I can't drill more than one inch in to a chimney breast. I've borrowed a better (non SDS) mains drill but a masonry bit with hammer on doesn't make a dent beyond that initial one inch. It hits something with a different sharper sound. Have tried a metal drill bit - nothing. If I shine a torch in it looks dull grey.
I've seen a few posts about this, with the suggestion being to get (someone with) an SDS drill, better bit and to push through . But before I do that I wanted to check that this isn't the chimney lining?
The attached picture is from underneath (mantel on the right) and shows the lintel is about four inches with what I presume is the plaster board straight on top, just under an inch thick. I presumed the brick or stone above the lintel would be equally as thick, and as far as I can feel up before the lining starts is the same depth as the lintel. So there should be four inches of *something* safe to drill in to behind the plaster before I hit the lining of the chimney?
The house was built around 1920 and this is an original fireplace.
The flue for the wood burner goes off the side before it goes up, so is clear, and the fireplace has nothing like a heating system connected and there are no electrics around this area.
Could the lintel be pre-cast concrete? Was that used in 1920/21? If it is probably safe to go through, any suggestions on how to drill whatever this is?
Thanks,
Richard.
