How To Rough In A Double Sink Vanity

Installing a double sink vanity in your bathroom is a great way to update the look of the space while also giving you more countertop and storage space. It’s a project that’s easily achievable with some basic tools and a few hours of your time.

With a little patience and some know-how, you can rough in a double sink vanity and be ready to enjoy your new look in no time.

Let’s take a look at what it takes to get the job done.

Gather Your Supplies

You’ll need all the right pieces to get this project done, so gather ’em up and let’s get started!

Make sure to have your measuring tools ready, like a measuring tape and a level. Safety gear is also essential, so don’t forget to put on some gloves and safety glasses.

Then, you’ll need to gather the supplies for the double sink vanity. This should include the vanity cabinet, two sink basins, and two faucets. Depending on the style of the vanity, you may need other items such as towel bars or a backsplash.

Once you have all the items you need, you’re ready to begin roughing in your double sink vanity.

Prepare the Plumbing Connections

Once the connections are made, you’ll be one step closer to bringing your vision to life.

To begin, measure the existing plumbing to determine the length of the pipes you’ll need. If you don’t have the necessary fittings and valves to complete the job, you’ll need to purchase those as well. Choose your pipes carefully, as they must be compatible with the existing plumbing and any additional fittings or valves. Make sure to use the right seals to ensure a tight fit and avoid any water leaks.

Once you’ve got all the necessary materials, you can begin assembling the connections. Starting with the hot and cold water lines, use the right fittings and valves to connect them to the sink drain. Connect the two faucets to the vanity with the appropriate hardware, and attach the drain line to the P-trap.

Finally, use a wrench to tighten the connections and ensure a secure fit.

Cut the Opening in the Wall

Carefully measure the space you’re working with and mark where you’ll need to cut the opening in the wall to accommodate your new double sink vanity. Make sure to measure twice, so you don’t have to worry about making any mistakes.

Once you have the measurements, use a drywall saw to cut out the opening. To make sure you’ve got the right size and shape, do a dry fit of the vanity before you secure it to the wall. This will help you make sure it fits properly, and that you don’t need to make any adjustments.

Once you’ve checked the dry fit, you can go ahead and secure the vanity to the wall. Now you’re ready to connect the plumbing and complete the installation.

Install the Supply Lines

Excitement builds as you install the supply lines for your new vanity, setting up your bathroom for a beautiful transformation. Before you begin, double check that you have all the necessary supplies, such as a shut-off valve, flexible supply lines, and a wrench.

To begin, turn off the water and open the shut-off valve closest to the sink. This will help ensure that no water escapes while you’re working.

Once the valve is on, attach the flexible supply lines to the shut-off valve and the vanity faucet. Make sure the connections are tight and secure. If you experience any water pressure issues, try troubleshooting with some of these tips: make sure the connections are secure, replace a shut-off valve with a new one, or check for any clogs in the line.

You’re now ready to install the vanity and start enjoying your beautiful new space!

Connect the Drainpipes

As you connect the drainpipes, take a moment to appreciate the beautiful transformation you’re creating in your bathroom.

Carefully connect the drainpipes to the sink drain outlet, ensuring a good seal. Use a wrench to make sure the connections are tight and secure. Use plumber’s putty or a silicone sealant to seal the connections to prevent any potential leaks.

Make sure to wipe away any excess putty or sealant before continuing. To ensure a successful installation, test the drainpipes for leaks. Run some water in the sink and check for any drips or leaks around the connections.

If you find any, use a wrench to tighten the connections further and apply more putty or sealant. If the leak persists, you may need to replace the drainpipe.

With the drainpipes connected, you’re now ready to move on to the next step of installing your double sink vanity.

Install the Vanity and Connect the Faucets

Now that the drainpipes are securely connected, it’s time to install the vanity and get your dream bathroom one step closer to completion! To ensure a smooth installation process and long-term satisfaction, make sure to:

  • Measure the vanity with accuracy to ensure it fits properly in the space.
  • Make sure the drain pipe size matches the vanity’s drain hole.
  • Carefully transfer the vanity into the desired space.

Once the vanity is in place, secure it to the wall with screws and washers. If the vanity has a countertop, make sure to seal it with silicone caulk.

Finally, connect the faucets to the water lines and you’re ready to enjoy your new double sink vanity.

Test and Finishing Touches

With the vanity fully installed, it’s time to test its functionality and add the finishing touches to your dream bathroom.

Start by testing the installed faucets, making sure they’re both on and off without leaking. If you’ve used installing tools and sealed the connections, there shouldn’t be any problems.

Next, you can add any additional accessories that you may have purchased along with the vanity. This could include towel bars, shelves, mirrors, or other items. Make sure everything is securely attached and the connections are sealed.

Finally, you can spruce up the area with a nice rug, candle, or other decorative touches to complete the look.

Frequently Asked Questions

What type of tools do I need for this project?

You’ll need a few tools to get started on your double sink vanity project.

To measure areas accurately, make sure to have a tape measure, level, and ruler on hand.

You’ll also need plumbing supplies, such as a wrench, pipe cutter, and various pipes, fittings, and connectors.

Have the necessary tools and supplies ready to go before beginning the project to ensure everything goes as smoothly as possible.

How much space should I leave between the two sink basins?

When measuring distances for a double sink vanity, it’s important to leave enough space between the two basins for plumbing connections.

The average space for two sink basins is 18 to 24 inches, with the center point of each basin being 9 to 12 inches from the other.

The exact distance will depend on the type of plumbing connections you’re using.

When in doubt, it’s best to consult a professional plumber to ensure you have adequate space between the two sink basins.

Is a rough-in necessary for a double sink vanity?

Yes, a rough-in is necessary when installing a double sink vanity.

This involves laying pipes and connecting them to the water supply.

It’s important to get the rough-in done correctly so that the vanity will be properly connected and functioning.

Doing this step correctly will help ensure your double sink vanity installation is successful.

Are there any special considerations for installing a double sink vanity in a small bathroom?

When installing a double sink vanity in a small bathroom, there are a few special considerations to take into account.

To make sure the area is waterproofed properly, you should use caulk or silicone sealant around the edges of the vanity.

Also, pay close attention to the drain assembly for the double sink to make sure it’s connected properly and won’t leak.

Following these waterproofing tips will ensure your double sink vanity is securely and properly installed in your small bathroom.

What is the best way to seal the wall around the vanity opening?

Sealing the wall around your double sink vanity installation is an important step for ensuring its longevity. The best way to do this is by using waterproofing materials that are moisture resistant.

Make sure to properly prepare the wall before you begin to apply the sealant, and use a caulk that is designed to withstand changes in temperature and humidity in your bathroom. Doing this will help protect your vanity from water damage and make sure it stays in good condition for years to come.


You’ve done it! You now have a functional double sink vanity in your bathroom.

You’ve learned how to prepare the plumbing connections, cut the opening in the wall, install the supply lines, connect the drainpipes, install the vanity, and connect the faucets.

All it takes is a little time and effort and you can have the bathroom of your dreams.

Now you can sit back, relax and enjoy your newly installed vanity. Congratulations on a job well done!

Leave a Comment