Because they get heavy everyday use, bathroom sinks can easily become chipped, stained, or scratched over time. When this happens, you may want to install a new sink to enhance the ambience of your bathroom and create a fresh, clean look. While replacing a bathroom sink takes a bit of time, and replacing the faucet is a separate but essential element of the process, the overall job is manageable for most DIYers.
EditPreparing the Old Sink and Buying the New One
Turn off the water supply and empty the lines. The shutoff valves are usually located in the cabinet under the sink. Turn both the hot and cold valves clockwise until they resist further turning. Then, turn on the hot and cold faucet taps to empty the faucet lines.
If the shutoff valves won’t stop the flow of water completely, you’ll have to replace them. Unless you have some plumbing experience, this may be a job best left to a professional.
Disconnect the P-trap portion of the drain pipe. If the P-trap is made of PVC, loosen the slip nut that connects it to the underside of the sink drain by hand. If the P-trap is made of metal, loosen the connecting nut with channel locks.
You don’t need to remove the P-trap to replace the sink, but you may want to remove it temporarily so you can clear it of debris. To take it out, unscrew the nut (by hand or with channel locks) that connects the bottom of the P-trap to the drain line below.
Place a bucket or heavy towel at the bottom of the cabinet to catch any dripping water.
Unfasten the hot and cold water lines with a crescent wrench. These are flexible lines that run from the shutoff valves to the underside of the faucet. Disconnect them right above the shutoff valves. Some types may have nuts you can loosen by hand, but you’ll often have to use a crescent wrench.
You can reuse these water lines if you want—just disconnect them from the underside of the sink later, then reattach them during installation. But this is also a good time to replace them.
Measure the dimensions of the old bathroom sink with a measuring tape. If you want to reuse your existing countertop, makes sure you get a new sink that will fit in the same spot as the old one. Write down the length, depth, and width of the sink, as well as the length and width of the countertop.
You’ll likely have to replace the countertop as well if you want a new sink that’s a different size.
Buy your new sink at a home improvement store. Bring the measurements of the old sink and countertop with you. This helps to ensure you purchase the correct size before putting in a bathroom sink. Make sure the replacement sink is the same type (top-mount or undermount) as the old one!
Ask an employee for assistance if you need help selecting a new sink.
Most bathroom sinks are still made of ceramic, but there are other options, and many colors to choose from beyond the traditional white.
EditReplacing a Top-Mount Sink
Remove the clips under the sink that hold it against the countertop. Many, but not all, sinks have clips underneath them that create a pressure connection against the underside of the counter. If your sink has them, loosen them either by hand or with a screwdriver.
If your new sink requires clips, it should come with them. However, you may want to keep these old ones for the time being, just in case they might come in handy.
Cut any sealant between the sink and the countertop with a utility knife. Carefully run the blade of the knife between the rim of the sink and the countertop. Doing so will slice through the caulk or other sealant that secures the sink and countertop together.
Work slowly and carefully so you don’t cut into the countertop, especially if it’s made of laminated wood. Of course, if you’re replacing the countertop as well, you can be as messy as you like!
Lift out the old sink from the counter. If you can get a good grip from above, you can lift it straight up and out. Otherwise, have a second person push up from below, then lift out the sink when it pops up.
Once the old sink is out of the way, scrape away any residual caulk or sealant on the countertop. Use a plastic putty knife for scraping, then clean up any residue with a rag dipped in mineral spirits.
Install the faucet and drain on the new sink. You can either remove the faucet and drain from the old sink and reuse them, or buy a new faucet and drain to go with your new sink. If you are not experienced with this type of project, you may be better off with a new faucet and drain, since they will come with detailed installation instructions.
Faucet and drain installations will vary quite a bit based on the particular brand and model you select. However, with a good set of instructions, it is a project most DIYers can handle. Otherwise, contact a plumber.
Apply silicone caulk to the underside of the new sink’s rim. Squeeze a steady strip of caulk all the way around the underside of the rim. This will hold the sink in place and prevent water from dripping down into the cabinet.
Choose a silicone caulk intended for use with bathroom fixtures. Don’t use acrylic or other non-silicone caulks.
Lower the sink into the hole in the countertop. Lift the sink carefully and slowly drop it straight down into the opening. Once it’s in place, push down on the sink and wipe off any excess silicone that squeezes out with paper towels.
This job may be a bit easier if you have a second person reach up from inside the cabinet to support the sink from below.
Attach the sink to the underside of the counter with fastener clips. Follow the instructions that come with your new sink regarding the placement of the clips. Either tighten them by hand or with a screwdriver, as indicated by the instructions. Once secured, they’ll apply pressure to hold the sink tight to the underside of the counter.
Not all sinks require clips for installation. If your model does use clips, they should come in the package with your new sink. If you’re missing a clip or 2, it’s possible that the clips from your old sink may work.
Run a bead of caulk around the rim of the sink where it meets the countertop. Your goal here is to create a waterproof barrier between the rim of the sink and the countertop so that water can’t seep in under the sink rim. Once you’ve run the bead of caulk around the sink rim, wet your index finger and run it around the entire bead to smooth the caulk in place. Then use damp paper towels to wipe away any excess.
Use the same silicone caulk you used to adhere the underside of the sink to the countertop.
