I am having a hard time finding anyone to address this issue. I own a 75 yo house in washington state which has a very old addition added on. This addition has been made into a bedroom and the other half is a shop area. There is no real crawl space, the floor was built up about 18" off the ground. Until last year the wood floor has been sturdy for 40yrs or more, however, we had an outdoor leaky faucet, which created water damage on our interior drywall, then later we noticed the floor over the shop area is soft and sagging. I don't believe there is a true foundation, I've only seen some cement type bricks around the perimeter of this addition. Where do I start? We'll rip up the floor, but will we have to dig out a crawl space and put in new floor support, or do we need to actually build a new foundation also? Help, please.