I attempted to make a birdcage cake that was 6'' cakes with a 6''half sphere cake on the top, the total height was around 9 inches.
When I tried to cover it with sugarpaste the sugarpaste ripped at the back, it was a huge tear that was unfixable, I think the sugarpaste was too heavy.
Does anyone have any tips on how to ice such a cake? suggestions would be fab
General rule of thumb is that you can't really cover a cake that is taller than the the width of the cake, so if you used a 6" wide cake, the cake should only be 6" tall, any taller than that and you are going to find it pretty hard to cover. If you are going to be putting embellishments on it, then you could panel it and use the cage elements to hide the seam.