Question: I recently acquired a free standing fireplace and need some info on how to install. Do I use the hearth measurement of a woodstove or is there somewhere I can find information on this? Thank you for any help you can offer. Answer: You can probably use the NFPA or other applicable codes for the size of the floor pad. General wisdom would say that you'd want about 18" in front of the open side of the fireplace, and approx 12" around the sides that do not open. The exact construction of the floor pad is another matter. This depends on the construction of the fireplace, which determines how much downward radiation would occur. Most fireplace installers could get a good idea of this by looking at the construction of the fireplace - how far the hearth is off the ground, how many layers of sheet metal and air spaces, etc.