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1. Fire Protection Data (continued)
TABLE NO 43-B
Rated Fire-Resisitive periods for various walls and partitions
| Minimum Finished Thickness Face-to-Face2 (in inches) |
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| Material | Item Number | Construction | 4 hr. | 3 Hr. | 2 Hr. | 1 Hr. |
| Brick of Clay or Shale |
1 | Solid units (at least 75% solid). | 8 | 63 | 4 | |
| 2 | Solid units plastered each side with 5/8" gypsum or portland cement plaster. Portland cement plaster mixed 1:2-1/2 by weight, cement to sand. | 4-3/44 | ||||
| 3 | Hollow brick units5 at least 71% solid. | 8 | ||||
| 4 | Hollow brick units5 at least 71% solid, plastered each side with 5/8" gypsum plaster. | 8-1/4 | ||||
| 5 | Hollow (rowlock6). | 12 | 8 | |||
| 6 | Hollow (rowlock6) plastered each side with 5/8" gypsum or portland cement plaster. Portland cement plaster mixed 1:2-1/2 by weight, cement to sand. | 9 | ||||
| 7 | Hollow cavity wall consisting of two 4" nominal clay brick units with air space between. | 8 | ||||
| 8 | Hollow brick units at least 60% solid, cells filled with perlite loose fill insulation. | 8 | ||||
| 9 | 4-in, nominal thick units at least 75% solid backed with a hat-shaped metal furring channel 3/4 inch thick formed from 0.021-inch sheet metal attached to the brick wall on 24-inch centers with approved fasteners; and 1/2-inch TypeX gypsum wallboard7 attached to the metal furring strips with 1-inch-long Type screws spaced 8 inches on center. | 54 | ||||
| 10 | Cavity wall consisting of two 3-inch nominal thick solid clay units with air space. | 8 | ||||
| Hollow Clay Tile, Non-load bearing. load-bearing (End or Side Construction) |
11 | One cell in wall thickness, units at least 50% solid, plastered each side with 5/8" gypsum plaster. | 4-1/4 | |||
| 12 | Two cells in wall thickness, units at least 45% solid. | 6 | ||||
| 13 | Two cells in wall thickness, units at least 45 percent solid. Plastered each side with 5/8" gypsum plaster. |
7 | ||||
| 14 | Two cells in wall thickness, units at least 60% solid. Plastered each side with 5/8" gypsm plaster. | 5 | ||||
| Hollow Clay Tile Load-bearing (End or Side Construction) |
16 | Two cells in wall thickness, units at least 40% solid. Plastered one side with 5/8" gypsum plaster. | 8-1/2 | |||
| 17 | Two cells in wall thickness, units at least 49% solid. | 8 | ||||
| 18 | Three cells in wall thickness, units at least 40% solid. | 12 | ||||
| 19 | Two units and three cells in wall thickness, units at least 40 percent solid. | 12 | ||||
| 20 | Two units and four cells in wall thickness, units at least 45% solid. | 12 | ||||
| 21 | Two units and three cells in wall thickness, units at least 40% solid. Plastered one side with 5/8" gypsum plaster. | 12-1/2 | ||||
| 22 | Three cells in wall thickness, units at least 43% solid. Plastered one side with 5/8" gypsum plaster. | 8-1/2 | ||||
| 23 | Two cells in wall thickness, units at least 40% solid. Plastered each side with 5/8" gypsum plaster. | 9 | ||||
| 24 | Three cells in wall thickness, units at least 43% solid. Plastered each side with 5/8" gypsum plaster. | 9 | ||||
| 25 | Three cells in wall thickness, units at least 40% solid. Plastered each side with 5/8" gypsum plaster. | 13 | ||||
| 26 | Hollow cavity wall consisting of two 4" nominal clay tile units (at least 40% solid) with air space between. Plastered one side (exterior) with 3/4" portland cement plaster and other side with 5/8" gypsum plaster. Portland cement plaster mixed 1:3 by volume, cement to sand. | 10 | ||||
| Combination of Clay Brick and Load-bearing Hollow Clay Tile |
27 | 4" brick and 8" tile. | 12 | |||
| 28 | 4" brick and 4" tile. | 8 | ||||
| 29 | 4" brick and 4" tile plastered on the tile side with 5/8" gypsum plaster. | 8-1/2 | ||||
| Concrete Masonry Units8 |
30 | Expanded slag or pumice. | 4.7 | 4.0 | 3.2 | 2.1 |
| 31 | Expanded clay or shale. | 5.7 | 4.8 | 3.8 | 2.6 | |
| 32 | Limestone, cinders or air cooled slag. | 5.9 | 5.0 | 4.0 | 2.7 | |
| 33 | Calcareous or siliceous gravel. | 6.2 | 5.3 | 4.2 | 2.8 | |
| Glazed or Unglazed Facing Tile, Non load-bearing |
35 | One 2" unit cored 15% maximum and one 4" unit cored 25% maximum with 3/4" mortar filled collar joint. Unit positions reversed in alternate courses. | 6-1/2 | |||
| 36 | One 2" unit cored 15% maximum and one 4" unit cored 40% maximum with 1/8" mortar filled collar joint. Plastered one side with 3/4" gypsum plaster. Two wythes tied together every fourth course with No. 22 gauge corrugated metal ties. | 6-3/4 | ||||
| 37 | One unit with three cells in wall thickness. cored 29% maximum. | 6 | ||||
| 38 | One 2" unit cored 22% maximum and one 4" unit cored 41% maximum with 1/4" mortar filled collar joint. Two wythes tied together every third course with No. 22 guage corrugated metal ties. | 6 | ||||
| 39 | One 4" unit cored 25% maximum with 3/4" gypsum plaster on one side. | 4-3/4 | ||||
| 40 | One 4" unit with two cells in wall thickness, cored 22% maximum. | 4 | ||||
| Glazed or Unglazed Facing Tile, Non load- bearing |
41 | One 4" unit cored 30% maximum with 3/4" vermiculite gypsum plaster on one side. | 4-1/2 | |||
| 42 | One 4" unit cored 39% maximum with 3/4" gypsum plaster on one side. | 4-1/2 | ||||
Notes to Table 43-B
aGeneric fire resistance ratings (those not designated by company code letter) as listed in the Fire Resistance Design Manual, Tenth Edi tion (1981), published by the Gypsum Association -- may be accepted as if herein listed.
1Staples with equivalent holding power and penetration may be used as alternate fasteners to nails for attachment to wood framing.
2Thickness shown for brick and clay tile are nominal thicknesses unless plastered, in which case thicknesses are net. Thickness shown for concrete masonry is equivalent thickness defined as the average thickness of solid material in the wall and is represented by the formula:
|
Where: TE = 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 |
Thickness includes plaster, lath and gypsum wallboard, where mentioned, and grout when all cells are solid grouted.
3Single-wythe brick.
4Shall be used for nonbearing purposes only.5Hollow brick units 4-inch by 8-inch by 12-inch nominal with two interior cells having a 1 1/2-inch web thickness between cells and 13/4-inch-thick face shells.
6Rowlock design employs clay brick with all or part of bricks laid on edge with the bond broken vertically.
Back to 1. Fire Protection Data
The NW Masonry Guide Table of Contents
Masonry Institute of Washington
Washington State Conference of Mason Contractors
