How to Install a Laundry Room Sink

Adding a laundry room sink provides convenience and functionality when doing laundry. With a sink nearby, you can easily pretreat stains, handwash delicate items, fill a mop bucket, and more. Installing a laundry sink is a manageable project for a skilled DIYer. Here is a step-by-step guide to installing a laundry room sink.

Choosing a Laundry Sink

When selecting a laundry sink, consider the size, material, style and features.


First, measure the space where you plan to install the sink. Standard laundry sink sizes range from 18 to 24 inches wide. Depth is usually around 22 inches.

For a small laundry room, an 18-inch sink will suffice. For larger spaces, opt for a 24-inch sink to allow more room for washing bulky items.


Stainless steel is the most popular material for laundry sinks. It resists stains, rust and scratches. Enameled cast iron is another durable option, but typically costs more.

Plastic laundry sinks are inexpensive, but not as sturdy over time. Solid surface sinks like quartz composite resist damage better than plastic.


Laundry sinks come in drop-in, undermount and wall-mount styles.

Drop-in sinks sit on top of the counter. This is the easiest to install style. Undermount sinks attach below the countertop for a seamless look. Wall-mount sinks attach directly to the wall, saving space.


Look for a deep basin, sloped bottom, large drain opening, stainless steel grate, and backup/overflow drain. These features will make washing easier.

Preparing for Installation

Proper planning and preparation ensures the laundry sink gets installed correctly.

Gather Supplies

You will need:

  • Laundry sink
  • Faucet
  • Supply lines
  • P-trap kit
  • Plumbing putty or caulk
  • Shutoff valves
  • Mounting hardware
  • Tools: drill, adjustable wrench, Phillips screwdriver, pipe wrench, level, tape measure

Turn Off Water Supply

Locate the shutoff valves for the hot and cold water lines under the sink. Turn them clockwise to shut off the water supply. This prevents leaks while you work.

Remove Old Sink (If Applicable)

Take out the existing sink if you are replacing an old one. Disconnect the supply lines, unhook the P-trap and remove sink rim or clips holding it in place.

Cap off open drain lines so sewer gas does not enter the room. Wear eye protection when disconnecting plumbing.

Installing a Laundry Sink

Follow these steps to install a laundry sink like a pro:

Step 1: Prepare the Countertop

For drop-in sinks, trace the sink rim on the countertop with a pencil. Cut out the opening carefully with a jigsaw.

Sand the edges smooth. Clean away dust.

Step 2: Install the Faucet

Mount the faucet on the ledge or backsplash according to the manufacturer’s guide. Don’t fully tighten it yet.

Attach the supply lines to the faucet, but do not connect them to the shutoff valves at this point.

Step 3: Mount the Sink

For drop-in sinks:

  1. Apply plumber’s putty around the sink rim.
  2. Lower the sink into the countertop opening.
  3. Press down firmly and evenly.
  4. Tighten the mounting clips below the counter.
  5. Wipe away any excess putty with a rag.

For undermount sinks:

  1. Clean the underside of the countertop and top flange of the sink with denatured alcohol.
  2. Apply silicone caulk to the top of the sink flanges rather than plumber’s putty.
  3. From below, lift the sink into place against the bottom of the counter.
  4. Attach with clips or screws drilled into the counter.

For wall-mount sinks:

  1. Hold the sink against the wall at the desired height.
  2. Trace around the mounting holes.
  3. Drill pilot holes.
  4. Attach to wall studs with lag screws and washers.

Step 4: Install Drain Piping

  1. Apply plumber’s putty around the drain hole.
  2. Slide the drain tailpiece through from below.
  3. Thread on the drain nut and tighten.
  4. Connect the trap arm to the tailpiece with the P-trap kit.
  5. Tighten all joints with a wrench.

Step 5: Connect Water Supply

  1. Attach hot and cold water supply lines to the shutoff valves.
  2. Tighten connections with an adjustable wrench.
  3. Turn on shutoff valves and check for leaks. Tighten if needed.

Step 6: Seal Edges

Fill the gap between the sink and counter or wall with silicone caulk for a watertight seal. Smooth with a wet finger.

