How to Install a Top-Mounted Kitchen Sink

If you’re wondering how to go about installing a new top-mounted kitchen sink, you’re in the right place. This guide is meant to educate and inform. If you’re a gung-ho DIYer, it will help you accomplish your latest goal. If you’re a curious homeowner, knowing how the process works will allow you to better choose the right plumber to help with your next sink replacement. 

The first thing you’re going to need to do is turn off the water supply valves. 

If your water is still running when you attempt a sink installation, things are going to get messy fast. Look beneath your sink. You should be able to easily find the hot and cold water lines. They’ll be connected to valves you can turn counterclockwise to shut off the water. 

On the rare occasion these valves can’t be found beneath the sink, try looking in the basement. If that doesn’t work, you can just shut off your water main. The water main valve is typically found near your water heater. It’s distinguished by its bright red, rubber handle.

Turn on the faucet to let the water run out. 

When the water supply has been cut off, all the water still in the pipes doesn’t suddenly disappear. Before you do any work, turn on the kitchen faucet and let it drain. This step should only take a few moments.

Get a bucket and an adjustable wrench. 

Next, you’re going to disconnect the water supply lines with the wrench. Grip the fastener between the lines with the wrench and spin it counterclockwise until it releases. Place a bucket beneath the places you’ll be disconnecting to catch any wayward drips. 

Use a screwdriver to loosen the clamps around the sink’s underside. 

You’ll find them all around its edge underneath. Loosen them and rotate them so they’re facing towards its interior. 

Use a knife to cut the caulk around the sink. 

Any knife will do, but a utility knife or box cutter offers the most safety and control. Be careful as you cut, but make sure you’re applying enough pressure to get through the caulk. Lift your old sink out and set it aside. Clean away any leftover caulk. 

Take this time to clean any parts you’ll be reusing with your new sink. 

This includes faucets, drain, and the sprayer. 

Set the new sink into the space left by the old one. 

Hopefully you measured correctly before purchasing and it sits down comfortably in the hole. Once you set it in, remove it again – we just wanted to make sure it fit. If it doesn’t, make the needed adjustments.

Remove the sink again and flip it over. 

Now you’ll be applying the caulk to the sink’s bottom. When you set it down again, it’ll be sealed in place. Use silicone caulk for the best results. Bead by bead, place it around the perimeter, and then flip it over and lower it into the hole. If there is excess, wipe it away before it dries. 

Attach the clips on the underside of the sink. 

You’ll need your screwdriver again. Face the clips away from the sink, open mouths pointing toward the counter. Tighten them as much as you can to guarantee the sink is secure. 

Set the faucet in the hole at the top of the sink. 

Run the lines through the bottom and secure them underneath. Use plumber’s putty to seal the drain strainer in place. Do the same thing with the drain. You can make the putty malleable by rolling it between your fingers before spreading it. Remove excess putty before it dries. 

Reattach the water supply lines. 

Do the reverse of what you did to detach the lines. 

Reconnect all the pipes you removed. 

This will be as simple as rethreading things and putting them back in place so that they reconnect to the sink and its drain. 

Test it to make sure everything works. 

Turn the water supply back on and then turn the faucet. You should see water relatively quickly. If there are any leaks, now is your chance to tighten seals while you have all your tools with you. 

Voila. You just successfully installed a top-mounted sink. If this task seems beyond your current skill set, there’s no need to worry. That’s why there are professionals like the plumbers at Benjamin Franklin Plumbing out there. Call us any time for your next sink installation – we’ll be happy to help.