Hello, This is my first post in this forum and I'm just starting to get involved with house repair. I consider myself pretty handy, but any serious projects I've taken on have been on vehicles. Anyway, I recently purchased a 2 story condo that has a slab on grade foundation. The unit was built in 82 and never had gutters. Upon inspection of the home, it was discovered that the underlayment under the siding was rotted due to the 2 story fall of water and low foundation(probably +-12" from the bottom of the siding to the ground). I had the sellers replace the underlayment, apply flashing and install gutters. They used a rubber material that is used for roofing. I can now reach under and feel that there is solid wood directly under the siding, but in some places, this new wood does not seal to the foundation. In these areas, I can feel behind the new underlayment and touch the top of the foundation and what appears to be some remaining rotted wood(seems to be another layer of plywood behind what was installed). So I have 2 questions: Is is typical to have two layers of exterior plywood under the siding? More importantly, what can I do to seal these areas? I was thinking of spraying some expanding foam and then maybe applying some sort of j-channel to the bottom to prevent any further splashing. Although, the gutters should now remove the splashing from the equation. I wish I could post some images, but saw that I'd need 10 posts before that. Thanks in advance and please let me know if there is anything I can clear up.