How to Install a Pedestal Sink
About This Project
This guide provides comprehensive, step-by-step instructions for removing an existing sink and installing a new pedestal sink. The process covers preparing the space, assembling the faucet and drain on the new sink basin, securely mounting the basin and pedestal, and connecting all the plumbing for a leak-free finish.
Best for experienced DIYers and homeowners with some experience with basic plumbing knowledge and familiarity with power tools.
Tools & Materials
Adjustable Wrench
Channellock 10 in. Tongue and Groove Plier 430
Husky Pro Utility Knife 00004
HDX 3-1/4 in. 6-in-1 Screwdriver 120SD12D
Unger 6 Gal. Heavy-Duty Plastic Bucket DB02
THE CLEAN STORE Pink/White Microfiber Towels (Pack of 600) 79136C
Adjustable Wrench
Fits various nut and bolt sizes with its adjustable jaw.
Channellock 10 in. Tongue and Groove Plier 430
The Channellock 10 in. Straight Jaw Tongue and Groove Pliers are constructed with high-carbon steel and fashioned with laser heat-treated teeth for strong, nonslip jaw action. Undercut tongue-and-groove
Husky Pro Utility Knife 00004
Offering a precise cut every time, Husky Pro Folding Utility Knife lets you easily adjust the blade to multiple angles to tackle a wide range of jobs. Aluminum die casting handle with plastic spraying
HDX 3-1/4 in. 6-in-1 Screwdriver 120SD12D
The HDX 3-1/4 in. 6-in-1 Screwdriver features double-sided bits with the four most common screwdriver tip styles, including a #1 Phillips bit, a #2 Phillips bit, a 3/16 in. flathead bit and a 1/4 in. flathead bit. Both ends of the shaft can be used as 1/4 in. nut drivers when the bits are removed, offering convenient, versatile use. The high-visibility orange handle makes the handy tool easy to find on a job site or in a toolbox.
Unger 6 Gal. Heavy-Duty Plastic Bucket DB02
The Unger 6-Gallon Heavy-Duty Professional Cleaning Bucket holds more than 6 Gal. of liquid. The bucket can accommodate a scrubber up to 14 in. L. This bucket features measurement marks and 2-pour spouts
THE CLEAN STORE Pink/White Microfiber Towels (Pack of 600) 79136C
The Pull N Wipe Microfiber Cleaning Rags are the ideal cleaning cloths. Perfect for all your cleaning needs. These cleaning cloths come in prepackaged dispenser boxes to make your cleaning experience a convenient one.
Steps
Preparation and Removal of Old Sink
45 minsBegin by preparing the workspace. Place a bucket under the existing sink's P-trap to catch residual water. Use an adjustable wrench to turn the hot and cold water shut-off valves clockwise until they are fully closed. Turn on the faucet to release any remaining pressure and water. Use channel-lock pliers or an adjustable wrench to disconnect the hot and cold water supply lines from the shut-off valves. Next, disconnect the P-trap from the sink's tailpiece and the drainpipe in the wall. If there is a vanity, it will need to be removed. Carefully cut the caulk seal along the backsplash and sides with a utility knife. Locate and remove the screws securing the old sink or vanity to the wall. With the help of another person, lift the old sink and vanity away. Thoroughly clean the wall and floor area where the new sink will be installed, removing any old caulk or adhesive.
Assemble Faucet and Drain on Basin
30 minsBefore mounting the sink, install the faucet and drain assembly. Place the new sink basin upside down on a soft surface like a towel or cardboard to prevent scratching. Follow the faucet manufacturer's instructions. Typically, you will insert the faucet tailpieces through the holes in the sink basin and secure them from underneath using the provided nuts and washers, tightening with a basin wrench. For the drain, apply a ring of plumber's putty or a silicone bead under the drain flange. Insert the drain body through the drain hole from the top of the sink. From underneath, install the gasket and retaining nut onto the drain body and tighten it securely. Attach the pop-up drain linkage if included. Clean off any excess plumber's putty from the basin.
Mark Mounting Hole Locations
30 minsDetermine the final height of the sink (standard is 32-34 inches from the floor to the rim). Place the pedestal in its final location. Carefully set the sink basin on top of the pedestal. Press the sink basin level against the wall. Use a torpedo level to ensure the basin is level both side-to-side and front-to-back. Once level, trace the outline of the back of the sink basin onto the wall with a pencil. Also, mark the locations of the mounting holes through the back of the sink. Set the sink and pedestal aside. Use a stud finder to locate the wood studs behind the marked hole locations. If the holes line up with studs, drill pilot holes appropriately sized for the lag screws provided with the sink. If they do not align with studs, you will need to install a wood cross-brace behind the drywall, which is a more advanced task. For this guide, we assume alignment with studs.
Mount the Sink Basin
20 minsInstall the mounting hardware into the pilot holes you drilled. Most sinks use lag screws with washers or specialized hanger bolts. Screw the lag screws into the wall studs, leaving them protruding enough to hang the sink basin on (about 1 to 1.5 inches). With a helper, carefully lift the sink basin and guide the mounting holes onto the protruding lag screws. Thread the washers and nuts onto the lag screws but do not fully tighten them yet. The sink should be supported by the screws but still have some movement.
Position Pedestal and Secure Basin
15 minsCarefully slide the pedestal base under the loosely mounted sink basin, aligning it with the bottom of the basin. The pedestal's primary role is support, not bearing the full weight, which is handled by the wall bolts. Check again that the sink basin is level side-to-side and front-to-back using your level. Make any necessary adjustments by slightly moving the sink on the bolts. Once everything is perfectly aligned and level, fully tighten the nuts on the lag screws to secure the sink basin firmly to the wall. Alternate tightening the nuts to apply even pressure. Some pedestals have holes in the base for securing it to the floor with screws; if so, mark these holes, move the pedestal, drill pilot holes, and secure it to the floor.
