Hi, just got done framing all my walls, only thing left is the heating ducts... Here's my situation.. I have the 2 main heating ducts running next to main joist down middle of my basement.. I want to box them all in, they hang down approimatley 12inches from floor joist's.. The width ranges from 4 feet to a lil over 8 feet wide, with the majority being 6-8 feet wide, so its a big section to box in.. They run the entire length of basement about 45 feet... I was planning on boxing it in with 2x4's since it's such a big aread.. and lay 2x4's on their side along bottom to conserve headroom and sheetrock them.. Any suggestions at all to help me make this as easy as possible... I didnt really have to build many sofits, so not real expirieced at it.. Any tricks to make it square and level.. Should I build it on floor or in place? Really need some help with this one, really appreciate all the help you guys are giving me....

 

Normally, a 2x4 on its side is only good to span about 4 feet. However, you can probably cheat a bit. If you cheat, space them a bit closer together than you normally would (so each doesn't have to support as much weight). If you can find some way to attach them to the joists in the middle of that 8-foot span, you'll probably be okay.

It's usually recommended to build it on the floor and raise it, but I like building it in place (especially if you don't have a few strong friends to help you lift it). Strive to be very precise so that you get a flat and level ceiling. I like using 1/2" sheathing for the vertical part, attached to a 2x2 screwed to the joists, and a 2x4 at the bottom of the sheathing. The cross pieces are then attached to the 2x4 with long screws.