Raised edge trims do not allow the water over the edge into gutters. They should be fitted on top of single battens that have been fixed to the fascia, as there doesn’t need to be a gap for a gutter to sit in. Fix ALL adhesive should be used to bond the trim to the batten on the vertical face, and nails used to fix the horizontal face onto the roof decking.
Don’t nail through the face of the trim – this will show through the final topcoat finish on the front face. To join two lengths together simply overlap (by 50mm) and slot two pieces together using Fix ALL adhesive to bond together, then tape and resin over the joint with woven tape.