I recently had about $4000 in damage done to my house because of the cheap pot metal fill spout on my tub. A hole was eaten in the back of it due to various chemicals in the water and every time the tub was used water would squirt out the back into the wall. There is no telling how long this had been going on until the hole had gotten large enough so I could tell it was wetting the floor in my closet. Since it happened I found that this has also happened to several of my neighbors. Tub plumbing now has an acces door in the closet and gets check often.
Jimmie