1/4x3/8" square notched trowel is the minimum you must use. By the time you properly set the tile into the mortor you ll be as flush as you can get.If this is a notched tile ( even slightly notched) you my have to back butter the tile or at least smooth coat it to get the proper coverage...GL

3/4 - 3/8 - 1/4 = 1/8. The mortar may be too thin to do the job properly.

why are you trying something you have no idea what your doing and steve is trying to help you of a guess do you want it to be a waste of money and look like crap tile is not a diy project if i gave you a list of the exact material and verbal instructions you cant fake it one of my helpers of one year ruined his mothers bf house trying to do what he watched happen every day for a year anyone whos told you it ez is a fool its not your so worried of elevation which is irrevilavent you say your gonna thinset your backer board which is 1/2 if you dont use the special faseners it will fall apart i like to help but i have a reputation to keep i suggest you try linoleum please dont attemt tile youll ruin the existing floor and cause 1000s of dollars in repairs

Hi,

How do you match 3/8" porcelain tile with 3/4" hardwood flooring. Assuming we have to put down 1/4" cement board first (with thinset underneath), what thickness trowel should we use for mortar?

Thanks