Stonework question

[Cheesehead]

I've got my base set up for a corner build, along with a 20' run of block for a retaining wall.

For the outside finish, I'm thinking of mortaring stone to the block. I've got a stone house, and dug up a patio made of the same limestone so I've got a really large amount of the same rock as the house. I'd like to finish both the oven and a retaining wall with this rock.

But I've got a couple of questions...

First - How thick can my mortar between the CMU (concrete block) and the stone be? My stone ranges in thickness from about 4" to 1". I'd like to use 3" and under thickness, but I'm wondering if I can have 2+" of mortar behind a 1" thick rock (which I'd need if I mixed 3" with 1" and want them to come out the same distance). If I have to keep all the stone the same thickness I'll have to take a little more care to make sure I have enough.

This rock doesn't split, and I don't have the tools for splitting it, although it does cut pretty reasonably with a diamond concrete blade & skilsaw.

Second - I'm assuming that I can just mortar straight onto the CMU, but for cement board enclosing the dome I'll need to fasten a metal mesh first. Correct?

Thanks much. I hope to start pouring this week, I'll try to post some pics!

Edit - or is this post better in the "Design Styles, etc." forum?

[brickie in oz]

Originally Posted by Cheesehead

First - How thick can my mortar between the CMU (concrete block) and the stone be? My stone ranges in thickness from about 4" to 1". I'd like to use 3" and under thickness, but I'm wondering if I can have 2+" of mortar behind a 1" thick rock (which I'd need if I mixed 3" with 1" and want them to come out the same distance). If I have to keep all the stone the same thickness I'll have to take a little more care to make sure I have enough.

You can use 1" stone although thicker would be better.
Fill in behind the 1" stone with stone rubble and mortar (a lot of old buildings were constructed this way).
Secure the stone to any substrate with ties or anchors every 600mm (2') vertically and horizontally, probably overkill but it better that way.