Allow the caulk to dry overnight before using the sink.

Using and Maintaining a Laundry Sink

Caring for your new laundry sink properly will keep it looking like new.

General Usage

Avoid hard, abrasive scouring pads that can scratch the finish. Use soft sponges or rags with mild detergent for cleaning.

For stains, spray with a non-bleach cleaner and wipe gently. Rinse thoroughly.

Be aware that some items like hair dye or solvents can discolor a sink if left to sit. Rinse immediately after use.

Drain Care

Flush drains weekly by sending hot water mixed with baking soda and vinegar down the drain.

Use a drain strainer to catch hair and debris. Check it periodically and remove gunk.

Use a sink plunger or drain auger monthly to prevent clogs. Do not pour grease down the drain.

Routine Cleaning

Clean the sink weekly or more often if needed. First, remove the drain strainer.

Spray sink surface with a non-abrasive bathroom cleaner and let sit briefly. Use a soft sponge to gently wash and rinse.

For hard water spots, wipe with white vinegar. Rinse thoroughly and dry with a soft rag.

Sanitize using a dilute bleach solution. Rinse completely and air dry.

Troubleshooting Common Laundry Sink Problems

Having issues with your new laundry sink? Here are some troubleshooting tips.


Check for leaks at supply line connections and the P-trap. Tighten if needed. Apply pipe thread sealant to stubborn leaks.

If leak is at the drain, try tightening the drain nut. Reapply plumber’s putty if leak persists.

For leaks around the counter seam, apply fresh caulk and smooth with a wet finger. Allow to fully cure before use. Consider undermount sinks for leak-proof installation.

Clogged Drains

First try a sink plunger to force out clogs. Pour hot water mixed with baking soda and vinegar down the drain.

Use a drain auger or snake to remove deeper clogs. Avoid harsh chemical drain cleaners which can damage pipes.

Remove the P-trap under the sink periodically and clean out hair and debris.

Low Water Pressure

Check shutoff valves to ensure they are fully open. Disconnect and inspect sink supply hoses for blockage.

Clean the sink aerator which can get clogged. Consider a higher flow faucet if pressure remains low.


Bad smells coming from the drain are likely due to blockage or dirty P-trap. Flush with hot water and baking soda.

Pour 1/2 cup bleach into the drain at bedtime once a week. Use enzymatic drain cleaners regularly.

Make sure the P-trap always has water in it to prevent sewer gases from entering through sink drains.

Frequently Asked Questions About Laundry Room Sinks

What is the best height to install a laundry sink?

Standard height is 36 inches. For ergonomics, install the sink 2 to 3 inches lower than your elbow height.

Do I need a permit to add a laundry sink?

Permits are not required for basic sink replacement. But plumbing, gas and electrical work may need a permit. Check with your local building department.

What size is a standard laundry sink?

Most are 22 x 18 inches or 22 x 24 inches. Depth is commonly 22 inches. Measure your space before purchasing.

Can I install a stainless steel laundry sink myself?

Yes. With some plumbing experience, a drop-in stainless sink can easily be a DIY project. Undermount may be more difficult.

What type of faucet should I use for a laundry sink?

A single-handle pull-down kitchen-style faucet allows you to easily rinse laundry in the sink basin.

Should I install shutoff valves for a laundry sink?

Yes, shutoff valves on the hot and cold supply lines are necessary. This allows you to turn off water when not in use or if a leak develops.

How far should a laundry sink be from the washer?

Ideally, the sink should be within arm’s reach of the washer – no more than 36 inches away. This allows convenient transferring of laundry.


Installing a sink in your laundry room provides functionality and convenience for pretreating, handwashing and other laundry tasks. With proper planning and preparation, most homeowners can tackle a laundry sink installation successfully as a DIY project. Following the detailed steps for mounting the sink, connecting plumbing and applying caulk will ensure your new utility sink looks and works perfectly for years to come. Be sure to clean and maintain your laundry sink properly. And know how to fix common issues like clogs or leaks if they arise. A laundry sink adds value and makes laundry day much smoother.