Phil,

1.- Only the first floor is cinder block. The second floor is what I
want to build.
2.- By framinng I meant exterior framing. Not sure that we want to
divide the space inside.
3.- By lateral support I meant exactly that. Bowing out. (new word
for me).
The idea is that the 4x8 ridge will sit on 4x4 post on both end to
support the weight, in order not to "bow out"
4.- The city inspector (where I got the permit) told me that it can not
be taller than 18 feet and that is why I am thinking on 8 feet in the
center and 6 feet on the side.
5.- You are right we could have a middle support. My concern was that
my wife or son could hit the post.

Thanks.

Claudio