This post has been mostly done for a few months. I guess I started it and then forgot about it. I also kind of failed at taking pictures before or during, so all you get is the after shot. Sorry.
The cupboard above the ovens is a hazard. Whenever I want something out of there, I have to either take a bunch of other things out as well or risk having cookie sheets and roasting pans come crashing down on me. It's a large, deep, wonderful cupboard, but it only has one shelf. Since most of the things we put in there are relatively flat, it means we get large piles of pots and pans, making it difficult to get to the thing you want.
For probably at least a couple of years, every now and then I'd say to Zach, "we should get some sort of extra shelf to put in the middle of this cupboard." Zach would agree, and then we'd both forget about it for awhile. Then, when we got our bathroom cabinet installed, it came with extra pegs for holding the shelves. Since this is the same type of cabinet as in our kitchen, the pegs were the right fit there. It still took several months, but I finally got around to building an extra shelf for the over-the-oven cabinet.
First, I took everything out of the cabinet and measured. It was a little tricky because there's some sort of box (probably electrical stuff) in the back of the cabinet that I'd have to make a cut-out for. Then I went to the garage to see if I had any extra boards that were big enough to use. I did have a piece of MDF that was big enough, but MDF is super heavy. Not only did I not want to lift that heavy piece up awkwardly high over my head to install as a shelf, I wasn't confident in the little pegs' ability to support that much weight. So I went to Home Depot in search of a light-weight board.
I was planning to get plywood, but first I checked out the hobby wood section, just in case, and found exactly what I needed -- 3/4" pine, 2' x 4'. I took it home and cut it to size. Before finishing it, I did a test fit to make sure I had measured right, and it fit perfectly! I had also gotten a light stain with the idea of attempting to match the inside of the cabinet. Well, I put the stain on the wood with a rag, and it totally did not match at all. However, it won't be very visible, so I'm not too concerned. Since the stain was already quite a bit darker than the interior of the cabinet, I only did one coat of stain. Then I did lots of coats of spray polyurethane.
And now, every time I open that previously horrible cabinet, I smile :-)