I recently wrapped up the construction on my new work surface / workbench in the garage at our new home. The final measurements are 12 feet long, 2 feet deep, with a slightly larger angled corner work area. There was an existing metal cabinet that I wanted to match the bench height to, so the entire work surface is a very comfortable 42" height - which just happens to match the "belly-button height" guideline for building benches, too! The top is a dual-layer construction with a plywood base for stability and a melamine-wrapped OSB work surface for easy cleanup and chemical/water resistance.

Parts list:
4'x8' sheet of 1/2 inch plywood - I had Lowes cut it down to 4x4, 2x4, and 2x4
4'x8' sheet of 3/4 inch OSB (melamine-wrapped) - I had Lowes cut it down to 4x4, 2x4, and 2x4
Multiple 8 foot 2x4s - Cut to various lengths (I think I used a total of 8 or 10 boards)
Small box of 3-inch deck screws
Large box of 2.5-inch deck screws
Small box of 1.25-inch exterior screws

Tools Used:
Tape Measure
Level
Square
Screw Gun
Drill
Jig Saw

Time to Complete:
Roughly 4 hours. It took me a while because I was very careful about leveling, measuring, cutting, and pre-drilling on this project.

Cost to Complete:
Approximately $100 in materials.

*It should be noted that I pre-drilled EVERY hole for this project so that I would not split the 2x4s, the wall studs, or the work surface.*

Step 1: Planning

I did a quick rendering in Google Sketchup to figure out the measurements I wanted for the work surface, and also to get a general idea of how I wanted to brace the underside for strength and stability. The final measurements are not exact to my Sketchup rendering because I chose to do a dual-layer work surface, but the 3d drawing only shows a 1/2" plywood surface.

*It should be noted that I pre-drilled EVERY hole for this project so that I would not split the 2x4s, the wall studs, or the work surface.*

Step 2: Constructing the Base

I started by installing 12 feet of 2x4 to the wall studs in one direction, and 4 feet of 2x4 in the other. I secured these using 3 inch long decking screws. This creates a nice stable platform to build the frame from. I was working alone, so it was a difficult task to keep such long runs of 2x4 level, but it came out quite good.

After installing the "headers" to the wall studs, I installed the 2x4 cross members that connect the front face to the rear header. I toe-nailed these pieces using 2.5 inch deck screws. After making sure everything was square and level, I installed leg extensions to the front of the form. I did not anchor these to the floor, but might do that in the future for added piece-of-mind.

Once the square parts of the frame are completed, it is time to: triangulate, triangulate, triangulate! I installed a lot of mitered 2x4s to add stability and distribute the weight across the various parts of the bench. I varied the length of these so that the toe-nailed screws would not come into contact inside the frame. I can tell you that the bench supports all 215 lbs of my weight at every point, so it should do just fine for normal uses.

*It should be noted that I pre-drilled EVERY hole for this project so that I would not split the 2x4s, the wall studs, or the work surface.*

Step 3: Securing the Work Surface

I chose to use a dual layer work surface for my workbench for two reasons:
1. The bottom layer of plywood gives the bench some "grain" for stability, and also a level surface to mount a top on.
2. The top layer of melamine-wrapped OSB is easy to clean, and can be replaced later if it gets too damaged.

The first thing I did was lay out the 4'x4' piece of plywood for the corner of the workbench and mark it to cut the angled portion. I just used a jig saw to do this since it was handy. Once you have cut the plywood, secure it to the assembled frame. I used 1.25 inch exterior screws to attache the plywood to the frame. Because the plywood is not going to be seen or used for working on, I secured it along all the edges as well as at each triangulated joint. I wanted to make certain that it was securely fastened, and as level as possible.

Once the plywood was in place, I repeated the angled cut on the OSB, and began attaching the three pieces of using four 2.5 inch deck screws in each piece. The OSB is so heavy and thick that I was not overly worried about securing it, other than to make sure it would not move. Additionally, since I want to be able to easily remove the OSB later if it becomes damaged, the fewer screws there are the easier that process will be.

*It should be noted that I pre-drilled EVERY hole for this project so that I would not split the 2x4s, the wall studs, or the work surface.*