i need to assemble and stick a small gum paste garden shed for a garden theme cake. i cave cut out and let the pieces dry out and am nervous about puting it together. Any help on this would be appreciated please.

use boxes etc to support the shape till its fully set

you have two options re joining the pieces together;-
royal icing
gunge (gum paste let down with egg white till it resembles well chewed chewing gum)

the edible glues only work if one or both pieces are fresh - as your pieces need to be fully dry before assemble this medium is not an option

i apologise for late reply, but thank you for your help

I usually glue the gumpaste pieces to themselves when I have enough time for it to fully dry because it is stronger than royal icing. But I always keep royal icing on hand for last minute repairs. Since you will need to dry the pieces in advance you will want to glue the pieces together with a small piece of fresh gumpaste and a dab of water on each side. As long had you give the piece plenty of time to dry (I dry all of my pieces in the oven with the oven light on) and support them well while drying, it should be solid as a rock.

Another trick I sometimes use is to 'pre-drill' holes in the pieces for toothpicks. That way if I need toothpicks for added support the holes are already there and I don't have to worry about cracking the gumpaste.

thank you for your help. unfortunately i had to have the cake ready by last sunday, so as i hadnt had any replies in time , i wemt ahead and supported it with styroform. i would much preferred to do ALL EDIBLE shed, so will do it your way next time, and thanks once again.