Fire Ratings

Fire Ratings

  PRINT

2005 NATIONAL BUILDING CODE FIRE PERFORMANCE RATINGS
FOR UNITS OF METRIC CONFIGURATION

 

Concrete Block Standard Aggregate

TYPE OF UNITNOMINAL THICKNESSEQUIVALENT THICKNESSRATING IN MINUTES
Hollow 100 mm 66 mm 54
Solid 100 mm 90 mm 86
Hollow 150 mm 80 mm 66
Semi-Solid 150 mm 113mm 120
Solid 150 mm 140 mm 177
Hollow 200 mm 103 mm 99
Semi-Solid 200 mm 142 mm 180
Solid 200 mm 190 mm 272
Hollow 250 mm 121 mm 130
Semi-Solid 250 mm 180 mm 258
Solid 250 mm 240 mm 344
Hollow 300 mm 144 mm 182
Semi-Solid 300mm 220 mm 315

 

Composite Walls

TYPE OF UNITEQUIVALENT THICKNESSRATING IN MINUTES
Face Brick + 100mm Hollow Block 154 mm 195
Face Brick + 150mm Hollow Block 170 mm 243
Face Brick + 150mm Semi-Solid Block 195 mm 279
Face Brick + 200mm Hollow Block 193 mm 276
Face Brick + 200mm Semi-Solid Block 232 mm 332
Face Brick + 250mm Hollow Block 211 mm 302

 

NOTES:

  • Equivalent thicknesses quoted in the above values are for concrete block manufactured to meet CSA A 165.1 - 04 Standards. Concrete Block not complying to these standards should be computed independently.
  • Equivalent thickness value for brick in composite wall section is for a solid unit. Performance ratings for cored brick may differ.

 

Fire Testing - Brick Vs. Vinyl & Fiber Cement

The fire tests, conducted at the Southwest Research Institute in San Antonio, were done in accordance with ASTM E 119, the Standard Test Method for Fire Tests of Building Construction and Materials. Each of the tested materials was used to construct a typical exterior house wall section, which was then subjected to fire for one hour or until one of the failure criteria was met. Failure takes place when the wall collapses, flame or hot gas penetrates the wall, or when the temperature rises to 250°F or greater on the unexposed (interior) side of the wall.


The hollow brick were the only materials to pass the test, achieving a one-hour fire-resistance rating for the wall. The vinyl siding burned away, failing the test after only 18 minutes and exposing the underlying house structure to the flames. Surprisingly, the fiber cement siding, which homeowners and builders often assume to be adequately fire-resistant because of its concrete-like composition, also failed the test and could not withstand the flames for a full hour.