85-03-01136
ML39
Page
25
Horizontal Clearance Reduction by 66%
NPFA 211 Approved
: Install 20-gauge or heavier steel shield that
provides at least a 1”
active airspace, on the combustible wall
surface. To provide for active airflow, install at least 1” metal or ceramic s
tandoffs or spacers between the metal shield and the
combustible surface being protected. The bottom and top edges of the cavity between the metal shield and the combustible
surface must be left open. The steel
shield must be a minimum of 12”
larger in each direction than the surface area of the
source of heat; or if the surface being protected is smaller than surface area of the source of heat, this shield must be larger
than the combustible surface in each direction.
By using this method of protection, if the required horizontal clearance was 16
”
, the resulting clearance will be reduced by 66%
to 5-3/8
” between the heat source and the metal shield.
Horizontal Clearance Reduction by 50%
NPFA 211 Approved
: Install an R-1 rated ceramic board or R-1 rated mineral board on the wall you are attempting to protect.
by using this method of protection, if the required horizontal clearance was 16
”
, the resulting clearance will be reduced by 50%
to 8
” between the heat source and the
R-1 Rated wall board.
Clearances to Combustible Mantels
A
n 8” combustible man
tel may be installed at a minimum of 51" above the floor level of this Fireplace. Non-combustible
(marble, brick, stone, metal etc.) mantels can be installed at any desired height above the top convection air opening. Any pre-
existing combustible mantel must fall within the approved mantel profile chart.
WARNING:
Make proper use of this chart. Do not compromise the specifications contained in this chart.
Failure to adhere to proper clearances required to combustibles may cause spontaneous combustion of the mantel and may
result in a fire causing property damage, personal injury or loss of life.
NOTE:
For mantels that protrude more than 8 inches from the front surface of the fireplace use a rise and run of (1:1) to
calculate the required height to the mantel.
EXAMPLE:
You have a 12" mantel. To calculate the height above the convection air opening the equation
would be: (Depth of Mantel)
–
8” + 5
1
” = (Height above the floor of the fireplace)
12” –
8” + 5
1
” = 5
5
”
DO NOT deviate from this minimum clearance requirement. Doing so can lead to a severe fire hazard.
Figure 3-19 Mantel Clearances
