It's a 4x5 arrangement of 2 inch thick 9 inch square Victorian terracotta pammet type tiles.
I still want to avoid modern concrete pointing, which I don't think would suit the tiles. I want either lime or a lime effect, sort of off- white and gritty. My concerns about lime are the drying time (I want to get the stove installed), and whether there's an issue when I seal the tiles - as I think I'll have to do, as they are very matt and porous after acid cleaning (does anyone have ideas on an approproate sealer?). I was thinking maybe snowcrete and sharp sand - has anyone used snowcrete? Is the result off-white or brilliant white?