USG Casting Fireplace Surrounds - Manual (Page 7)

The following diagrams help illustrate the relationship of combustible materials to the firebox opening:
Minimum Mantel Vertical Clearances
There are minimums for clearances for combustible mantel height above a fireplace. NFPA codes for minimum
clearances are as follows:
Reference Mantel Shelf or Reference Mantel from Top
Breast Plate Depth of Combustion Chamber
a 10 Љ A 19 Љ
b 8 Љ B 17 Љ
c 6 Љ C 15 Љ
d 4 Љ D 13 Љ
e 2 Љ E 11 Љ
7 Casting Fireplace Surrounds
fireplace
louvered top assembly
top of combustion chamber
bottom of
top door trim
A
a
B
b
C
c
D
d
E
e