Leveling a corner base cabinet involves adjusting its height and ensuring its top surface is perfectly horizontal in both directions (side-to-side and front-to-back) and that it sits plumb against the walls. The primary method for adjusting height is typically by using shims under the base or legs, often combined with securing the back of the cabinet to a ledger board on the wall.
General Leveling Principles
Before securing, you position the corner cabinet and begin the leveling process.
- Rough Positioning: Place the corner cabinet in its intended location.
- Identify Low Spots: Use a level placed across the top edges (side-to-side and front-to-back) and along the sides (for plumb) to find areas that are too low or where the cabinet doesn't meet the wall or floor correctly.
- Shim and Adjust: Insert shims (thin tapered pieces of wood or plastic) under the base or legs of the cabinet at the low points. Adjust the shims until the bubble on your level is centered in both directions on the top surface.
- Check for Plumb: Ensure the cabinet sides are vertical using the level.
Leveling the Back Using a 1x4 Ledger
A common technique, often used in conjunction with shimming the front or sides, involves securing the back of the cabinet to a pre-leveled 1x4 piece of lumber (a ledger board) attached to the wall. This helps establish a consistent height at the back and provides a strong anchoring point.
According to the provided reference, a method for leveling the back involves using a 1x4:
- Bring it up to the top of the 1 by 4: This implies a 1x4 board is already fixed to the wall at the desired finished cabinet height. You lift or adjust the back of the cabinet until its top edge or securing point aligns with the top of this ledger board.
- Screw through the back of the cabinet into the 1 by 4: Once the back of the cabinet is at the correct height relative to the 1x4, screws are driven from the inside back of the cabinet directly into the ledger board, securing the cabinet firmly to the wall at the proper level. The reference states, "Pull your cabinet out. Bring. It up to the top of the 1 by 4 and screw through the back of the cabinet into the 1 by 4."
This method ensures the back of the cabinet is supported and held at a consistent level, which is crucial when installing multiple cabinets along a wall.
Final Checks and Securing
After using shims and/or the 1x4 ledger method to achieve level and plumb, perform final checks:
- Verify the top surface is level side-to-side and front-to-back.
- Ensure the cabinet is plumb against the wall.
- Check that the cabinet front is square and not twisted.
- Secure the cabinet by screwing it to the wall studs (often through the 1x4 ledger) and to any adjacent cabinets. Trim or break off excess shim material.
Proper leveling ensures cabinet doors hang correctly, drawers operate smoothly, and the countertop will sit flat without stress points.
