installing grab bar in small shower
I live in an old spanish style house with my 89 year old father who has numerous disabilities. Our one shower is very small and the caregiver has a hard time showering him. We want to install a grab bar, but since the shower is tiled we are having trouble locating the studs. In my father's career he was a plumber and 32 years ago he remodeled the bathroom. With his memory gone we can't ask him to recall the distance of the studs. We drilled into the grout line 16" o.c. from the back wall and came up with nothing. I'm pretty sure the old lath and plaster was removed when the remodeling took place for the bathroom. The house was built around the 1930's. How can we secure a new grab bar that is 18" long on the tile in the shower?
Thanks for any help.