Installing a pedestal sink
Before a pedestal sink takes its place, the wall behind it needs to be shored up to hold its weight. Then the installation goes easy.
To install a pedestal sink you need the following material:
- Adjustable wrench
- Electric drill
- Measuring tape
- Pedestal sink with mounting bracket
- P-trap, tailpiece, and slip-nut fittings
- Ratchet with sockets
- Scrap plywood or 2-x-10 for blocking
- Wood screws
Mounting the sink to the wall
After the wall is reinforced and repaired, the sink can be installed. Some sinks require a separate bracket that is installed first, but others mount directly to the wall. These directions are for a sink with a bracket. You can skip those steps if the sink you’re installing doesn’t have a bracket. Figure 1 shows a typical installation.
1. Position the bracket on the wall and use the bracket as a template to mark the location for the mounting lag bolts.
To find the exact location of the mounting bracket, consult the roughing-in dimensions provided by the manufacturer.
Make sure the bracket is level.
2. Drill pilot holes through the layout marks on the wall into the wall reinforcement.
Make the holes about 1/8 inch smaller than the lag bolts supplied by the manufacturer. Lag bolts are large screws with a square or hex head.
3. Install the bracket with the lag bolts.
4. Hang the basin on the wall bracket and then install the additional mounting screws to hold the sink to the bracket and wall.
If the sink does not have a mounting bracket, install it directly to the wall with the fasteners provided by the manufacturer.
5. Test-fit the pedestal, mark its location, and then move it safely out of the way.
Installing the P-trap
With the sink on the wall, you can now install the P-trap. The P-trap is the pipe that connects the sink to the house drain. The U-shape of this pipe is the trap that retains enough water to prevent sewer gases from entering the bathroom. The P-trap is adjustable and can slide up and down on the pipe leaving the sink drain. The other end of the P-trap can also slide in and out of the fitting on the wall.
To install the P-trap, you may have to cut the tailpiece that protrudes from the pop-up assembly if the P-trap doesn’t align with the drain that comes out of the wall.
Referring to Figure 2, follow these steps to install the P-trap:
- Slide the short side of the P-trap onto the tailpiece that drops down from the sink drain. Move the P-trap up or down to align the trap arm with opening in the wall.
Use a hacksaw to cut the tailpiece shorter whenever the P-trap can’t be moved higher up the tailpiece and the trap arm is below the wall drain fitting. Purchase a longer tailpiece whenever the P-trap is above the wall drain fitting when attached to the end of the tailpiece.
- Take the lower part of the P-trap apart and insert the trap arm into the wall drain fitting as far as it will go.
- Pull the trap arm out of the wall fitting until it aligns with the top of U-shaped portion of the trap.
If the trap arm comes completely out of the wall before it can be attached to the trap, purchase a longer trap arm. If the rap arm is in the wall fitting as far as it will go and extends past the U-shaped part of the trap, cut it shorter with the hacksaw.
- Insert the trap arm back into the wall drain, move it into alignment with the trap, and thread on (but don’t tighten) the slip nut.
- When the trap parts are joined together, tighten the slip nuts on the tail piece and the wall drain fittings.
Attaching riser tubes to the faucet
After the P-trap is installed, you can turn your attention to attaching the riser tubes (supply lines) to the faucet tailpieces, using the compression nuts that came with the faucet. See Figure 2
The riser tubes connect the faucet to the stop valves. Here are a couple of pointers for attaching the tubes to the faucet:
- Snug up the nuts by hand
- Bend or loop the riser tubes so that they fit between the stop valves and the wall before tightening them with a wrench.
The moment of truth has arrived; you have to turn the water at the shut-off valves and the faucet and test for leaks in the supply lines and fittings leading to the faucet and in the drain lines and fittings. When everything is drip free, you can install the pedestal by simply positioning it properly beneath the sink and securing it to the floor with a wood screw.
Don’t over tighten the pedestal mounting screw because doing so may crack the pedestal base.
Last, you can caulk any gaps or voids between the wall and the basin and remove any excess caulk with a wet rug.