I was trying to hang a shelf on the wall in my living room and was drilling holes to plug fishers in it. Accidentally I found myself drilling into part of the flue of the fireplace (people living in the apartment below me have one). The hole dapth is less than one inch and I immediatly changed the position of the shelf.
The drill didn't actually pierce all the way through the flue wall as I can clearly see the bottom of it.
Is this condition dangerous? Should I warn the people living below me? I want to fill that hole, what material should I use? I don't think I actually went all through the flue fall, but would this cause the part around the hole to overheat?
Thanks for the help.