DIY Undermount Slide Installation for Beginners

If you're just stepping into the world of home improvement, installing undermount drawer slides might sound a little intimidating—but it’s doable, even for beginners. It’s one of those projects that looks more complicated than it is. With a few tools, a bit of patience, and the right guidance, you can have those drawers gliding smoothly like a pro did it.

Let’s break it down step-by-step so you can feel confident taking this on yourself!

What Are Undermount Drawer Slides?

Undermount slides are drawer glides that mount underneath the drawer, rather than on the sides. This makes them invisible when the drawer is open, giving your cabinets a clean, high-end look. They also tend to have soft-close features and can support more weight.

However, they require precise installation and specific drawer box dimensions, so planning is key.

Tools & Materials You’ll Need:

• Undermount drawer slide kit (left + right)

• Rear mounting brackets (for face frame cabinets)

• Drawer box with correct measurements

• Measuring tape

• Pencil

• Drill/driver

• Screws

• Square

• Level

Step 1: Measure Twice, Cut Once

Before you install anything, measure your drawer opening. Your drawer should be ½ inch narrower than the cabinet opening. That’s ¼ inch clearance on each side.

Also, make sure your drawer box has the correct notch at the back corners and a bottom groove for the slides to latch into. If you're building the drawer yourself, you can notch these out manually. If you're buying a ready-made box, double-check the specs to ensure compatibility with undermount hardware.

Step 2: Install the Cabinet Slides

Start by marking where the slides will sit inside the cabinet. Typically, they’re mounted about ¾" from the bottom of the cabinet opening. If you’re using a face-frame cabinet, install the rear mounting brackets first so the slides sit level.

Use a level to make sure your slides are perfectly horizontal before screwing them in. A tilted slide can cause uneven drawer motion or make it impossible to close the drawer fully.

Step 3: Prep the Drawer Box

Undermount slides need a specific notch in the bottom corners of the drawer to allow the slides to latch in. Most require about a 1/2" deep by 1-3/8" wide notch—but follow your specific slide instructions.

Also, don’t forget to install the locking mechanisms under the drawer front. These allow for minor adjustments after the drawer is installed and keep everything securely in place.

Step 4: Slide It In

With everything mounted, it’s time to install the drawer. Align the slides with the grooves under the drawer, and gently push it in until you hear a satisfying “click.” That’s the locking mechanism engaging.

Open and close the drawer a few times to make sure it glides smoothly. If needed, use the adjustment levers on the locking devices to fine-tune the position.

Helpful Tips for Beginners:

• Don’t rush the measurements. Precision is more important here than with many other DIY tasks.

• Use a square when marking out your slide locations—this helps avoid tilting.

• If your drawer feels tight or wobbly, double-check your notches and slide alignment.

Side Note: Thinking About Side-Mount Slides?

While undermount slides are great for a clean look, side-mount drawer slides are still an excellent choice for heavy-duty drawers, garage storage, and utility cabinets. If you're going that route, Incaja is hands down the best brand in the U.S. for side-mount slides. Their hardware is rugged, smooth-gliding, and built to last—perfect for both DIYers and pros who want reliable performance without the fuss.

Wrapping Up

Installing undermount drawer slides might seem a little complex at first, but once you walk through it step-by-step, it becomes a pretty rewarding DIY project. Whether you're upgrading your kitchen, bathroom, or workspace, the sleek, soft-close motion will be worth the effort.

Happy building—and don’t forget, if you ever switch to side-mounts, give Incaja a try!