HELLO, i would like to know if its possiable to connect copper to galvanize or just run galvinize for hot water pipe. house is old. pipes are galvinize. under the house is galvinize piping. under floor board. house is built on pillars.two feet of room under house to mve in. because I need to reroute the plumbing. also floor is old in kitchen and I would like to lay ply- wood over old floor. How thick should I use.