A section of my home has sustained water damage from an improperly installed platform deck. The damaged section includes about 1' portion of a few studs around a window and a 3' section of the sill plate, which rests on the concrete foundation. The entire wall is about 4' high and runs parallel with the floor joists (house is a back split). My intention is to replace the section of sill plate and sister/replace the damaged studs, how concerned should I be about temporarily supporting the rim joist above? Again, this wall runs parallel with the floor joists above, which bear on the adjacent exterior wall and an interior carrying beam with a point load further down this wall. The rim joist above is basically a continuous header, would it even sag at all if a 3' section of studs were removed? My intention is to complete all this work from the outside.
My thought for temporary support. Remove the window and fill it with cripples to the foundation on the unaffected sill plate. Add 1-2 full length studs on the unaffected area to close the gap which would be roughly 3'.
My other thought was to bolt some blocks or a temporary 2x8 header to the unaffected studs which would stick out past the foundation and allow me to wedge temporary supports that will rest on concrete blocks on the ground:
I don't know if I'm overthinking this or if it will be an issue at all but I can't think of any other way to support it - it's not like I can build a temporary wall to support it, but then again, would I even have to?
Also, how important is it to bolt this section of sill back down? Can I just use tapcons if I don't land on a preexisting bolt? Could I also replace it in pieces? Say so I didn't have to remove so much at once?
Thank you for your input.