Hi everyone. I'm planning to finish my basement - my first time and I'm trying to plan around how I solve certain problems before I begin. I have a main air duct/return that runs alongside and right up against the foundation wall for most of the length of the wall, right where I need to stick frame next to the foundation wall. Problem is there is no room between duct and foundation wall to frame in between and no access to the joists above to connect a top plate. What would be the correct way to frame a wall in this scenario? Is there a way to install a top plate underneath the duct? I've attached some pics to better show my problem. thanks!
Your best bet might be to frame a wall that will just fit under the duct work and find a method to attach the new framed wall to the foundation wall. L-brackets would work. I have not dealt with insulation in the manner your current wall has it attached...I'm assuming you have more concrete foundation wall behind that insul? In order to finish out the soffitt around the duct work, it looks like you are going to have to attach a 2x4 to the metal beam...you can use a ramset to do that, then you just frame down from the 2x4 and over to your wall to cover the duct work.