Question about Bluestone

[iDesign]

I'm in the process of designing/building a portico which will have 1.250" thick PA Bluestone veneered over the old poured concrete steps. The risers will be cultured ledgestone. The portico has enough weight/mass to use three (3) permacast fiberglass columns in the front corners about 10" apart. We don't want these columns shifting or moving, so I suggested drilling through the bluestone into the concrete, and then expoxying in some kind of studs that will anchor the matching blocks at the base of the columns. One of the carpenters said that we should check on what the drilling process is so we don't risk cracking the stone even though it's set in mud already. So I thought this would be a good place to ask.

Mike

[tthomass]

If its already set + nice and solid.......drill away (masonry/concrete bit). Bluestone is soft vs slate. If you're close to a corner or edge you may chip/crack/break but what little it would probably wouldn't matter as it will be covered.

[iDesign]

Oh it's set up nice. I was just worried that the stone itself is somehow brittle, and maybe we needed some kind of special wet drill or diamond bit. The hole nearest the outside would most likely be 8" to 10" in diagonally from the corner. The columns are 8" square, with a 10" X 10" seat which would have at least 3+" of stone showing on the two outside edges.