Hi guys, Over concrete, what's the thinnest mortar bed you've used to set bluestone? Usually I'll do a 2" thick stone around the edge and infill with 1-1/2" so I end up with most of the bed being about an inch. I do a slurry, then a real dry mortar bed, set the stone, pull up the stone, slurry the stone, reset stone. I have an existing stair condition where I have to add bluestone treads on top of existing concrete. Due to existing conditions I have to keep the mortar bed as thin as possible to keep the riser height reasonably uniform. What's the thinnest mortar bed you've successfully used? Has anyone used pre-mixed mortar with admix (think notched trowel)? I'm in a freeze-thaw area. TIA.