I know this has been discussed before but I'm still confused on building my own hearth pad. I don't know what is best to use as far as cement board. It looks like there is Hardibacker, Wonderboard, Durock, and another product called Micore. I'm installing a Jotul 500 Oslo. I know there are hearth pads out there you can buy for $500-$600 but I don't want to spend that much. My friend tells me that a lot of these cement boards should not be used for hearth pads. He bought his hearth pad for $200-$300. I still would prefer to build my own. Sorry if this has already been discussed many time but I'm getting confuse. Any advice would be appreciated. Thanks