I am looking to install some custom shelving for a 4’x4’ closet. I would like the shelves to be in an L shaped configuration against the rear and right walls of the closet. The back portion of the shelves will be 18” deep, and the right will be 12” deep. Every part of the shelf touching the walls will be supported by 1x2’s screwed into the studs. For the shelf itself, I’m using 3/4” birch plywood.

Because there is not a way to cut the shelves as a single piece without wasting material, I’m planning to cut each shelf into a 18”x3’ piece and a 12”x4’ piece. The 18”x3’ piece will only be supported from the walls on two sides, so I will need a crossmember. This is where I am unsure how to proceed.

I have 2 studs along the side walls opposite each other about 9” off of the rear wall. If I want the crossmember to be driven into these studs, I could use pocket screws to secure a 2x2 across the width of the closet. This means the front half of the 18” shelf will not be supported. If the 1x2 alone is strong enough, I could move the 2x2 crossmember all the way to the front.

Should I secure the crossmember with one or two pocket holes on each side? Should I use a 2x2 or a 2x4? Should the pocket holes be facing up or down? Should the crossmember span the middle of the shelf so it can go into the studs, or at the front? Are pocket screws the best solution here?

  • How much weight do you expect to put on the shelves?
    – crip659
    May 29, 2022 at 16:15
  • 1
    A common solution is to put a post in the inside corner of the L For many things, it does not get in the way sufficiently to be a problem, and it provides excellent support. A 2x2 will do for that for most reasonable values of shelf loading.
    – Ecnerwal
    May 29, 2022 at 16:18
  • I’m planning to put 2 plastic storage bins against the rear wall on each shelf. I would expect 150 lbs as the absolute max. Most likely well under 100 lbs. May 29, 2022 at 16:33

1 Answer 1


The weight on the shelves would have to be very oddly distributed for it to matter whether you place the cross member at the front or the middle of the shelf, and if you are supporting 150 lbs, best to screw into the studs.

Pocket screws seems fine. I don't know that the direction matters very much, but I would probably face them down so they are accessible even with the shelf installed (unless the shelf is low, in which case up would be easier).

Two screws seems sturdier, but might be a challenge with a 2x2. Honestly, this thing seems like it's going to be overbuilt (not a criticism) no matter what, so probably not a huge deal either way.

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