Attaching Rafters on structural beams, nails or screws?

So here is the scenario ,
We are building a roof on a log house, With A cathedral ceiling.
So there are large diameter logs with flats sawn on them that correspond to the 10/12 pitch . There is a ridge beam and three purlins on each side. We put 2 x 6 tongue and groove red pine decking on top of that for the ceiling finish. after that we are going to fasten 2×4 plates on top of the purlins and ridge (over the decking) and sit 2×8 rafters on top of those 2×4 plates. And then the spray foam guy comes.
The large logs will have plenty of structural strength, the 2×8 will be sitting on the ridge and 3 other purlins. My partners Are big on screws, and I want to put nails. The house will move eventually once it dries and settles. the rafters wont support that much (short spans between the purlins).
My code book just says how
many nails per rafter if I were to
toe nail screw through a birds mouth, no details at all for
my situation.
Replies
hangers & nails
Mostly I'm a nail man so I won't really take sides except to say if you use screws just be certain to use screws rated for that particular use. I've had a difficult time finding that particular info about most screws, probably a lawyer thing because screws that are too hard can fail, like, catastrophically snap. Mostly nails pull out before they shear off.