the width of my building/run is 16ft 1-1/4 inch . I am going with a 6/12 pitch roof using 2x4 stock with a 1 1/4 inch depth birds mouth. What is my ridge beam height?

If using a shed roof( pitching one way), height of ridge from top plate will be 96''.

With gable roof and ridge at center line height will be 48''

Chuck

http://i819.photobucket.com/albums/zz111/lacogada/2x4rafter_zps207a665f.jpg (http://s819.photobucket.com/user/lacogada/media/2x4rafter_zps207a665f.jpg.html)