How do you make a vertical slab in Minecraft on Xbox?

Solution 1:

Slabs can only be placed horizontally. They can be placed either in the "bottom" or "top" half of the space a full-sized block would occupy, but not vertically in the "left/right" or "front/back" halves of a block's volume.

From the wiki entry:

Slabs are half-blocks. Upside-down slabs occupy the top half of their block space rather than the bottom half. To place a slab upside-down, right-click on the bottom of a "ceiling" block, which can be removed after the slab has been placed, or by right clicking the top half of another block, if the player wishes to place it on the side of another double or single slab block.

Solution 2:

Vertical slabs are not in the game. however, depending on your design, you might be able to use stairs for the effect you need

Solution 3:

The nearest you get to vertical slab is a wall. It can be made only of cobblestone (not smooth stone), manufactured by placing cobblestone in two rows:

 [ ][ ][ ]
 [c][c][c]
 [c][c][c]

The wall occupies slightly more than one block of vertical space, similar to fence, but you can build on top of it, and it occupies roughly half the block width. Unlike slabs, though, you can't fit two walls in one block - a wall normally goes through the middle of the block and adapts itself in shape to neighboring walls similar like a fence or a pane of glass.

There is no direct vertical counterpart to a horizontal slab in Minecraft.