Behind our bathroom sink we only have a fingerwidth space between the sink and wall mirror (ceiling to tile surface directly behind sink)- no backsplash! Water frequently accumulates in this small tile space which is hard to keep dry if there is no back splash for faucet and easily happens just washing hands etc; the lowest part of the mirror has some changes too due to frequent moisture. Yes we will adjust water pressure etc but in the meantime I'm looking for the best barrier to use on the tile surface and mirror (clear sealant adhesive or caulking and type or any other suggestions?). I think best would be to change mirror and put in tile backsplash eventually but until time and money allow, what barrier would work best for tiny area against a mirror wall on top of tile that gets frequent moisture?