How Are Kitchen Cabinets Attached? | Solid Fix Guide

Wall and base boxes don’t stay put by luck. They rely on a simple recipe: find solid framing, hold every box in line, and drive the right fasteners in the right spots. Do that, and runs stay square and doors swing true.

This guide walks you through the hardware, order of work, and checks that keep things tight. The steps here match what pros do and what trusted trade guides recommend.

How Kitchen Cabinets Are Fixed To Walls Safely

Most wall units hang off their built-in rails. Those rails sit near the top and bottom of the back panel. The installer locates studs, holds the box to layout lines, slips in shims where the wall waves, and drives screws through the rail into framing. A temporary ledger under the line takes the weight while you work, then comes off once the run is locked.

Base units anchor through back rails as well. Level the first box, shim the low spots, clamp faces so seams vanish, then drive screws into studs. Join neighbors through the face frames or side panels, recheck reveal lines, and then seat all screws.

Core Hardware And What Each Piece Does

You only need a few fastener types. Pick lengths that bite solid wood and heads that draw the box tight without crushing the back.

Fastener	Typical Length	Primary Use
Washer-head cabinet screw (#8)	2–2½ in.	Through hanging rails into studs; broad head spreads load.
#10 structural screw	2½–3 in.	Extra bite on uneven walls or heavy units; drives cleanly.
Face-frame screw	1¼–1½ in.	Clamps neighboring frames; predrill to avoid splits.

Studs, Lines, And A Ledger

Snap level lines for tops and bottoms of wall units. Set a straight 1×3 cleat just under the line so every box can rest while you fasten. Drive temporary screws into every other stud. Lift the first wall box onto the cleat, check level and plumb, shim, and fasten through the rail. Work out from a corner or the range center line for even reveals.

Many pro tutorials teach this ledger method because it saves your back and keeps the whole run aligned from the start. A widely read step list shows the same order: remove doors and shelves, set the cleat, rest the box, shim, and screw through studs. You can see that process in the This Old House cabinet install shows the cleat and sequence.

What Actually Holds The Load

The back rails and the studs do the heavy lifting. Each wall box should hit at least two studs. Wider units often catch three. Use two screws into each stud rail zone on wall boxes and one to two per stud on base units, then add frame-to-frame screws between neighbors.

Manufacturers say to avoid brittle drywall screws. They snap under shear and the bugle heads chew through thin cabinet backs. A current installation booklet from a national maker calls for cabinet-rated screws through the rails, light clamping pressure between boxes, and shimming before final torque. You can read those notes in the Legacy installation guide, which also flags drywall screws as a poor choice.

Face-Frame And Frameless Differences

Face-frame lines get pulled together through the stiles. Clamp the faces, predrill, and drive a trim-head or a specialty frame screw. Frameless boxes join through the sides using confirmat or system screws into predrilled holes. In both cases, the wall fasteners carry the weight; the joiners just keep faces even.

Choosing Screw Length And Head Style

Look for washer-head or low-profile cabinet screws in #8 or #10. Those heads act like built-in washers and draw the rail tight without burying into the back. Length depends on the stack: cabinet back plus drywall plus the bite into wood. Many installers reach for 2½ in. on walls and 2 in. on bases. Heavier pieces or wavy walls may need 3 in. structural screws to grab deeper.

Many run from 1¼ in. up to 3⅛ in. with a T-15 drive and washer heads that spread load.

Stud Spacing, Hits, And Screw Count

Studs are usually 16 in. on center. Old houses may run at 24 in. or drift off a bit. Map them all with a stud finder, a rare earth magnet, or test holes behind a later filler. You want each box to grab every stud it crosses. That keeps doors from drifting and stops long runs from bowing.

Cabinet Width	Stud Hits To Aim For	Screws Per Stud
12–18 in.	2	2 at top rail
24–30 in.	2–3	2 at top, 1–2 at lower rail
33–36 in.	3	2 at top, 2 at lower rail

Order Of Work That Keeps Things Straight

1) Prep The Room

Strip the wall to solid paint. Mark stud centers with painter’s tape. Strike level lines for the bottoms of wall units and the tops of bases. Dry fit fillers and panels so gaps near corners are finished cleanly.

2) Start With Wall Units

Set the ledger under your line. Pull doors, drawers, and shelves to drop weight. Hang the first wall box at a corner or over range center line. Shim to the line, then set two screws into the first stud through the upper rail. Add a screw at the next stud. Check plumb, then add lower rail screws.

3) Join Neighbors Before Tightening

Clamp faces so they sit flush. Predrill through the frame stile or side panel, and add the joiner screws. Sight across the faces. Only after seams look clean do you snug the rail screws fully.

4) Move To Base Units

Find the high spot in the floor with a straightedge. Set the first base box there. Shim under the sides and back rail as needed. Anchor through the rear rail into studs, and tie boxes to each other through frames or sides. Leave room for appliance clearances; scribe fillers last.

Fastening Into Tough Wall Types

Old Plaster And Lath

Studs can wander and lath can crush. Pre-drill pilots through plaster to reduce cracks. Use longer screws so the bite in wood is solid. Shim behind rails at low spots so the box stays square.

Masonry Backing

Where studs are missing, set a continuous ledger into anchors along your line, then fasten boxes to that ledger. Tapcon-style anchors or shield anchors handle the ledger; the cabinet screws then drive into the ledger just like a stud.

Metal Studs

Use fine-thread screws through the rails, add wood blocking where runs carry stone tops, and watch for flex. A strip of plywood behind the rail spreads the load across more screws.

Why Rail Placement Matters

Hitting the upper rail first locks the line. That keeps door gaps true and sets the reference for the lower rail. On deep wall boxes or units with heavy doors, that upper row is the main anchor. The lower rail then keeps the box from rocking and adds shear strength.

Common Mistakes And Easy Fixes

Missing Studs

Screws that only catch drywall give a false sense of bite. If a screw spins, back it out, slide the box off the ledger, and shift to the nearest stud. Patch the stray hole later.

Over-Driven Screws

Crushed backs open the door to sag. Stop when the head sits snug to the rail. If a head sinks, back it out, add a washer-head screw next to it, and leave the crushed hole empty.

Skipping Shims

Gaps behind the rail pull boxes out of square. Add shims at low spots, trim them flush after the run is tight, and save the offcuts for base toe-kick shims.

Hardware That Makes The Job Smoother

Cabinet-rated screws with washer heads and a star drive are worth the small upcharge. Coated versions resist corrosion around sinks and dishwashers. Many makers show size ranges and head styles on their product pages, which helps you match length to wall build and to the bite you want.

Clamp Types

Use deep-throat F-style clamps on face frames and padded clamps on fillers. A soft block protects the finish while you pull seams tight.

Quick Reference Mounting Plan

Target Measurements And Steps

Use this cheat sheet as you work through a run. It pairs the sequence with targets that keep things plumb and true.

Step	Target	Tip
Layout	Dead-level lines	Snap lines at backsplash and toe heights.
Ledger	Cleat under wall line	Screw into every other stud.
First Box	Plumb on both edges	Shim behind rails, not the center.
Fasten	Two screws per stud	Upper rail first, then lower.
Join	Flush faces	Clamp, predrill, then drive.
Bases	Level across run	Start at the floor high spot.

Care After Mounting

Rehang doors and drawers, then tune hinges so reveals match. Add bumpers and adjust soft-close slides so drawers shut without rebound. Wipe rails and backs to remove dust before setting tops.

Proof Points From Trade Sources

The ledger method, the join-then-fasten order, and the use of cabinet-rated screws match the steps in the This Old House guide and the maker notes in the Legacy booklet linked above.