DIY Base Cabinet Filler

Measure the height of the gap from the bottom of the countertop to the top of the toe kick. The toe kick is the 4- to 6-inch-high indentation at the bottom of the cabinet. Transfer the measurement to the 1-by-10 lumber.

Raise the table saw blade to 1 inch. Place the 1-by-10 on the table saw against the miter gauge. Align the cut mark with the blade. Turn the saw on and feed the lumber through the blade to cut it off on the mark. Turn the saw off and remove the miter gauge from the saw.

Measure the gap between the base cabinet and the wall. Set the table saw fence to the gap width measured. Turn the saw on and feed the cutoff filler piece through the blade with one edge against the fence. Use push sticks to push the lumber through the blade as the end of the piece nears the blade.

Stand the filler piece on the floor in the gap between the cabinet and the wall, with the face of the filler piece flush with the face of the cabinet. Mark the wall using the back side of the filler piece as a guide. Remove the filler piece.

Hold the 2-by-4 against the wall with the front edge against the line. Drill two holes through the 2-by-4 into the wall, one near the top and one near the bottom. Install a drywall anchor in each hole in the wall, unless the holes reveal a stud. Screw the 2-by-4 to the wall with 3-inch wood screws.

Hold the filler piece in the gap against the 2-by-4, flush with the base cabinet with the top against the bottom of the countertop. Drill pilot holes through the base cabinet side into the filler piece using the countersinking drill bit. Drill one hole 1 inch from the top and another 1 inch from bottom. Drill a third hole in the middle.

Screw the base cabinet to the filler piece using wood screws. Drill three, 1/16-inch pilot holes through the filler piece into the 2-by-4. Nail the filler piece to the 2-by-4 with finish nails. Place the point of the nail set against the head of a finish nail. Tap the nail set with the hammer to set the nails below the surface of the wood. Fill the nail holes with color-matched wood putty.