How to Install Kitchen Cabinets

by Samantha Rose

Install kitchen cabinets—base, wall and peninsula—using professional techniques. Hanging cabinets is easy and you'll save on your next kitchen remodel. The tricky part is scoping out the room to make sure everything fits and compensating for floors and walls that aren’t always square, level, or plumb. Follow these tips, and you’ll avoid those “gotcha” moments.

Step 1: Order the cabinets and assemble key tools and materials

Learning how to install kitchen cabinets may seem intimidating, but the techniques are quite simple. Think of it as screwing a series of boxes to the wall and to one another in the proper sequence. If your cabinet plan is correct, your main job is to find the best starting point and keep everything level. We will show you how to install kitchen cabinets and master these key steps. We’ll tell you how to lay out the cabinet positions ahead of time to avoid missteps. Then we’ll show you how to install the upper cabinets Last, we’ll show you how to install the base cabinets, so they’re perfectly aligned and ready to be measured for the new countertop. The entire how to install kitchen cabinets project typically takes less than a day. And depending on how large and elaborate your kitchen is, you’ll save at least $500 (and probably much more) in installation charges.

You only need a few basic tools to do a professional job. You’ll need an accurate 4-ft. level, a screw gun powerful enough to drive 2-1/2-in. screws and a couple of good screw clamps that open to at least 8 in. Buy a 1/8-in. combination drill/countersink bit for predrilling the screw holes. You’ll also need a block plane or belt sander for fine tuning the cuts to fit. A 1-lb. box of 2-1/2-in. screws and three bundles of shims will be enough for nearly any kitchen full of cabinets.

Make sure you have the right cabinets
The cabinets shown are called “face frame” cabinets, meaning they have a 3/4-in.- thick 1 ½” Wide frame surrounding the front of the cabinet box. “European” style (also called “frameless”) cabinets are simple boxes without the face frame, and they require a few special installation steps that we won’t cover in this article.

We won’t cover planning and ordering your cabinets here either. Just about any home center or lumberyard that sells factory- built cabinets will help you custom-design your kitchen cabinet layout. All the staff needs is a drawing of your existing kitchen floor plan complete with exact appliance locations and room dimensions. We highly recommend that you order at least two extra filler strips for backups in case of miscuts. Keep a copy of the layout, you’ll need it to guide your installation.

When your cabinets arrive, open up the boxes immediately and confirm that each cabinet matches the one on the plan, all the parts are included and there’s no damage. A single mistake can delay the entire project.

Step 2: Mark the cabinet height

Draw a level line on the wall 34-1/2 in. above the highest spot on the floor. Draw vertical lines to mark each cabinet location, label each cabinet’s position on the wall and find and mark the studs.

Find the highest spot on the floor

Most kitchen floors are very flat, especially in homes less than 40 years old. But it’s always best to confirm that by looking for the highest spot on the floor anywhere a cabinet will sit. You’ll measure up from that spot and draw a level line to define the top of all of the base cabinets.

Find that spot with a straight 8-ft.- long 2×4 (or shorter to fit between the end walls if needed) and a 4-ft. level. Rest the 2×4 with the level on top about 1 ft. away and parallel to the wall and shim the 2×4 until it’s level. Then mark the highest spot on the floor and repeat near any other walls that’ll have cabinets. Continue until you find the highest spot. If you have two high spots, rest the board on both and find the highest one. Measure up the wall behind that spot exactly 34-1/2 in. (standard cabinet height) and mark the wall at that point. Using that mark as a starting point, draw a level line along the walls wherever base cabinets are planned In older homes, very few kitchen floors are perfectly flat and level. We can make up for minor imperfections by shimming base cabinets up or cutting the toekick down. Shimming is easier than cutting, so the first step in laying out the cabinets is to find the high spots. 

We use a laser level and a tape measure to shoot elevations against walls that will receive base cabinets. Once we find the high spot, we measure up and make a mark to show where the top of the base cabinets will fall, which is usually 34½ inches off the high spot on the finished floor. From that mark, we snap a level line on the drywall around the room to mark the top of the base cabinets. 

We double-check the location of the dishwasher, range, and any other undercounter appliances to make sure we can adjust their height within the range of the built-in adjustable feet. If there’s a hump or drop of more than about ½ inch in one of these locations, we may split the difference. In that case, we would cut the cabinets down at the high spot and shim them up at the low spots. 

