How to Install a Bar Sink Drain? | 4 Steps That Work

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Install a bar sink drain by seating the strainer through the sink opening, tightening the lock nut below, and connecting the tailpiece and trap.

The process for how to install a bar sink drain follows the same logic as a kitchen sink drain, only with smaller parts and tighter working space. It’s a doable afternoon project with basic tools, and most of the work happens underneath the sink. Most bar sinks don’t ship with the drain assembly included, so check the box before you start. You’ll need the strainer, sealing washers, lock nut, tailpiece, and trap, plus plumber’s putty if the instructions call for it. If the sink is already mounted, read through the steps once so you know which side of the cabinet to work from.

Parts You’ll Need

Four parts make up a standard bar sink drain kit:

  • Strainer or drain basket — the visible flange that sits in the sink opening.
  • Rubber sealing washer and paper gasket — the two layers that seal the underside.
  • Lock nut — the threaded ring that pulls the strainer tight from below.
  • Tailpiece or drain pipe — the section that connects the strainer body to the trap.

The exact order of the rubber washer and paper gasket varies by manufacturer, so follow the sheet that came with the kit. Getting that order wrong is a classic leak source. Some kits include plumber’s putty, and some don’t; pick up a small can if yours doesn’t. You’ll also want a basin wrench for the lock nut, slip-joint pliers for the trap nuts, and a flashlight for cabinet work.

Bar Sink Drain Installation Steps

Install the drain in four steps that take about 30 minutes. If the sink isn’t mounted yet, do this before you set it in the cabinet; the job is far easier on a countertop. Work with the sink upside down on a protected, flat surface, and get a second person involved if the sink is heavy — one American Standard guide says plainly not to attempt large sinks alone.

  1. Insert the strainer through the sink opening from the top side, with the flange seated against the basin. Center it so the flange sits level.
  2. From underneath, slide the rubber sealing washer and paper gasket over the strainer body, then start the lock nut by hand.
  3. Tighten the lock nut with pliers or a basin wrench just until the strainer draws snug against the sink bottom. Over-tightening distorts the gasket and causes leaks.
  4. Attach the tailpiece to the strainer body, connect the trap, and line everything up with the wall stub-out before final tightening. A twisted joint is the most common leak source.

Before you tighten the trap, dry-fit the whole run and check alignment. The pipe should line up with the wall stub-out without being forced into place. If it won’t, loosen the slip joints and reposition instead of cranking down on a stressed fitting.

Once the joints are tight, run water and check underneath. Keep a bucket under the trap and let the water run for a full minute before you call it done. If water seeps around the flange, the standard fix is a thin rope of plumber’s putty under the flange or a bead of silicone, then re-tighten. If the leak is at a joint, the pipe is usually misaligned or the nut is loose. Some portable bar systems need extra steps after this point, like drain-to-tank alignment and pump connections, but those are system-specific steps rather than general sink-drain work.

What Size Drain Does a Bar Sink Need?

Sink openings vary too. Measure the hole across the opening before ordering a strainer so the flange covers it completely.

If you’re replacing rather than rebuilding, our tested roundup of the best bar sink drains covers kits that fit standard openings.

FAQs

Does a bar sink drain come with the sink?

Often not. Many bar sinks are sold without the drain assembly, and the instruction sheet tells you to install a drain according to the faucet or sink manufacturer’s directions. Check the parts list before you begin so a missing strainer or lock nut doesn’t stall the job.

What size drain pipe does a bar sink use?

Measure the sink hole before buying a strainer.

Can plumber’s putty fix a leaky bar sink drain?

Yes, in most cases. If the flange leaks around the sink opening, remove the strainer, roll a thin rope of plumber’s putty under the flange, and re-tighten. Silicone also works on some materials. Wipe away any squeeze-out after the lock nut is snug.

References & Sources

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