use a simple up-and-down action. Trip-lever drains have a lever on the overflow plate that actuates an internal plug. Toe-touch drains open and close with a toe press. Open (strainer-only) drains have no stopper; a separate plug is used manually.

Where It Is Used

Every bathtub has a tub drain. The fitting is located at the lowest point of the tub basin. It connects to concealed drain piping inside the floor or inside a wall chase below the tub.

How to Identify One

The tub drain is the round fitting at the bottom of the tub, usually 1.5 to 2 inches in diameter. It may have a visible crossbar, strainer, or knob depending on the stopper type. A separate fitting — the overflow plate — is visible higher up on the tub wall.

Replacement

Replace the tub drain when it leaks around the flange, when the stopper no longer seals, or when corrosion has damaged the finish. Many stopper inserts unscrew from the drain body and can be replaced without removing the entire drain flange. Full drain replacement requires a drain removal tool to unscrew the old body, cleaning old plumber's putty from the tub floor, and threading in the new drain body with fresh putty or silicone.

Tub Drain — FAQ

Why is my bathtub drain leaking around the edges?

A leak around the drain flange usually means the plumber's putty or silicone seal between the drain body and the tub floor has failed. The drain body may also be loose or cracked. Tightening the drain and resealing with fresh putty often resolves the leak without full replacement.

How do I remove a bathtub drain?

Most tub drains unscrew counterclockwise using a drain removal tool or a dumbbell-shaped drain key that fits into the crossbars. If the drain body is corroded or frozen in place, penetrating oil applied overnight can help. Once removed, clean the tub floor before installing the replacement.

What size is a standard bathtub drain?

Standard tub drains are 1.5 inches in diameter for the drain opening, though the outer flange may be larger. Most replacement drain assemblies are designed to fit this standard size. Confirm the measurement before purchasing a replacement to avoid returns.

Can I replace just the stopper without replacing the whole drain?

Yes, in most cases. Lift-and-turn, toe-touch, and push-and-pull stoppers attach to the drain body and can be unscrewed and swapped independently. Trip-lever stoppers involve a linkage inside the overflow tube and require slightly more disassembly, but the drain body itself usually stays in place.

Does replacing a tub drain require a permit?

Replacing the stopper or drain body in kind typically does not require a permit. Work that involves cutting into the floor, repositioning drain piping, or replacing the trap usually does require a permit and may need a licensed plumber depending on local code.