I know it's frustrating to create a transparent texture in sketchup while only using one face since applying the color fix with anim8tor makes the opposite side disappear....so I couldn't use grid-like textures for catwalks. But no more.
Soon I'll make a tutorial on how to do it in video, but for now I can try explaining it.
What you need is a grid texture that is seamless like the one I showed above.
1) create a new component which will be one step in the stairs (you can copy it numerous times to make the stairs)
2) Makes sure that you are in monochrome mode and all side facing outwards (the sides you can see) are white.
Now comes the tricky part, this is where you manipulate it.
3) The top square, or part you want to be the grid select it and then right click and select bounding edges.
*Copy it by either ctrl+C or using the move tool and holding ctrl.
**Place it anywhere on the workspace and make it a group.
***open the group and then reverse the face
4) place the group in the same position as it was when you copied it so that it overlaps the other. Now you have two faces in opposite directions.
**You may need to reposition the textures so that they line up properly.
IMPORTANT NOTE: It's recommended that you don't adjust the size of the grid after painting the first texture.