I'm having a bit of a tussle with the people who are drafting plans for my house in Hawaii (2006 IRC). I specified raised heel trusses for my 2:12 roof. Not for increased insulation (days 80 degrees, nights 70 degrees), but for added strength and ventilation. They are saying this is outside prescribed building practices, probably because they aren't used in Hawaii. Neither are they prohibited by the Hawaii County building code.
The truss span is only ten feet, so (according to the Hawaii County building code) I do not need a professional design and stamp. I will use a common truss design with plywood gussets, and the block raising the heel will be a 2x12, 3 1/2" high at the outer edge of the top plate. This will work better with the plywood gussets than a narrow upright. I don't think there's anything stating that the vertical block has to be a 2x4.
So, I guess my question is, does "prescribed building practices" mean something stated in the IRC/local codes or just what people are used to.
The truss span is only ten feet, so (according to the Hawaii County building code) I do not need a professional design and stamp. I will use a common truss design with plywood gussets, and the block raising the heel will be a 2x12, 3 1/2" high at the outer edge of the top plate. This will work better with the plywood gussets than a narrow upright. I don't think there's anything stating that the vertical block has to be a 2x4.
So, I guess my question is, does "prescribed building practices" mean something stated in the IRC/local codes or just what people are used to.