So… as indicated by the condition of the plywood we had some rot at the bottom plate and rim joist. We had some friendly neighborhood carpenter ants in there as well. This is a good example of how quickly a small maintenance issue can turn into a much larger, and more costly problem. Luckily, I am a professional wood surgeon with a sawzall and a crowbar, so no problem. We evicted the ants, stripped off all the particle board sheathing (this part of the house is 70/80’s era), pulled out the leaky windows and the fiberglass insulation to fully expose the problem areas. All of this work revealed some other issues that were lurking below the surface, so it was time for a game plan.
Typically in renovation, I try to expose as much as will be needed right off the bat, and then try to re-construct it in a way that is as close to the ideal construction sequence as possible, making things as linear and as simple as possible. Since this is my house, and I am doing all the work, I made things a bit more complicated, just for fun. What we found in this part of the house was that we needed to replace the pier footings, repair and re-enforce the rim joist, and re-structuralize (technical term) the floor system.