just googled hearth pad and discovered it is what we call simply, a
hearth.
some links here:
http://hearth.com/questions/qa1593.html
http://groups.yahoo.com/group/woodheat/message/3148
no idea how helpful these will be but it's a start.....don't forget
code requirements when setting stove distances from walls and other
combustible materials etc.
have fun!
Steve - Australia (the Aussie)