Step 3: Mark the cabinet positions

Draw a level line 19-1/2 in. above the lower cabinets and mark the upper cabinet positions. Screw a 1×2 ledger to the wall even with the level line.

The only tricky part about hanging upper cabinets is supporting them in exactly the right position while you screw them to the wall and one another. That’s a tough, awkward task, especially if you’re working alone. The ledger method simplifies this. It’s a fail-safe method, but you’ll have to accept a bit of patching and paint retouching to repair the screw holes left from the ledger.

Start by making a light pencil mark 19-1/2 in. up from the lower cabinets line (it’ll be 18 in. after the countertop is installed) and then mark the stud locations using the ones below as a guide. Next, transfer the cabinet positioning lines from below and screw a 1×2 ledger to the studs even with the layout lines. It’s best to prestart the cabinet screws before hoisting the cabinets up onto the ledger. You’ll often find that a cabinet, especially a narrow one, will have only one stud behind it. Don’t worry; the other cabinets will help support it too.

Start any corner cabinets first. Be exact with the first cabinet because it will define the locations of all the rest of the cabinets on that wall.

Start the screws and hoist the next cabinet into place, snugging its frame against the neighboring one, and screw it to the wall. Next, align the frames and clamp them together. You’ll probably have to back out the stud screws slightly in one or both cabinets to get the frames to line up perfectly. That’s fine—leave the screws backed out while you clamp, drill and screw the frames together.

One great installation trick it to screw the cabinet together where the hinge would cover it, as always make sure to drill pilot holes first to avoid risking splitting the frame.

Step 4: Measure from the top down for uppers

If the cabinet system includes a tall cabinet or a full-height panel, we use that to set the height of the wall cabinets. We will measure up from the high spot on the floor and snap a level line where the top of the tall cabinet will fall, then measure down the height of the wall cabinets and snap another line. These two lines establish the top and bottom of the wall cabinets. In a kitchen with a 96-inch-tall full-height cabinet, for example, our upper line will be 96 inches off the high spot. We’ll measure down 42 inches to locate the bottoms of most of the wall cabinets (less for shorter wall cabinets over the range and fridge). This leaves 19½ inches for a countertop and the code-required 18-inch backsplash, plus a little wiggle room.

Step 5: Base Cabinets 

We mark the base cabinet locations on the wall to make sure everything fits and properly aligns. If there is a sink cabinet that has to center on a window, we lay that out first; otherwise, we start at the corners and work toward the middle. We use filler strips in the middle of the run to make up for any spacing adjustments. We also use fillers at base and wall end cabinets to make up for irregularities and any slight out-of-plumb condition.

If the corners are out of square, or if either of the end walls is not plumb, we will need to adjust the location of the base cabinets. A corner that’s only slightly greater than 90 degrees usually means we can put the back of the corner cabinet up against one wall—usually the longer wall—and make up for the out-of-square condition at the back of the countertop on the short run of cabinets. If the corner angle is slightly less than 90 degrees—or if the end wall is leaning in at the top—we will still try to place the back of the cabinet against the long wall, but we’ll need to hold it in from the short wall enough to make sure the wall cabinets align with the base cabinets on the long wall and that the cabinet fronts on the short wall can be aligned without having to shave the drywall.

Test-fit the base cabinets

In most cases, the corner cabinets determine where the rest of the cabinets go. That’s especially true with lazy Susan corner cabinets, which have face frames facing two directions and have to meet adjoining cabinets perfectly. Our kitchen’s “blind-corner” cabinets are a bit more forgiving. Check your cabinet layout by “dry-fitting” all the base cabinets, starting with the corner ones, and setting all the cabinets in place as tightly together as possible. If the layout calls for filler strips, make sure to leave spaces for those, too. With the cabinets in place, check to make sure drawers and doors clear one another, appliance openings are the proper widths and sink bases center under windows above. Unless your cabinet plan is flawed, any adjustments you’ll need to make are just a matter of ripping filler strips narrower or using wider ones. Next, remove the shelves, drawers and doors and mark them and their matching cabinets with numbered masking tape to save time and confusion later. Then move the cabinets out of the room. Starting with the corner cabinets, carefully measure, draw and label each base cabinet and appliance location on the wall. Use a 4-ft. level and a pencil. The marks should reflect the width of the face frame, not the cabinet back. (The cabinet back is actually 1/2 in. narrower than the front, 1/4 in. on each side.) Use a stud finder or probe with nails to find and mark the stud locations just above the horizontal leveling line.

