A method of defining a rib structure within an iso-grid composite component according to an exemplary aspect of the present disclosure includes, among other things, defining a first rib at least partially with a uni-tape ply bundle at a first level, the uni-tape ply bundle including uni-tape plies and a first spacer ply, and defining a second rib transverse to the first rib at least partially with a spacer at the first level, the spacer including a second, different spacer ply, the spacer transverse to the uni-tape ply bundle such that the spacer is interrupted by the uni-tape ply bundle.