full size wood mantlet (5 in+) 12 inches away from the fireplace openings top? US - TX fire code
&quot;Not within 6 inches&quot;
&quot;Within 12 inches, 1/8 inch projection per inch from the opening&quot; So,
7 inches away, can stick out 7/8 inch
10 inches away, can stick out 1-1/4 inch
12 inches away, can stick out 1-1/2 inch
13 inches away, stick it out as far as you like.
Not confusing at all, IMHO.
TLDR: No you cannot have a 5 inch mantel 12 inches from the opening.