EditReplacing an Undermount Sink
Cut through the caulk that connects the sink to the underside of the counter. Reach into the sink from above and run the blade of a utility knife through the bead of caulk, all the way around the rim of the sink. Work carefully so you don’t scratch the lip of the opening in the countertop.
This caulk helps to hold the undermount sink in place but is primarily there to prevent water from getting between the sink rim and the underside of the counter.
Remove the holding clips under the sink while supporting it from below. Although it will be a tight fit in the sink cabinet, this is safer and easier with a second set of hands helping you. While the second person holds the bottom of the sink, remove the several clips (often 4-6) that pin the sink rim against the underside of the counter. They will either be screwed or epoxied into place.
If they’re attached with screws, simply use a screwdriver to remove them.
If they are stuck in place with epoxy, use a putty knife to scrape, pry, and wedge the clips apart from the underside of the counter.
Once you remove the clips, the sink will be free to fall, so make sure it’s being held up by someone!
Lower the sink down and out of the cabinet. Now that the caulk and the clips have been removed, simply guide the sink downward and out of the cabinet. If you are reusing the existing faucet and drain, remove them now. But it’s more likely that you’ll want to install new ones with your new sink.
Install the faucet, but not the drain, in the new sink. Unlike with a top-mount sink, don’t install the drain before installing an undermount sink. But it’s easier to install the new faucet now instead of having to work from inside the sink cabinet.
Installing a faucet is within the skill set of most DIYers, but the process differs based on the type and model of faucet. Closely follow the instructions that come with the new faucet.
Apply a bead of silicone caulk around the entire top rim of the sink. Use a silicone caulk designed for bathroom applications. Make sure the bead is continuous around the entire rim of the sink.
Like the stuff you removed from the old sink, this caulk is mostly there for waterproofing, but also helps hold the sink in place.
Secure the sink in position with a piece of lumber and a bar clamp. Cut a section of lumber so it’s at least a few inches/centimeters longer than the width of the opening for the sink in the countertop. Lay this piece of wood across the opening. Then, while a second person lifts the new sink up into place from beneath, feed the bar clamp up through the drain opening of the sink so that one of its clamps holds up the sink from below. Secure the other clamp to the piece of wood and tighten it.
Make sure the clamp is tight enough to make the some of the silicone caulk squeeze out between the rim of the sink and the underside of the counter. Wipe away this excess caulk with a damp rag.
Secure the included clips in place with screws or epoxy. Your new undermount sink will come with support clips to place around the underside of the sink where it meets the underside of the counter. In some cases, these clips may attach with screws. If so, drill pilot holes and use a screwdriver to secure the clips in place. Otherwise, use the brand or type of epoxy recommended by the sink manufacturer.
In most cases, the clips are adhered in place with a 2-part epoxy that hardens in about 10 minutes after being combined. Follow the product instructions carefully and apply the proper amount to each clip. Then press them into place as per the installation instructions for your sink.
Wait 24 hours, then install the drain. Even though the epoxy should be fully set in 10 minutes, it’s important to give the silicone adhesive time to cure fully. Leave the piece of lumber and bar clamp in place for a day before removing them. After that, you can put the drain in place and continue with the installation.
Like faucets, drain installations vary by type and brand, but the process is DIY-friendly if you follow the instructions carefully.
You could rely on the epoxy to hold everything in place after 10 minutes and not wait the full 24 hours before proceeding, but this is not recommended. Be patient!
EditMaking Final Connections and Testing
Allow the caulk on a top-mount sink to cure for 24 hours. Instead of making the final connections right away, it’s better to give the silicone caulk time to set up. This will prevent the sink from shifting and breaking the solid bead of caulk that you made.
If you’re installing an undermount sink, you should already have waited 24 hours before putting in the sink drain. In this case, you can proceed with the last steps of the installation.
Reconnect the water lines and the P-trap underneath the sink. You just need to do the reverse of the disconnecting process. Hand-tighten the water lines where they connect to the hot and cold shutoff valves or use a crescent wrench if needed. Similarly, use your hands to tighten the nut on a PVC P-trap or channel locks for a metal P-trap.
If your new sink drain is a little shorter than your old one, you can buy a P-trap pipe extension at your local hardware store. The extension can be cut to fit and will also connect in place with a nut that you’ll either hand-tighten or secure with channel locks.
If your new sink drain is a little too long, you can cut off some of the pipe either at the top of the P-trap or the bottom of the drain. Use a hacksaw or pipe cutter to make the adjustment.
Turn the water back on and check for leaks. Open the hot and cold water valves by turning them counterclockwise. Then, open the hot and cold faucet taps fully and let the water run for at least 2-3 minutes. Watch under the cabinet for any leaks in the water lines, drain lines, or elsewhere. Tighten any loose connections as needed.
Keep the bucket or towel at the bottom of the sink cabinet while you test for leaks.
If you have a leak at a pipe connection, try shutting off the water, undoing the connection, wrapping some plumber’s tape around the pipe threads, and then re-making the connection.
If you can’t figure out where a leak is coming from and/or how to fix it, shut off the water supply lines and call a plumber.
EditThings You’ll Need
Pencil and paper
Channel lock pliers
Piece of lumber (for undermount sink)
Bar clamp (for undermount sink)
2-part epoxy (for undermount sink)
Replace a Bathroom Faucet
Install a Bathroom Sink
Repair a Delta Brand Kitchen Faucet
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EditSources and Citations
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