Lesson Topics 170206 D1 Introduction - Session 1 170206 D1 InterNACHI SOP - Session 2 170206 D1 InterNACHI SOP - Session 3 170206 D1 Roof and Chimney – Session 4 170206 D1 Roof and Chimney – Session 5 170206 D1 Roof and Chimney – Session 6 Next Lesson →