I have a Harman Accentra pellet stove on the way to be installed in a few months and I was wondering if it was possible to make a hearth pad by using concrete. The pad would be going over the top of the existing hardwood floors and be 4 inches thick. I was thinking about making it following concrete counter top instructions and installing molding in the form box to give it a little bit of detail along with black dye to get it to resemble cast iron as much as possible. After reading a few articles on R-values and other construction ideas I wasn't sure if just plain concrete would cut it. Any feedback on my idea would be great. Thanks