In this methodological paper, we present a framework, which was developed in an action research project where mathematics teachers and vocational teachers collaborated with a researcher. With this epistemic framework we challenge the view where mathematics is taken-for-granted as the theoretical knowing which is applied to the practical vocational knowing. The purpose of the framework is to aid teachers and researchers to capture theoretical and practical aspects of mathematical and vocational knowing, both when the subject areas are separate, and when they are intertwined, in collaborative teaching. This way, power relations between different teaching contents may be reconstructed, which is helpful for collaborative teaching, and for students' learning in both mathematics and vocational teaching content areas.