dadiOH wrote:
1. Split the new piece

2. Screw/glue a piece of 1x2 or 1x3 along the split on the bottom side of
one piece so it overhangs the bottom by 3/4" or so.

3. Put in the piece from #3

4. Put in the other split piece. The batten will support it along the
split. Screw to it if you like.

Yeah, I like this idea. I'll just stain the plywood and save myself the
trouble of laying tiles.

Thanks!