My house was built in 1931, so here's an example: a two by four was still two inches by four inches, and in houses built in the seventies and newer, a two by four is actually one and a half by three and a half. Also, the wood used to build my house, the cells and rings are closer together, than in newer construction.
But, yes, some structural reinforcement would probably be a good idea if I have the tank in the main house.
Has anybody else actually done this in oregon Or am I pioneering in this state?