I live in San Marcos, Texas and have an older home built post WWII for returning Veterans. The plumbing is all 1/2" galvanized pipe. My problem is the tile in one of my bathrooms does not allow the single handle mixer valve to protrude sufficiently to turn the knob up enough to allow maximum water flow, I currently have a lavatory handle which does allow for this. My question is, is there anything that will allow the valve stem to protrude enough or a deeper trim ring to resolve this? The mixer valve I have now is by Delta. Any help would be appreciated.