How to Install a Bathroom Sink Faucet and Drain
Install a bathroom faucet and pop-up drain assembly with a leak-proof seal on threads and gaskets using proper sealant techniques.
- Read the tools, materials, safety notes, and steps below for free.
- Tap Start Camera Coach when you want hands-free voice help.
- Allow camera and microphone. Point your phone at the work; the coach watches your progress and tells you the next step.
🧰 Required Tools & Equipment
- ✓ Tongue-and-groove pliers (Channel Locks)
- ✓ Adjustable wrench
- ✓ Basin wrench
- ✓ Small bucket
- ✓ Microfiber rags
- ✓ Work light
📦 Materials & Supplies
- ✓ Faucet and pop-up drain kit
- ✓ PTFE plumber's tape
- ✓ Pipe joint compound (pipe dope)
- ✓ Plumber's putty (or 100% silicone for stone/composite)
- ✓ Braided stainless steel supply lines
⚠️ Safety Checkpoints & Warnings
- • Verify angle stop shutoff valves are completely closed and lines depressurized before disconnecting old plumbing.
- • Wear eye protection when working face-up inside the dark vanity cabinet to protect from falling debris.
- • Do not overtighten brass or plastic nuts against porcelain to avoid cracking the sink basin.
📋 Step-by-Step Guide (7 Steps)
Clean Sink Surfaces and Shut Off Water
Turn clockwise to close hot and cold shutoff valves beneath the sink, then open the old faucet to relieve pressure. Clean all old putty, mineral scale, and silicone from both the top faucet holes and the drain opening using a plastic scraper and rag.
- • Porcelain around drain hole and faucet deck is smooth, clean, and completely dry
- • Water stops dripping completely from the faucet spout
- • Leaving residual crusty putty that prevents new rubber gaskets from seating flush
Mount the Faucet Body
Place the rubber or plastic deck gasket onto the faucet base, feed the flexible supply lines down through the sink deck holes, and seat the faucet body squarely. From underneath, slide the friction washers and mounting nuts onto the threaded shanks and hand-tighten, then snug them with a basin wrench or adjustable wrench.
- • Faucet base sits parallel to the back of the sink without any visible gap
- • Mounting nuts underneath are tight against washers with no body wiggle when nudged
- • Overtightening plastic mounting nuts causing them to strip or jump threads
- • Aligning the faucet crookedly before locking it down
Seal and Insert Top Drain Flange
Roll a snake of plumber's putty the thickness of a pencil and wrap it under the lip of the top drain flange (use 100% silicone if working on natural marble or composite granite). Drop the drain flange straight down into the sink's top drain hole and press firmly into place.
- • Uniform bead of putty squeezes out around the entire 360-degree perimeter of the top flange
- • Flange sits recessed and level inside the basin drain bevel
- • Using regular plumber's putty on porous natural stone, which leaves an oily permanent stain
Thread-Seal and Tighten Bottom Drain Gasket
Slide the beveled rubber gasket (cone facing UP toward sink) and friction washer onto the threaded drain pipe from underneath. Coat the pipe threads below the gasket with pipe joint compound and 4 wraps of PTFE tape over the threads where the rubber seats, then spin the large locknut up and tighten securely with tongue-and-groove pliers.
- • Beveled edge of rubber gasket is compressed uniformly into the underside sink drain opening
- • Drain tailpiece pivot hole faces straight toward the rear wall
- • Teflon tape and pipe dope visible engaging the threads directly behind and inside the nut
- • Leaving drain threads bare beneath the rubber gasket, allowing water to spiral down through helical threads
- • Installing the rubber gasket upside down with the taper facing downward
Connect Pop-Up Rod and Stopper
Drop the stopper into the drain from above, slide the horizontal pivot rod through the drain body opening to capture the stopper eyelet, and hand-tighten the pivot ball nut. Connect the lift rod strap to the horizontal rod with the spring clip and tighten the thumbscrew.
- • Stopper moves up and down smoothly when the top lift rod is pulled
- • Pivot ball nut is hand-tight plus 1/4 turn, holding water without binding the pivot rod motion
- • Missing the stopper hole with the horizontal rod, leaving the stopper loose and unlinked
Attach Water Supply Lines and P-Trap
Thread braided supply lines from the faucet shanks to the shutoff valves, hand-tightening plus 1/4 to 1/2 turn with an adjustable wrench while counter-holding the valve. Reinstall the P-trap onto the drain tailpiece using rubber slip-joint washers with the beveled side facing into the trap.
- • Braided supply lines form smooth, sweeping bends without kinks or sharp twists
- • P-trap slip nuts sit fully threaded and straight onto the tailpiece and wall tube
- • Using thread sealant tape on compression fittings or rubber gasket swivel connections
- • Overtightening plastic P-trap slip nuts until they crack
Perform Full Pressure and Drainage Leak Test
Slowly open the shutoff valves to full open, remove the faucet aerator, and run both hot and cold water for 60 seconds to flush debris. Close the drain stopper, fill the sink to the overflow hole, then release the stopper while running a dry microfiber cloth along all threaded joints, gaskets, and supply connections to check for moisture.
- • Water flushes with full, steady stream through spout
- • Dry microfiber cloth wiped under locknut, threads, and P-trap joints comes away 100% bone dry
- • Leaving the aerator attached during initial flush, which traps construction sediment inside the screen
Credit: inspired by an original tutorial by jeffostroff — watch the original on YouTube.
Don’t have everything?
- No Basin wrench? Standard open-end wrench or faucet installation socket tool included in kit
- No Pipe joint compound? Extra wraps (5-7 layers) of heavy-duty PTFE thread tape