How to Install a Sink Cabinet Base

Sink cabinets make convenient storage spots. Kitchen sink cabinets can store cleaning supplies, trash bins, or garbage disposals, and bathroom sinks can store paper goods, towels, or toiletries.

These cabinets or vanities don't usually have drawers across the top, as the recessed bowl of the sink wouldn't allow the necessary space for them. Many have drawers on one or both sides, though. The opening directly in front of the sink usually features, doors, but it can be covered with a curtain for a more simple solution.

If you want a pre-fab solution, you can purchase a sink cabinet to fit the available space. If you have some basic carpentry and plumbing skills, though, you can also build one yourself.

Step 1 - Prepare the Sink Space and Materials

For a smooth, sane installation experience, start by clearing the space around which you'll be working. The plumbing may run through the walls or directly below the sink through the floor.

Measure the width at the base. Make a note of the relative positions of the drain pipes and water lines, and the width of the base. Get a sink cabinet and countertop to fit if it's a bathroom vanity.

Units with pipes running directly below the sink will already have holes in the base of the sink cabinet. If you want to paint the cabinets, it would be easier to do that before installing them.

Step 2 - Preparing to Install

Before starting the work on the base cabinet, you should remove all the drawers and the doors, especially since most of them come equipped with "clip-on" hinges.

Along with making the cabinet lighter and easier to work with, it will provide you extra room to work inside the cabinet and avoid possible scratches or other damages to those components.

Shut off the water supply and remove the plumbing, then the old sink. Without securing anything down, place the cabinet exactly where you want it against the wall then adjust it perfectly level and stable on the floor. Unless the cabinet is shoved right up against a corner, mark the placement of the cabinet edge on the wall.

Next, you can take the cabinet away to take the next measurements. If any of the plumbing comes from the wall, measure the distance on the wall from where the cabinet starts to the pipes, then check the height from the floor and transfer those measurements onto the back of the cabinet.

For plumbing rising from the floor, there will possibly be a drain hole already in the cabinet floor, but it may or may not be in the right location, in which case you should again measure from the edge where the cabinet starts (on the floor) over to the pipe, and then the distance perpendicular to the back wall.

You can now transfer those measurements to the floor of the cabinet. Nothing needs to be drilled just yet.

Step 3 - Double-Checking the markings

Placing the cabinet back in its spot, use a small and long drill bit to explore where your markings will land you, and drill a small hole through the first marking and look to see if it lines up with the pipe behind it. If it doesn't, adjust your marking and try again.

Once you get it exactly or close enough, pull the cabinet away from the wall and use a hole saw slightly larger than the size of the pipe to enlarge the hole using the pilot hole as a guide. Proceed the same way for the remaining holes.

Step 4 - Attaching the Base

With this done, use a stud finder to locate the studs behind and on the wall side of the cabinet, and mark their location on the wall just above the cabinet height, so that the countertop hides them later on.

You can now place the cabinet in its rightful location screw it to two available studs and verify the location of the drain pipe and the two water lines for accuracy.

Depending on the accuracy of your measurements, this is where you should adjust the holes for the pipes to go through by trimming with a rotary tool or a jigsaw, in which case the cabinet should again be removed from the wall to avoid any risk of damaging the plumbing.

Now that everything lines up perfectly, secure the cabinet in place permanently this time, by screwing it to available studs with at least three or four wood screws #10 x 2-1/2 inch or longer, making sure that the cabinet is still level.

Step 5 - Installing the Sink

If your countertop is a molded type with a recessed bowl, you just need to put it on the base cabinet and secure it in place. If they're separate, you'll need to use the template to cut out the opening through the countertop and the holes for the water faucets.

Either way, the sink needs to be installed onto its cabinet, secured, and sealed with a bead of silicone.

This next step will require a few plumbing skills. The pipe connecting the sink drain to the ABS drain line can be installed (but always before the waterlines) to avoid accidental flooding. With that done, both waterlines can be hooked up with flexible hoses.

You can now test it to make sure that there are no leaks and also check that the water lines did not get mixed up.

Step 6 - Installing the Drawers and Doors

You can now install the drawers. Attach the handles to the cabinets by drilling holes at the appropriate spots. You can buy fancy handles for your cabinet to improve the style of the cabinet. Some cabinets will have holes already in place for the handles.

The doors should fit easily into their "Clip-On" mates or be screwed back into position. Test everything for their proper positioning and spacing, and adjust if necessary.