Initially, I thought I could assemble the entire shelf in the garage, and that my wife and I could move it into the study. As my wife is happy to tease me, what in the world was I thinking? Weight-wise, it wouldn't have been a problem. Size-wise, it's theoretically possible, but totally impractical. We'd have dinged the frame of every door and cased opening along the path. So, I did the final assembly in the study.

Here's the finished back panel with the shelf alignment dowels in place.

I did one last dry fit in the garage to make sure the shelves would slide over the dowels, and I also checked to see if I could fit the sides between the attached shelves. In most cases, the shelves had just enough "give" to make it work. (If you recall from an earlier post, I had trimmed the dowels in the sides to short stubs.) In two cases, the shelf offsets from the panel were too short to allow any flex.

I placed all the shelves face-down on the study's floor, then glued and clamped the sides between the short-offset shelves. After the glue dried, my wife helped me place the back panel onto the shelves. With that done, it was a simple matter to drive eight 2" long, #14 screws through the back panel into each shelf. (I had drilled and countersunk the screw holes earlier.) I staggered the screws vertically to try to counteract sagging forces on the front edges of the shelves.

Here is the unit, ready to install. (The remaining sides are not in place yet—I decided to wait until the shelf was on the wall so I could spread glue on horizontal surfaces.)

To install the shelf, I placed the wall cleats and guide in position and drove two 3-inch x 1/4" lag screws through each cleat.

Then I removed the temporary guide boards, and we were ready to install.

Getting the assembled shelf over the cleats and onto the wall was a bit of a struggle for two people, but we managed to do it. (Three people would have been better two to lift, and one to direct the positioning.) After that, all that remained was gluing and clamping the remaining sides.

At long last, the shelf was finished.

As a reminder, here's the pre-construction SketchUp rendering.

And here's the real thing.

Unfortunately, despite all my care with the cleats, the shelf isn't perfectly level. I'm not sure what went wrong. Maybe I did not accurately level the cleats, or maybe the shelf cleats aren't mating perfectly with the wall cleats. If it bothers us enough, we can remove the shelf, make adjustments, and re-install, but we'll hold off on that for now.

Thanks to anyone who has read along. Happy woodworking!