14 x 24 roof rafter question

[knightasylum]

I am planning to use the Optional Raised Roof at Loft plan that came with my house plans, and want to make sure I am reading it right (in terms of how it affects the shell material list) the roof rafters for this optional plan (for an area that can get a good amount of snow) calls for 24 rafters at 2x12x12, is that correct?
Thanks,
Scott

[MountainDon]

Your area may or may not receive more snow load than the design was calculated for. A better more accurate answer would require your ground snow loads in psf or your geographic location.

[MountainDon]

A snow load look up is available here

[knightasylum]

I appreciate the suggestion  my question isn't as much about my area -  the design i received with my plan states that I should use 2x12 (as I read it) unless the snow load is light or none which then I could use 2x6. so I am planning for the heaviest load by using the plan recommended 2x12. The plans are just not super-clear on that so I was asking in relation to the sheet that i received with the plan is the recommendation for the addition roof rafters at 2x12x12?

PS the snow load look-up for my location on the linked page involves at $35 fee, which is fine but not something I want to pay at the moment in relation to the plan question.

[John Raabe]

If you are using the Enchilada plan and building the Raised Roof option on page E-6 in the booklet then the roof joists are 2x12 for full insulation but they also add stiffness. The ridge board in that configuration is not working as a beam but does help lock the rafters together. The rafters are triangulated with the collar tie and the rafters are attached with a metal clip to the top of the balloon framed wall. The wall is braced by the loft floor system.

This is a more complex roof and some builders like to use a structural ridge beam and provide a center post to cut down the span to something around 12'. That beam should be sized locally to meet the snow and wind loads.

If you do the standard loft where the loft floor joists are nailed to the bottom of the rafters that will lock the whole roof system into a rigid triangle and you would have plenty of structure for a heavy snow load.

[knightasylum]

Thanks, your first paragraph  confirmed what i was thinking so I believe I am on the right tack with it as far as my material list changes. The roof build I am nervous about but I like the E-6 design (and the extra space it gives) so I think i will go ahead and tackle the more complex design. 
Thank you