I have an adjacent horizontal I beam and heating duct trunk I am framing in a soffit. It runs through the center of the room, so there is no wall on either side of the soffit. It is 17ft long and 25.5in. wide (across). I already used 2x2s to create 'ladder' frames along the length of the obstructions to create the sides of the soffit. My question is, what distance should the soffits bottom surface 2x2 studs (for lack of a better term) be positioned from each other? 16in OC, 24in OC? Thnx in advance.

Jim

 

16 inches OC in keeping with standards, usually what is in your house now.