It's some relatively simple trig related to your pitch plus you have to figure out seat cuts depth, where you are going to snub off the tails, how wide your fascia board is, etc.

Raised heel trusses, depending on the soffit material, I either don't do anything at all, or you can use nailers like sheetrock nailers, between the truss bay. Lotta work though.

Funny how the spell checker underlines soffit and sheetrock. I swear they are real words.

If you don't have a construction master out in the field, it will be tough. Possible but lots of handwritten figuring.

Draw out the side view of your rafter/truss. Say your overhang is 18" at 8" pitch, then the drop will be 12" from the edge of your framing. say the seat cut of your rafter is 6" just to use for ease. so now instead of 12", you are at 6" from your top plate. Now all you have to figure is out on the end of the tail, how far down to you want to snub the long point of your rafter/truss. 1x8's you roughly go 5-6". just say 6". add that to your drop, you get 12" which is where you will chalk the line for the BOTTOM of your nailer. Don't make the mistake of putting it on the wrong side of the line.

Personally, when I do this, if I do this, I would just tack the board on the wall straight, then double check when everything else is framed for the roof to make sure it all comes out right. You will look good if it works right for you, but if you mess up, you will look like an idiot to the builder when you have to take it all down.

 

A Squared+bsquared=c Squared

 

Boy if it works what a time saver great idea I will try that my self

 

Lol