Ivy, Thank you for your question on the Delta 9 in. x 7/8 in. Residential Assist Bar in Venetian Bronze. The bar has not been tested for exterior use so as the manufacturer, we cannot recommend this application. Best, Customer Care Team
There is 1 7/8 inches from inside the bar to the wall.
Yes it can be mounted vertically, horizontally or diagonally, whichever suits your needs. (see Picture) Be sure the screws engage the studs or a wooden cabinet to insure the most secure installation.
Seems to me you could use this anywhere that a grab bar is needed for stability. Actually, mounting it near a dog gate is a great idea. Just be sure you mount it so that it engages studs or use anchors that strengthen the mounting reliability.
BAR IS 9"
I think that Delta is in the best position to answer that, how it will respond to constant water exposure. Physically, I would say "yes", it could be done, I would have a tile installer do it, but again, I am not sure how it would respond to that regular water exposure. Call Delta.
call the store and ask.