I was going to use sections of the dimensional lumber I have around - the studs are all 2.5"x4" - hard to make that work with 2x4's. I will add PT studs as sisters. I wasn't going to add a plate on top of the sill, there wasn't one originally. You think that would be wise?
I am going to do the rest of the sill, just not until after we get back from Barbados.
Another detour today - since I started aligning the barn doors, I decided I needed to address the floating center post
Had to cut out 16" of the dimensional 4x4 center post, and about 12" of the dimensional 2x4" door frame/posts. Fortunately I have saved sections of old posts I've cut up for other areas, so I had sufficient lengths to get clean sections for here. I tied two 2x4 together to get the center, set that on a piece of pressure treated sill, and then added the side posts
The external plates needed to be actual 1x, so I got 5/4" x 6" decking & cut the width down to 4.5", to get the total 9" width needed
Covered the center area with butyl wrap before putting the external plates in
Replaced the wood screws with 3" 5/6" lag bolts, so that should hold up. Don't have any in the left door yet, ran out of time & light. I'll deal with that after work tomorrow.