Currently have 3/4 osb subfloor on 24" joists with some reinforcement cross bracing. i want to try and make the tile as flush as possible. What thickness thinset is needed for ditra? Is it 1/8 underneath then 1/8 membrane, then another 1/8 on top plus tile? Or is the membrane + thinset 1/8 total?

[color=#000000]Hi all,[/color] [color=#000000]I have a shower wall with a 1-1/2" square cut out for a hand-held spray fitting. Unfortunately the hose connector which attaches to this cannot fully seat because the fitting is not in the center of the cut-out. I need about 1/4" additional cut out (which as you can see would be trimming a bit of the TOP of the tile just below the fitting).[/color] [color=#000000]See photo. Please, what is the correct method and tool for trimming some of the tile while in place?[/color] [color=#000000](Note: I can't move the fitting; it's hard-plumbed behind the wonderboard and rigidly in place. However if I get a 10mm Allen wrench I can at least remove the brass fitting, exposing the nipple and giving myself a little work space.)[/color] [color=#000000]Thanks for your help! I have ZERO experience cutting, trimming or even installing tile. This mistake was made by a bath contractor who has disappeared. I really don't want to pull out the tile. I'm also posting in Plumbing forum.[/color] [i]The fitting is practically resting right on top of the tile beneath it. I need a good 1/4 to 1/2 inch gap there.[/i]