Position the first cabinet

Set the first cabinet 1/4 in. from the positioning line and shim the base until the top is even with the horizontal line and level from front to back. Drive 2-1/2-in. screws through the back into the wall studs to anchor it.

Position the corner cabinets 1/4 in. away from the vertical positioning lines. Shim the base until the cabinet top is even with the horizontal leveling line and then level and shim the cabinet front to back. If there’s a gap between the wall and the cabinet back (the wall isn’t exactly plumb or straight), slip in shims and run screws into the studs through the cabinet back about 1 in. down from the top. After all the base cabinets are set, score the shims with a utility knife and snap them off even with the cabinet top.

Position, level and shim the next cabinet and clamp it to the first cabinet (Photo 3). Run your fingers over the joint and you’ll be able to feel if it’s misaligned. Loosen each clamp one at a time and tweak the cabinet frames until they’re perfectly flush, then retighten the clamp. Be fussy! Sometimes you’ll have to loosen the screws holding the previous cabinet against the wall and pull it away slightly to get the frames aligned. When you’re satisfied, drill pilot holes through the frames 1 to 2 in. from the top and bottom of the cabinet interior.

Make sure you’re drilling straight. The most common mistake is to run the bit through the front of the cabinet frame! With the face-frame screws in place, remove the clamps and screw the cabinet to the wall. Repeat the same process for each consecutive cabinet.

Make plumbing and electrical cutouts

Lay out plumbing and electrical openings on the cabinet back, using the layout lines on the wall as reference points. Then drill and/or saw out the openings.

You’ll probably have to cut openings for the drain and water supply lines and for outlets Lay out the openings by measuring from the layout lines at the top and side, and then transfer those numbers to the back of the cabinet. To avoid confusion, do the layout work with the cabinet near its position and in the right orientation. Drill holes for water supply lines and starter holes for square openings with a 1-in. spade bit. Stop drilling when the tip just penetrates the back, and finish the holes from the inside of the cabinet to prevent splintering the cabinet interior. Cut square openings with a jigsaw. If your drain line projects from the wall at an angle, simply cut a rectangular hole around it.

Step 6: Minimize drywall repairs

Before the drywall goes up, we mark the locations of any wiring rough-ins for under-cabinet lighting. If these stub-outs are too low, it could mean having to patch the drywall later. Instead of trying to locate these precisely, we mark them an inch or two high. That way, when it comes time to hang the wall cabinets, we can cut a small slot in the drywall so we can slide the wire down until it perfectly aligns with the hole in the cabinet mounting rail.

Step 7: Hang the uppers first

We always hang wall cabinets first because we can get our step ladders under the work, which makes it easier to lift and hold cabinets in place during alignment and fastening. Not having to reach over the base cabinets also means there is less chance we will scratch the finish or otherwise damage them.

Step 8: Start plumb and stay that way

Cabinets are always installed level and plumb, so when walls are out-of-plumb, there will be gaps. Accurate layout allows space to fasten a filler strip that has been scribed to match irregularities in the wall to the edge of the cabinet facing. This also works where the backs of finished end panels meet out-of-plumb walls.

Step 9: Finish Line

Finish off the cabinets by cutting, fitting and nailing the toe-kick boards to the bases. They’ll be 4 1/2 in. wide, but on irregular floors, you may need to rip them narrower to get them to fit. If you have bad gaps between the floor and the toe-kicks, add base shoe contoured to fit the floor. Wherever cabinets have finished ends, run the toe-kick boards 1/4 in. past the cabinet for a nice appearance. Finish up by slipping the drawers into their slides and reattaching the doors. Adjust the hinges until the doors line up perfectly and move on to installing the door and drawer pulls.

Please reach out to one of our kitchen designers for a free kitchen design and help with all your kitchen questions. Call us at 800-788-7575 or email your design to sales@rtawoodcbainets.com