How to Install a Vessel Sink Drain without Overflow

Bathroom vessel sink drain installation is an important step to completing your bathroom. Vessel sinks are stylish lavatories that can be very eye-catching, but they have a few unique issues that must be addressed. Because they sit above the surface of the sink cabinet below, they often do not have an overflow drain.

If you are used to filling your sink bowl full of water, this could present a problem. Most bathroom sinks use pop-up drains that connect with an overflow for proper drainage.

A vessel sink that lacks this feature will need a special type of drain system that does not require an overflow hookup. The main drain should be able to empty the sink quickly and efficiently to avoid any messes.

Overall, one of these types of sinks can look striking inside any bathroom. An overflow in this type of sink may actually be unsightly, which is why many vessel sink bowls lack one. Installing a vessel sink without the overflow is easy if you have the right tools and proper skill.

6 Steps to Install a Vessel Sink Drain Without Overflow:

Materials Needed:

  • Pop-up drain
  • Silicone waterproof putty
  • Putty gun or knife
  • Pencil or chalk
  • P-trap
  • Plumbers glue
  • Wrench
  • Leveling tool
  • Hacksaw
  • Mounting ring (optional)


Always turn off water at the primary source before installing anything plumbing-related.

Step One: Choose the Proper Drain

To install a bathroom vessel sink drain without overflow, you will need to start with the correct drain. Pop-up drains are recommended, since they can be plugged or unplugged as needed. Grid drains are fine, but be sure the holes are large enough to enable quick drainage.

Grid drains cannot be plugged, so if that is a necessary feature you may prefer the pop-up drain. A soft-touch pop-up drain does not require a lever and can be opened or closed by pressing down on the top of the drain.

Pop-up drains also have shorter plumbing lines since they do not connect to the overflow. This shorter pipeline will also enable good drainage. This feature is necessary when an overflow drain is absent.

Step Two: Set Your Sink in Place

Line up your sink with the vanity below by using the drain holes as a guide. Mark the edges with pencil or a piece of chalk so you will have a visual guide. Turn over the vessel and apply a bead of waterproof silicone putty to the bottom edge.

Using your previous marks to guide you, position your vessel sink once again into place over the vanity drain hole. Take a few extra minutes to make sure these two holes line up exactly before the silicone putty dries.

If any excess caulk oozes out of the edge, allow it to dry before cleaning it up. It can be easily peeled away with a putty knife after it has time to set up.

Take your leveling tool and make sure your vessel sink is positioned evenly on the flat surface. Make adjustments as necessary before the caulk dries.

Allow the silicone caulk to dry completely before proceeding to next step.

Note: If installing a glass vessel sink, you will need to use a mounting ring prior to caulking. Because glass sinks can be handmade and therefore uneven on the bottom, a mounting ring will make the sink’s bottom sit flush with the cabinet below. After installing the mounting ring, you can then proceed to position the sink into place as stated above.

Step Three: Insert Drain

Many sinks come with drains and assemblies that fit that particular model. However, you may need to purchase a drain separately.

When a vessel sink does not have an overflow drain, that means that the main drain you install should not have a connection to a separate exit. Not having this extra component can make installation quick and easy if you install the correct drain.

Apply a bead of waterproof sealant around the drain hole. Using the proper drain model, thread the drain through the vessel sink and into the vanity below. The drain should fit snugly into the hole, and enough sealant should be used to affix and seal the drain completely.

From under your vanity, you should also be sure the rubber gaskets and other mechanisms fit tightly to the bottom of the sink. Do not overtighten the drain, as doing so could cause problems or even crack your vessel sink if it is made from a material like glass or ceramic.

Step Four: Install Faucet and Handles

When installing a sink, a faucet is usually installed separately from the sink bowl itself. However, the spigot and its handles still hook up to the drainage system below.

Whether you are using a single-lever faucet or a double handled model, now is the time to install them according to the manufacturer’s instructions. Be sure to hook up the hot and cold lines properly to the correct handles. Be generous with the sealant, as you do not want any leaks or seepage down the line.

Step Five: Connect Drain to Plumbing Pipes Underneath Vanity

During your bathroom vessel sink drain installation, you will need to finally connect your drain to the sink bowl.

After you have securely installed the upper portion of the drain, it’s time to look under the vanity. If the drain pipe is too long for the area under the vanity, use your hacksaw to adjust the length.

Connect the pipe that extends straight out of the bottom of the drain to a P-trap. The end of each pipe should be threaded and they will screw onto one another easily.

The main pipe that runs into your wall should then be attached to the other end of the P-trap. Use the plumber’s glue to make sure these two ends are airtight and waterproof.

You can also use your wrench to make sure each item is secured tightly, but do not overtighten. Overtightening these connections could result in cracks or leaks.

Final Step

Turn on the water at the primary source and check for leaks or problems above and below the sink. Test the drain by filling the sink and then draining it completely. The water should quickly drain out without delay.


Hopefully, now you know how to install a vessel sink without overflow. Without additional features, a special drain should be used that is shorter on the plumbing side. Quick and complete drainage is essential in a sink that lacks an overflow.

While grid drains can be useful, they cannot be stoppered which may be inconvenient. Pop-up drains, on the other hand, enable you to fill your sink as needed.

Care should be taken with this extra capability since it means that your sink could get too full and create a mess. A soft-touch pop-up drain will allow you to quickly open the drain in case you need the sink to be emptied in an emergency.

With the right tools, it’s easy to install without overflow. Because they are positioned above a vanity, vessel sinks can be convenient to work with when performing installation, especially without an overflow.

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