Home Plumbing How To Install A Bathroom Sink

How To Install A Bathroom Sink

How To Install A Bathroom Sink

As a homeowner, there come times when something around the house needs a fix. In my experience, most problems I faced were quick fixes such as changing a lightbulb or a door lock. But when my old bathroom sink developed a large crack across its width, I knew it was time to install a new one. I never paid much attention to my bathroom sink, it never gave me any problems and I feel that this pointed to its quality. My old porcelain sink was almost a decade old and certainly worked well past its ideal durability period. So i decided to learn how to install a bathroom sink in no time.

In my search for a new bathroom sink, I hoped to find the same quality and durability as the old one. The task of selecting a new sink was challenging, mainly because I was spoilt for choice. There is almost an infinite number of options to choose from, such as glass, metal, and porcelain sinks. I found the concept of glass sinks appealing. These sinks are entirely transparent and look aesthetic especially if you have a good designed countertop and lighting in your bathroom. But, I decided to be practical about my choices and settled for a porcelain sink again.

My old sink was a rectangular undermount sink. When buying a new sink, it is both cost and time effective to buy one of the same size and type to have an ease of installation. Certainly, you can try any new style you want, whether it be a wall-mounted, corner style or pedestal style sink. As I said before, there are endless options to choose from.

Be mindful that different types of sinks will have different installation procedures. For a vessel sink, you’ll need to measure the required height of the faucet, ensuring it is higher than your sink. Similarly, for wall or corner mounted sinks, you’ll need ample ground clearance to install the plumbing.

Average Cost To Install A Bathroom Sink

Depending on the type and size of the bathroom sink you choose to install, your costs will vary. A new bathroom sink will cost you between $200 – $400. If you decide to buy new faucet attachments, it will add about a hundred dollars to the total cost.

Time Required

If this is the first time you will install a bathroom sink by yourself, it will take between 2 – 4 hours. Be patient while removing and re-installing your plumbing as there are various important connections. Additionally, take your time installing the sink properly to avoid future leaks.

Tools & Materials

Dismantling your Sink Assembly

Before you start to work on removing your old sink, you need to dismantle your sink plumbing first.

  • Place a bucket underneath your sink before beginning to remove connections to collect any water left in pipes.
  • Locate the hot & cold shut-off valves underneath the sink and turn them off. You can check if you have closed the valves properly by opening your faucets.
  • Additionally, remove the hot & cold supply lines connected to your faucets using an adjustable wrench.
  • Next, you will need to detach your P-trap from the sink’s drainpipe. Using a pair of pliers loosen the slip nut, which connected the drainpipe to the P-trap. Once it is loose, detach it using your hand. 
  • Similarly, remove the slip nut connecting your P-trap to the waste pipe attached to your wall. 
  • Once the P-trap is detached, clean it thoroughly using soap and water. You’ll attach it again after installing your sink.

Removing your Old Bathroom Sink

Locate the sink clips on the underside of your countertop and unscrew them. If you have an undermount bathroom sink, ask a friend to help you hold the sink or wedge row lumber under the sink while you remove the clips as the sink might drop if it isn’t held.

Similarly, if your bathroom sink is wall-mounted, corner style, pedestal, or any other style, locate the clips or bolts holding the sink in place and remove it.

Once the clips are removed, you can proceed to detach your bathroom sink from the countertop or other mounting apparatus. Remove any excess chalk on the surface using a putty knife and clean it using soap and water.

Install Your New Bathroom Sink

  • Using a power drill, create holes on the underside of the sink to attach your sink clips.

IMPORTANT TIP – Always wear protective gear such as a goggles and gloves while operating heavy machinery.

  • Apply a generous coat of silicone caulk around the underside or top of the sink, depending on the type of sink that you have.
  • If you have a drop-in sink, lower it into the sink opening on your countertop and press it firmly against the surface. Conversely, for an undermount sink, lift it towards the countertop and place planks of 2 x 4 beneath the sink to hold it in place while the caulk dries.
  • Attach your bathroom sink clips following the manufacturer’s instructions. 
  • Wipe any excess caulk on your countertop. 
How To Install A Bathroom Sink Properly

Installing your Bathroom Sink Plumbing

  • Re-connect your hot & cold supply lines to the main shut-off valves. Wrap the threaded opening at the end of the supply pipes with plumber’s tape and use a screwdriver to screw them in place.
  • Lower the lift rod into the top of the faucet. At the end of the rod, attach the clevis strap using the clevis screw.
  • Apply a generous coat of plumber’s putty on the underside of the strainer and press it against the drain opening. Wipe any excess putty using a cloth.
  • Furthermore, attach the gasket to the strainer from underneath the sink. The underside of the gasket is threaded onto which you’ll attach a washer & lock-nut.
  • Similarly, attach another gasket to the underside of the lock-nut before attaching the tailpiece mount using a wrench.
  • Make sure to align the tailpiece mount perpendicular to the clevis strap.
  • Connect the P-trap arm to the main drain pipe using a pair of pliers.
  • Similarly, you’ll need to attach the other end of the P-trap to the tailpiece.
  • The tailpiece is a small piece of pipe that connects your tailpiece mount to the P-trap. You will need to measure and cut the tailpiece according to requirement.
  • Wrap the grooved top of the tailpiece with plumber’s tape and screw it in place with the tailpiece mount. Similarly, connect it to the P-trap using a gasket and slip-nut. 
  • Lastly, lower the pop-up stopper into the bottom of the sink from the sink drain.
how to install a bathroom sink the right way

IMPORTANT TIP – Use plumbers tape at every connection. The tape forms a watertight seal between the pipes, which leads to better durability of your plumbing.

Review all the connections made above and ensure that they are firm and secure. There is one last necessary attachment you need to fit.

  • Locate the side opening on your tailpiece mount. It should be facing inward towards your wall. 
  • Slide the pivot rod ball-first into the side opening.
  • The other side of the pivot rod will be attached to the clevis strap located directly underneath your faucet mount, using a spring clip.
  • Lastly, attach the pivot nut onto the pivot rod near the tailpiece mount. To ensure the rod will hold firmly in place.

Frequently Asked Questions: How To Install A Bathroom Sink

Do I need to replace my plumbing with my sink?

You can use your existing plumbing with your new sink. Review your new sink to check if your plumbing will attach properly to the new sink’s size and type.

Does my new sink have to be the same size as the old one?

No, you have various options to choose from for your new sink both in size and type. If you choose to buy a larger sink than the old one you will need to shape your countertop to fit the new sink.


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