How thick is the balsa and is there anything supporting it underneath?
The balsa wood we have access to here is rather flimsy and i'm not sure it would handle the weight of anything particularly heavy all that well.
Even with support from the walls below.
Also, do you have the process for spackling the walls up on the nets somewhere?
I'm thinking that my next project (fieldstone) will have some, but I'm not too sure at the moment how to go about it.