For a fireplace with a larger opening of more than 6 square feet the icc requires a hearth that extends 20 inches or more in front and 12 inches or more along the sides.
Tile in front of fireplace code.
0 56m the hearth extension shall extend at least 16 inches 406mm in front of the facing material and at least 8 inches 203mm beyond each side of fireplace opening.
The firebox is where the actual fire will be and it must be lined with the appropriate materials that will meet building codes.
This is illustrated in the diagram below courtesy of the fine folks at code check.
2114 3 masonry built fireplaces 4114 3 10 all combustible mantels and similar trim shall be kept at least 6 inches from the fireplace opening.
It is the part that is most visible.
National standard building code information.
In the absence of local codes we suggest your installation clearances meet or exceed the national standard building codes or the national fire code.
The surround is the front facing portion of the fireplace.
The hearth design must be.
Tile is not recommended for applications that will exceed 175 f 80 c so it s not an option for the firebox.
Combustible materials and trim must be at least 6 inches from the firebox opening.
2114 3 masonry fireplaces where the fireplace opening is less than 6 sq ft.