My wife wants a wood stove on the main floor instead of the basement. Problem is, there is no hole there. It is a clay lined cinderblock chimney. The local rentall place has a hammer drill with a 5" core dry bit that they say should work. I was reading somewhere that the clay lining requires a core drill.... Does it matter if I use a hammer drill with a core bit? I don't wat to have touble with the clay lining...