Check my rafter calculations?

I've a 10' x 6' shed with 7/16" sheathing on all sides. I'm putting on a gable roof with a ridge board. The gable gable ends are on 10' sides. so my building width: 120.875" ridge board thickness: 1.5" (it's 2x8 nominal) pitch: 12/12 my rafters are 2x6 nominal, 8' length Question 1 I think the correct seat cut length is 3.9375", is that good? I screwed up my first pattern board for my common rafter by not accounting for the sheathing. I don't want to make another mistake with much more rain inbound this week. I want as long as an overhang as possible, therefore I'm making a 45 degree cut as close to the edge of the rafter boards where they'll interface with the ridge board. Identifying where to cut the birdsmouth is I guess my real challenge and where I'm struggling. From the very edge of the top of cut board I'm measuring 84 13/32" down, marking that point, drawing a plumb line (which is 45 degrees) down. Along that line I'm finding the perpendicular, level, line which is the length of the seat cut. Question 2 - is that length correct? and method ok? submitted by /u/whistlerbrk [link] [comments]

May 10, 2025 - 14:30

I've a 10' x 6' shed with 7/16" sheathing on all sides. I'm putting on a gable roof with a ridge board. The gable gable ends are on 10' sides.

so my building width: 120.875"
ridge board thickness: 1.5" (it's 2x8 nominal)
pitch: 12/12
my rafters are 2x6 nominal, 8' length

Question 1 I think the correct seat cut length is 3.9375", is that good?

I screwed up my first pattern board for my common rafter by not accounting for the sheathing.

I don't want to make another mistake with much more rain inbound this week.

I want as long as an overhang as possible, therefore I'm making a 45 degree cut as close to the edge of the rafter boards where they'll interface with the ridge board.

Identifying where to cut the birdsmouth is I guess my real challenge and where I'm struggling.

From the very edge of the top of cut board I'm measuring 84 13/32" down, marking that point, drawing a plumb line (which is 45 degrees) down. Along that line I'm finding the perpendicular, level, line which is the length of the seat cut. Question 2 - is that length correct? and method ok?

submitted by /u/whistlerbrk
[link] [comments]