From the image you can see that some of my duct work runs parallel to my joists. I would like to run an untreated 2 x 4 cap plate for a wall perpendicular to the joists and under the duct work. I would attach the studs to the cap plate that would be nailed into the joists.
My question; is there any problem with nailing a cap plate into the joists directly under the duct? I will obviously be driving nails into the joist through the sheet metal and the 2 x 4 cap plate will be making contact with the duct, but the nails will be into the joist and not just sticking into the duct.
Thanks for opinions.