How to Make a 12' Ladder

Clamp the two 12 foot pieces of wood together, make sure the ends and sides are flush. Use a clamp every 3 feet to ensure the wood pieces remain lined up correctly. Set the wood on a work table.

Sit the wood on its side. Mark a spot 8 inches from the top of the wood. Mark a spot 8 inches from the bottom of the wood. These are the spots for the top and bottom steps, or rungs. Measure and mark 2 1/2 inches toward the center of the wood from the marks you just made. These are the marks that you will use for the step notches.

Stretch the tape measure out to measure from the bottom-most mark. Mark the wood every 16 inches, for the step positions. Measure and mark 1 1/4 inches from each of the marks you just made, for the width of the steps.

Place the square ( or ruler) on the step marks, and mark them 1 1/8 inches inwards or deep. This is the amount to be notched with your chisel.

Adjust your circular saw to a depth of 1 1/8 inches. Cut the notches along the pencil marks you made earlier. Place another notch in the middle of the two outer cuts of each notch. This will help to chisel it out later.

Break the remaining wood out of the notches with your hammer and chisel. Scrape the edges with the chisel to clear any small bits of wood. Make sure the notches are square and free of debris.

Cut the 2-by 3-inch by 8 feet pieces of wood into 19-inch lengths. These will be the steps. Drill two holes into the side edges of the steps with the countersink drill bit.

Unclamp the 12 foot sections of wood. Apply a coating of wood glue to the first and last notches. Place a 19-inch piece of wood into the top notch. Tap the wood into the notch with your hammer if it sticks. Repeat for the last step notch. Screw two deck screws into the each side of the the ladder frame and into the steps, through the countersink holes. Repeat this process for the remaining steps (glue, step, screws).

Sand any rough edges with sandpaper. Stain the ladder with two coats of urethane or heavy-use paint.