cggart

Thanks for the reply, that seams like a good idea. When you add those layers to the ceiling finish do you then delete the ceiling structure layers, and just not use them? Also is the mud/sill plate counted as a layer? I've seen it added during framing but don't see where its thickness comes into play in these layers?

I understand "Ceiling Finish", and see how it is used , but I don't see that the 5/ 1/2'' (ceiling structure) is used anywhere? The distance between my floor joists and the top of my wall is 5/8, yet the ceiling structure is 5.5 inches? What is the Ceiling Structure number and why does it exists?