How to Install Bottom Mount Drawer Slides

Bottom mount drawer slides take up less space than traditional side-mount drawer slides, making them an attractive option to get as much drawer space as possible. They can be tricky to install, though, and no one wants a wobbly or ill-fitting drawer in their new cabinets. Read this article for foolproof instructions on installing bottom mount drawer slides.

How to Install Bottom Mount Drawer Slides

Bottom mount drawer slides come in two pieces. One attaches to the drawer, and the other to the frame of the cabinet.

1. Determine how many slides you need. Instead of two slides per drawer, as in a side mount set up, just one undermount drawer slide is required for installation, saving you time and money. Drawer slides come with a rating of how much weight they can support – usually 25 pounds. If you have an extra-wide drawer, or one that will contain more than 25 pounds of kitchen supplies, consider installing two slides instead of one.
2. Check the thickness of your drawer bottom. If it’s half an inch or more thick, you’re good to go. If not, you’ll need to grab some spacers to make sure the mounting screws don’t break through the drawer bottom.
3. Check your clearance. To ensure adequate room for the slides to be installed, you need 5/16 of an inch between the bottom of the drawer and the opening. This gives you enough space for the slide mount (typically ⅜ of an inch) to slide easily past the cabinet’s face frame.
4. Inset or overlay? Inset drawers are designed to be flush with the surface of the cabinet when closed, giving a streamlined look. Overlay drawers have a veneer that rests against the cabinet face front when the drawer is closed. If you have overlay drawers, you’ll need to notch the drawer box so the slides can be attached – see the section below.
5. Attach the slide to the bottom of the drawer. Make a mark with pencil at the front and back of the drawer, exactly in the middle of the drawer’s width. Align the drawer slide so that it is centered on these marks, and flush with the front of the drawer. The slide mount should have come with appropriate screws, although you may need to add a spacer. Attach the first screw, and check the alignment of the slide before inserting the second screw.
6. Attach the cabinet mount. Mark the exact center of the drawer opening on the inside of the face mount. Align the cabinet mount so it is centered over the mark, flush with the opening, and use one screw to attach it. Use a second screw and a mounting bracket to hold the back of the cabinet mount to the rear of the cabinet or the dust frame.
7. Insert the drawer. Line up the bottom of the drawer slide with the cabinet mount, and ease it on. The drawer should close fully and easily. If you notice rocking or sticking, consult my troubleshooting guide below.

Troubleshooting Bottom Mount Drawer Slides

No matter how carefully you measured, cut, and screwed, problems can sometimes occur. Check out these common issues to figure out what is causing your problem and how to fix it.

Side to Side Rocking 

Side to side rocking is a common complaint about base mount drawer slides. It usually means that the drawer was too wide, or the contents too heavy, to be supported by a single slide. However, sometimes it’s just an issue of a wobbly mount. You have two options to fix it.

1. Remove and reinstall. Divide the width of the drawer into thirds, and reinstall the drawer slide a third of the way in from one side. Attach another drawer slide on the other side, one-third of the way in. This will give your drawer the balance and stability it needs.
2. Use drawer glides. Adhesive or nail-in drawer glides are a nifty little tool that adds support to the bottom of your drawer without requiring installation of a second slide. They are good for stabilizing wide drawers that don’t hold heavy weight.

Attach the drawer glides to the inside of the drawer opening on the bottom corners, where the drawer edges will pass.

Learn more about how to measure drawer pulls while you’re at it.

Drawers That Won’t Close

It’s frustrating to encounter a door that won’t close. When shoving it harder doesn’t work, take a deep breath and check out the possible causes (and solutions!) below.

• Interference. The bottom mount shelf slide can easily get blocked from operation by the presence of objects in the cabinet or drawer immediately above it. Try clearing out the items from the drawer or cabinet below, and see if that fixes the problem. If they close but it’s too aggressive, you might want to opt for the best soft close drawer slides.
• Misalignment. If you’ve measured perfectly and squared the front and back of each slide to its respective mount, the drawer bottom slide should glide easily along the mount. Even a tiny mismatch in the angle of the slides can prevent the drawer bottom from sliding all the way into the opening. Check your measurements – you may need to remove one or both parts of the slide and adjust the installation for a better fit.
• Defective slides. To function properly, door slides must be in good condition. The channels should be straight, allowing the rollers to easily pass through them.

If any part of the slide has warped, twisted, or bent, it may block the path of the rollers and leave your drawer sticking out. If this happens, it’s best to remove the defective or damaged drawer slide and replace it with new, undamaged hardware.

Notching the Drawer Box on Overlay Drawers

You can’t attach a drawer slide directly to the overlay of a drawer.. Instead, you need to notch the bottom of the drawer box so the slide can sit flush with the bottom of the drawer. Here’s how:

1. Know what you’re looking at. The drawer box is where your kitchen implements will sit. The overlay is a decorative piece that attaches to the front of the door box and rests against the cabinet’s front face when the drawer is closed.
2. Measure and mark. Once you’ve measured and marked where the center of your drawer slide will be, make an additional two marks in pencil. Mark ⅛ an inch away on each side. This is your cut line.
3. Cut and chisel the notch. Use a handsaw such as a coping saw to cut along your cut lines, stopping when the bottom of the drawer box front is level with the drawer box bottom. Use a chisel and a hammer to remove the waste between the two cut lines, and smooth with sanding paper.
4. Check the back. Repeat the process on the back of the drawer box, if necessary. Install the drawer slides in the notch, flush with the drawer box bottom.

Why Should I Choose Bottom Mount Drawer Slides?

There are a few reasons to choose bottom mount drawer slides — they give you more space and reduce the cost and effort of your drawer slide installation project.

• More space. Bottom mount drawer slides allow you to have wider drawer boxes than side-mount drawer slides, giving you more storage space in the drawer itself. As an example, think about your bedside dresser. Dress drawer slides that side mount reduce the amount of space you have by quite a bit, and there usually isn’t much room to begin with.
• Reduced cost. Instead of installing two drawer slides on every drawer, you can usually get away with just one, effectively halving your material costs for drawer installation.
• Less effort. Side mount drawers must be perfectly aligned with each other in order to work. Bottom drawer slides are much more forgiving because they rest on the cabinet face front. They are therefore easier to install.

Conclusion

Installing bottom mount drawer slides requires careful measuring and a good amount of patience. However, they can be effectively installed by DIYers who are prepared to troubleshoot. Bottom mount drawer slides have several advantages over side-mount drawer slides.