Replies

1. 
   Piffin | Apr 29, 2003 01:49am | #1

   The mantle being the projecting shelf above the firebox openning, I am not aware of code restrictions for amount of projection or height other than that combustables must be a minimum of eight inches away from the openning at the face. It may be that perpenmdicular projecting combustables must be further away.

   A hearth must project 18" from the front and 12" to either side.

   This is based on my understanding of natioinal standards, having never worked in PA. Your local bldg dept is your best source. Masons and wood stove stores in the area should also be knowledgeable.

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2. 
   NickNukeEm | Apr 29, 2003 05:44am | #2

   According to the code check book, there must be "1 inch of clearance for each 1/8 inch projection of combustible material surrounding the fireplace opening to 12 inches." 

   In regular language, that means that for a 3/4 inch thick combustible projection (a board, such as the start of your surround, or mantle,) it must be clear of the fireplace opening by 6 inches (6/8ths.)  For a 1.5 inch thick combustible projection, it must be clear of the opening by 12 inches (12/8ths.)  It's a sliding scale where you add the number of eigths of the combustible material, and that's the number of inches required.  There is nothing specific regarding the shelf.  Treated as a projection, if the shelf is >1.5" wide, it must be above the opening by at least 12".   (Unless you have a very tall opening, this restriction should not be a problem.  It you do have a tall opening, you'd want the shelf higher to maintain proportion and balance.) 

   That's according to the code check.  Take Piffin's advice and call the local building department to check on any local ordinances.

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