[algored2deth]

Is spraying the foam a DIY project? Anybody with experience with the DIY spray foam packs care to chime in?

You can DIY with tiger foam and a couple other brands out there. The most difficult part is prep and then applying the foam. Make sure that your surfaces are very clean and any water leaks are fixed. I found that it was fairly hard to get an even layer of foam if it is not something you do a lot. I think using the kit can be a pita for the rim joist. For something like you show in your pic, it would not be too bad. Just follow the directions for the spray foam and you are all set.

There was an article in Fine Homebuilding a couple months ago about doing flash and batt, where you spray foam a thin layer (like an inch) and then put FG over it. It is a hybrid approach and may work for your climate. Talk to some others in your area and ask their opinion.

 

[algored2deth]

I would think that you would want to air seal this wall the best you can before putting up the FG. Great stuff may work ok but you will need to go back and trim it so that when you do put up FG, it does not create air voids/irregularities. Could also use caulk and backer material if need be. Make it as air tight as possible.