Supporting rim joist

[Steadyhand]

Hi, I need to repair the rim joist on my 99 Legend. I have 4 sections I know need fixed. They are by the front door, back door, and both corners at the north side. The back door is the worst. It is rotted out over a good 8 foot span. About 4 of the floor joists immediately under the door is also rotted on the last 2-3 inches of the boards. My plan is to sister all the studs together using corner ties and then cut off the outer rim joist and replace it with treated lumber. I am fairly confident I have the leaks fixed but I will also be getting a new roof and gutters this spring anyway.

I have two floor jacks. My only hesitation on this job is the supporting of the wall. I want to make sure I will be supporting it properly. I've read to put a board on both floor jacks and use it to support a longer span across the floor joists. My concern however is the outer wall will sag once the rim joist is completely removed. There is only one board for the rim joist and the outer wall rests half way on the rim joist and half way on the ends of the floor joists. With the ends of the joists rotted along with the rim board my concern is the wall will sag for sure.

If anyone has any helpful information or tips to prevent a structural problem please share it. I have everything to do this job so I'm just looking for last minute advice. I've found I can never have enough knowledge about a job.

[Greg]

with only an 8' span you should be ok, keep the joists supported that should help some. You will have some sag until you get the new rim in place but everything should come back into place once the new rim is in.

Greg

[Steadyhand]

Well here are a few pictures of what it looks like right now. It turns out I am going to need a few other things to proceed. I will be doing approximately 12 feet of rim joist by the back door alone. Once it is done I have to repair the wall studs as well. Don't mind the placement of the jacks in the last photo. I had to use them to jack the blocking into place because it was sagging a bit there so by jacking the blocking into place it leveled out the floor right there. We decided to build blocks between each joist to make it more sturdy and it gives me several places to screw in the rim joist later. We can fix the rim joist and wall studs but to fix the bottom sill plate and floor would require tearing out everything inside as well which we can't do right now.

[Greg]

It's a Pandora's box, once you open it up you are committed and you don't know where it will lead.

Greg