I have scissor trusses connected to ICF walls. The attic space at the peak of the truss is a little over 3'. Two questions:

1) How would you insulate the attic to attain at least R50? Does blown in insulation work with scissor trusses or does the insulation fall to the corners? Will I have to use the batts?

2) How can I best insulate the gable ends of the truss system so that the walls match the R-Value of the ICF? Recommendations?

Edit: 8/12 pitch.

I've been assured that the blown in insulation (cellulose) will be fine in my scissor truss (bottom pitch is actually 6:12). I'm going to go with that in the attic.

not sure if its too late for you (assuming it is) but my gable end detail with ICF puts the truss sitting on the concrete, and then 2.5" of foam sheathing is added to the exterior. This not only insulated, but also aligns the foam with the ICF so the siding material can continue over it. The inside is then furred out so that the face of stud is flush with the face of inside foam, again so gyp can continue past. Spray foam or blow in insulation into the stud bays.

We used 2x12 to stud the gable ends so too late for part one (the 2.5" foam) but not for part two. Does the loose blown in in the stud bays do a better job than bats? I was planning on using two R20 bats in the bays.