[Cob] roof first, roof second...posts?

[Tys Sniffen]

Hey folks,

 

My wife and I are deep in planning stages for our *huge* cob house project.
Well, not that huge, but maybe bigger than some.  Anyway, we're trying to
decide about the roof.  Whether to build it first, and then build the walls
up around it, or build the cob walls up and use them as the load bearing
part to hold the roof up.  

 

Some other facts we are considering:

- We intend to use a metal roof, for lightness. (light roofs seem like a
good idea here in N. CA- earthquake country

- we have plenty of long, straight trees to make into beams and posts, so
it's not about size or cost when it comes to that

- we're currently imagining a two level roof. if you were looking at the
short end, it would look like the left (north) half of the house was shorter
than the right (south) side. I'm actually thinking about two, parallel, (one
on top of the other) ridge beams. 

- there will be solar panels on the south side, so some weight will be an
issue. 

 

Anyway, maybe I'm getting ahead of myself; what's the general consensus:
posts and roof first, or walls first?

 

Tys