Connect the P-Trap and Drain
20 minsNow connect the drain plumbing. Attach the P-trap to the sink's drain tailpiece. The P-trap kit will include slip nuts and washers. Ensure the washers are oriented correctly (tapered side towards the threads). Align the other end of the trap with the drain pipe in the wall and connect it. You may need to trim the pipe from the wall or the tailpiece from the sink for a perfect fit, which can be done with a hacksaw or tubing cutter. Hand-tighten all the slip nuts first to ensure proper alignment, then give them a final quarter-turn with channel-lock pliers. Do not over-tighten plastic fittings.
Connect Water Supply Lines
15 minsAttach the new flexible water supply lines to the threaded tailpieces of the faucet. Hand-tighten the nuts. Then, connect the other ends of the supply lines to the hot and cold water shut-off valves on the wall. The hot line is typically on the left and the cold on the right. Use two wrenches to tighten these connections: one to hold the shut-off valve steady and the other to tighten the supply line nut. This prevents putting stress on the plumbing in the wall. Tighten until snug.
Test for Leaks and Apply Caulk
20 minsWith all connections made, it's time to test for leaks. Place dry paper towels under all connections (supply lines and drain trap). Slowly turn on the shut-off valves, one at a time, and let the water run. Use a flashlight to carefully inspect every connection point for any sign of dripping. Check the connections at the shut-off valves, at the faucet tailpieces, and all joints of the P-trap. Fill the sink basin completely, then release the pop-up drain to let the water rush out. This pressure-tests the drain connections. If any leaks are found, turn off the water and gently tighten the leaking connection a little more. Once you've confirmed there are no leaks, apply a bead of silicone caulk along the back edge of the sink where it meets the wall and around the base of the pedestal where it meets the floor. This seals gaps and adds stability. Smooth the bead with a wet finger or caulk tool.
Common Problems
Leaking sink strainer connection.
Solution: Ensure you use the correct beveled gasket for the connection to the sink strainer for a proper seal.
Cracked plastic fittings from over-tightening water supply lines.
Solution: Hand-tightening is usually sufficient for these plastic fittings. Over-tightening with a wrench can crack them.
Sink connections won't seal if PVC cement dries before assembly.
Solution: Work quickly once you apply PVC cement, as it sets fast.
Ensure adequate ventilation when working with PVC primer and cement, as the fumes can be strong.
Solution: To avoid this issue: Be mindful of this warning and take appropriate precautions.
Overtightening plastic slip nuts can strip threads or cause cracks.
Solution: Most plastic slip nuts are designed to be hand-tightened and loosened.
Ensure that the slip-joint washers are installed with the tapered side facing the direction of the fitting it is sealing against.
Solution: To avoid this issue: Be mindful of this warning and take appropriate precautions.
Per plumbing code, ensure there is a straight pipe section of at least two times the pipe diameter between the P-trap and the vent tee (TY).
Solution: To avoid this issue: Be mindful of this warning and take appropriate precautions.
Frequently Asked Questions
Do I really need all the specific tools listed, like the Hilti drill and Zircon stud finder?
For secure and accurate installation, a stud finder is highly recommended to ensure the basin is mounted to wall studs, preventing wobbling. While the Hilti drill is powerful, any corded hammer drill with appropriate masonry bits can work for drilling into tile or plaster if studs aren't accessible or for floor mounting, but ensure it's capable of making clean holes.
What's the most critical safety precaution to take before starting this pedestal sink installation?
The most critical step is to turn off the water supply to the entire house or at least the bathroom you're working in. This prevents accidental flooding when disconnecting old fixtures or if a new connection leaks during testing. Always double-check that the water is off before proceeding with any plumbing disconnections.
How long should a beginner expect this project to take, and what's a common time-consuming step?
For a beginner, plan for a full day (6-8 hours) for this project, especially if you're unfamiliar with plumbing. Removing the old sink, particularly if it's heavily caulked or secured, can often be the most time-consuming initial step. Take your time, as rushing often leads to mistakes.
What's the most common mistake beginners make that causes leaks after installation?
The most common mistake is not properly tightening or sealing the P-trap and water supply connections. Ensure all threaded connections are hand-tightened, then given an additional quarter to half-turn with pliers or a wrench, and always use plumber's tape or pipe dope on threaded water supply connections for a watertight seal.
How can I ensure my new pedestal sink is perfectly stable and doesn't wobble after installation?
Stability comes from two main points: securely mounting the sink basin to wall studs and leveling the pedestal base. Use your stud finder to locate and mark the studs accurately for the basin mounting screws. For the pedestal, adjust its position and use shims if necessary to ensure it's level and makes firm contact with the floor before connecting the basin.
Is the specified SnappyTrap Universal Drain Kit essential, or can I use a different type of P-trap?
While the SnappyTrap is designed for easy installation, a standard P-trap kit is perfectly acceptable if you prefer. Just ensure the P-trap you choose is compatible with your sink's drain opening and wall drain rough-in, and that it comes with all necessary washers and nuts for a leak-free connection.
What should I look for when buying the pedestal sink to ensure it's compatible with my existing plumbing rough-ins?
Before purchasing, measure the height of your existing drain pipe from the floor and the spacing of your hot and cold water supply lines. Compare these to the new pedestal sink's specifications, particularly the drain opening and faucet hole placements, to minimize the need for plumbing modifications.
