Recent project to hang some adjustable shelf units in the bedroom closet by screwing them into the old chimney bricks (the chimney comes up the middle of the closet).
So I was trying to drill holes about 2 inches deep for plastic plugs. I managed to get a few in before the drill bit hit SOMETHING which it could not penetrate - at all - in many places along the chimney (many feet apart but no clear pattern). The something was within 1 inch of the surface.
I was using a masonry bit which worked fine in other places/brick walls/etc.
I stopped drilling after hitting this in a few places, not wanting to make more of a mess if no good would come of it.
Any ideas what could be in there that is so hard? Some sort of stone or metal perhaps? I thought chimneys were just brick (1930's terraced house) but apparently not.
Thanks Dave