I am in the process of rocking my fireplace and have a problem. My contractor told me I could use cement board and mortar hearth and stone directly to it (without using a scratch coat and wire mesh). I have a done 1 fireplace in my lifetime using the scractch coat method (over tar paper and sheetrock) and everything turned out great. Last night I got all of my cement board up and started with my hearth stone. I buttered the hearth stone with approx 1/2" of type s mortar and laid it directly on the cement board ( I wiggled it in there and put some pressure on it). Well I came back this morning and was able to pick up every piece of stone I laid
. The mortar barely adhered to the stone or cement board (I was able to pry it off pretty easily)> Should I be using type N mortar or do I need to go the scratch coat direction. Thanks for any information you can lend to me.