Tin ceiling tiles I once worked on.

 

The main ceiling diameter is just less then two ceiling tiles so half the difference is clipped of all the tiles at once so the main seem runs down the center of the room.

 

I was able to make the shower pipe come right down throw the tile so it is centered on the design.

 

                                       The last couple of tile usually take special trimming .

                                  
                                                        The job is not quite finished