Could someone please advise me of how thick you make your fillings and how thick a layer you put under fondant.

I have a 3 tier 21st cake to do this week and they love sugarshacks buttercream but we need to put fondant over the top for the decorations.

Many thanks

My fillings are normally about 1/2 thick.
And my frosting (under fondant) is very, very thin. Hardly any frosting on the outside of the cake.

In my case depends on the fillings. I dont like too overfill them specially on high tiers. The pressure form the heavy
cakes doesnt help with bulgin areas. Even with a dam it can be a problem. If it's too slippery it makes the cake unstable.
So I never put so much in tiered cakes. For single cakes then I can do more..
Edna