Norlite Corporation 628 S. Saratoga Street Cohoes, NY 12047 Phone (518) 235-0030 Fax (518) 235-0233 E-mail: farchambault@norliteagg.com Back Menu Next [Standard Specs] [Introduction] [Physical Properties] [Structural Lt. Wt. Concrete] [Bridge Decking] [Pumping] [Masonry] [Thermal Insulation] [Sound Absorption] [Fire Resistance] [Lightweight Fill] [Other Uses] Fire Resistance of Concrete Masonry Underwriter's Laboratories (UL 618) Standard Building Code BOCA Basic Building Code Building Code Requirements - Medium Slab Thickness for Concrete Floors, Roofs, or Walls Underwriters Laboratories (UL 618) Minimum equivalent thickness and approximate face shell thickness in inches. Type of Aggregate Class D-2 Retardants Class C-3 Retardants Class B-4 Retardants Equiv. Thickness, Inches Face Shell Thickness, Inches Equiv. Thickness, Inches Face Shell Thickness, Inches Equiv. Thickness, Inches Face Shell Thickness, Inches Expanded Clay, coated or uncoated, rotary kiln process 3.60 1 1/4 4.40 1 1/2 5.10 1 3/4 NOTE: The cement-aggregate proportion shall not exceed 1:10 for all units made from rotary kiln processed aggregate. Back to top Standard Building Code (Formerly Southern Building Code) Construction Minimum Equivalent Thickness, Inches 4 Hrs. 3 Hrs. 2 Hrs. 1 1/2 Hrs. 1 Hr. 3/4 Hr. 1/2 Hr. Expanded Clay or Shale 5.1 4.4 3.6 3.3 2.6 2.2 1.8 Back to top BOCA Basic Building Code (Building Officials Conference of America, Inc.) Construction Minimum Equivalent Thickness, Inches 4 Hrs. 3 Hrs. 2 Hrs. 1 1/2 Hrs. 1 Hr. 3/4 Hr. 1/2 Hr.
Expanded Clay or Shale	5.1	4.4	3.6	3.3	2.6	2.2	1.8

NOTE: Equivalent thickness is defined as the average thickness of solid material in the wall and is represented by the formula:

          T= V 
            LxH 

Where:

T = Equivalent thickness in inches
V = Net Volume (gross volume less volume of voids) in cubic inches
L = Length of block in inches
H = Height of block in inches

Net volume (V) of the blocks is to be determined by a water displacement method of a number of blocks of each design. The blocks are to be "soaked" in water for 24 hours, removed from the vat, surface water removed, and then immersed in water and the displacement determined.

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