Laying cut limestone on concrete
I am replacing a porch that was torn off of my 1820's brick house. I have a stonemason who has duplicated the old limestone foundation blocks, and we have faced a concrete porch form with them. now, we need to cap the porch with 3" thick cut limestone blocks. Around the perimeter the blocks are 36" x 16", and inside the perimeter the field blocks are 12" x 24" Everything is 3" thick. My question relates to laying the limestone blocks on the concrete. I assume a mortar bed, but would a large notched trowel be the way to go? I have reservations about just plopping down a mud bed and trying to level all these blocks, as it seems as you go along, there would be no place for the mortar to go, whereby with a large notched trowel, it would be somewhat like laying giant tiles, and the notched trowel would make room for the mortar to spread out. Don't know if this will work, though.
Any experience with a situation like this, or any advice?