FIRE RESISTANT MASONRY WALLS

Provisions relating to fire safety and fire resistance represent some of the most important regulations in building codes as far as safety of the public is concerned. The amount of damage, loss of property and life attributed to fires is many times the loss caused by structural failures and even much more than the losses caused by earthquakes...

Listed below are the fire ratings for a number of concrete masonry walls - we suggest you consult your Concrete Masonry Manual for further information on the subject.

TABLE 1:
FIRE RATINGS OF CONCRETE MASONRY WALLS
EXPANDED SLAG OR PUMICE AGGREGATES

special order lightweight block w/pumice

Wight (W)		Fire Resistance Rating
nominal	specified	partial grouted or hollow masonry	solid grouted masonry
4" 6" 8" 8" special 10" 12"	3 5/8" 5 5/8" 7 5/8" 7 5/8" 9 5/8" 11 5/8"	less than 1 hour 1 hour 2 hour 4 hour 3 hour 4 hour	2 hour 4 hour 4 hour 4 hour 4 hour 4 hour

TABLE 2:
FIRE RATINGS OF CONCRETE MASONRY WALLS
EXPANDED CLAY, SHALE OR SLATE AGGREGATES

STD lightweight block

Wight (W)		Fire Resistance Rating
nominal	specified	partial grouted or hollow masonry	solid grouted masonry
4" 6" 8" 8" special 10" 12"	3 5/8" 5 5/8" 7 5/8" 7 5/8" 9 5/8" 11 5/8"	less than 1 hour 1 hour 2 hour 4 hour 2 hour 3 hour	2 hour 4 hour 4 hour 4 hour 4 hour 4 hour