DIY Bathroom Vanity
There are two types of basins (sinks): bathroom basins, which fit 1-1/4” drains; and bar basins, which fit 1-1/2” drains. Most bathroom faucets incorporate a 1-1/4” pop-up drain assembly. Depending on the sink you choose, you may have to purchase a separate drain assembly. Be sure your sink and faucet set are compatible.
When looking for a wooden cabinet or dresser to convert into a vanity, pay close attention to the dimensions of the cabinet. Ideally, purchase your sink first so that you can choose a cabinet with the right dimensions – something that is wide and deep enough to accommodate the sink, leaving space at the back of the cabinet to fit a faucet set as well as space at the front of the cabinet so that the sink doesn’t run up to the front edge. The cabinet should also be approximately 32” high – standard vanity height.
If you’re converting a cabinet with shelves or a dresser, you’ll probably have to cut through the back and bottom of the shelves or drawers to accommodate plumbing parts and pipe. This will make the drawers somewhat unstable, so you may need to fix the top drawer permanently in place by screwing it to the frame of the cabinet from beneath, filling the screw holes and touching them up with paint or stain. If you really want to use the drawers that have parts cut out of them, consider lining them with plastic baskets so smaller items do not fall out the back or bottom.
Materials and Tools
- Pencil and ruler
- Sharp utility knife
- Masking tape
- Electric drill with 1” drill bit
- Faucet set
- Paintbrush, or roller and tray
- Water supply lines
- Drain assembly
- Chrome P trap (may be supplied with the sink)
- 2-1/2” hole saw*
*Available at tool rental companies
Step 1: Make sink hole template
Many sinks come with templates to help guide you in cutting the hole in the vanity top. If your sink does not come with a template, make one yourself from cardboard. Set the sink upside down on a piece of cardboard and trace around the lip of the sink onto the cardboard with a pencil. (See Photo 2) This will be the template for cutting the sink hole in the top of the cabinet.
Step 2: Cut sink hole
With masking tape, securely tape the cardboard template to the top of the cabinet in the spot where you’d like the sink to be situated. With a 1” drill bit, drill a hole into the cabinet, just inside the cardboard template. This hole will enable you to get the jigsaw started. With a jigsaw, cut the sink hole, following the hole in the cardboard template as you go. (See Photo 3)
Step 3: Drill faucet holes
To determine the faucet placement, drop the sink into the cut sink hole – you can gauge by eye the best location for the faucet. Remove the sink. Centre the faucet set on the cabinet just behind where the sink will sit. Mark the spot with masking tape. With a pencil, mark the tape with the location of the faucet spout and the 4” centre-to-centre tap measurement (i.e. 2” to either side of the faucet spout). Drill the holes for the faucets at those points 4” apart using a 1” drill bit.
Step 4: Varathane vanity top
With a paintbrush, or roller and tray, apply several protective coats of clear Varathane to the top of the vanity. Be sure to Varathane the cut edge of the sink hole as well; this will seal the wood and protect it from water seepage and wetness. Allow Varathane to dry completely before proceeding.
Step 5: Cut holes in cabinet back
To determine the position of the drain pipe and water supply shut-offs on the back of the cabinet, measure their locations on the wall and transfer these locations to the back of the cabinet. Using a 2-1/2” hole saw, cut holes in the back of the cabinet to accommodate the drain pipe and the water supply shut-offs. (The holes must be big enough to clear the handles of the shut-offs.) Install cabinet against wall.
Step 6: Attach faucet
Turn off the water supply shut-offs. Drop in the faucet set and tighten it into place from underneath. The faucet set will come with all the necessary parts (i.e. washers, rubber rings, etc; see our Materials picture for assembly parts). With faucet set firmly in place, attach the water supply lines. Connect these to the water supply shut-offs coming out of the wall, and tighten. (See Photo 6)
Step 7: Install drain assembly and sink
Depending on the sink you use, the drain assembly parts will be 1-1/4” or 1-1/2”. We used a bar sink, which required a 1-1/2” drain assembly. (Bathroom sinks will need a 1-1/4” pop-up assembly, which should come with a bathroom faucet set.) Set the drain into the sink, attach the rubber washer and nut onto the drain beneath the sink, and tighten. Screw on the tail piece. Drop the sink into the sink hole. Our sink had clips to hold it into place.
Step 8: Attach P trap
Attach the P trap onto the tail piece and to the trap adapter coming out of the wall. (See Photo 8) The drain assembly will determine the size of the P trap (i.e. either 1-1/2” or 1-1/4”). Turn on the water supply shut-offs.
Step 9: Modify dresser drawers
Measure and mark on the drawers from the back of the cabinet to the front point of the P trap. As well, mark the locations and the widths of the water shut-offs; the drawer will need to clear these too. With a jigsaw, cut out the back and bottom of the drawers according to these measurements so that the drawers can now adequately clear all plumbing parts, water shut-offs and adapter. (See Photo 9) Slide the drawers back into place. (See Photo 10).