Laserfiche WebLink
public way that consists of a sidewalk. This satisfies the intent to provide an area for fire <br /> department operations. <br /> Water curtains have been used prescriptively to prevent fire spread through non-rated glazing <br /> and vertical openings. Water curtains are allowed through an ICC-ESR for non-rated glazing, and <br /> prescriptively in atrium, escalator, and stair openings as a means to prevent vertical spread of <br /> smoke and heat through openings between floors. With the latter conditions, vertical fire spread <br /> through floor openings is substantially more challenging to mitigate than horizontal fire spread as <br /> is the case with these exterior walls. Therefore, the water curtain strategy can successfully be <br /> applied for these exterior wall conditions. <br /> In addition, the north and east exterior building walls are of non-combustible construction. While <br /> the walls are not constructed as a fire-resistance-rated assembly, the doors are designed to be <br /> self-closing and are fire-resistance-rated. This means that the "opening" portion of the wall <br /> prescriptively meets the rating requirements for openings in a fire-resistance-rated wall. These <br /> walls do not contribute to fuel load or fire spread from the building to the adjacent yard, or vice <br /> versa, should a fire occur in the vicinity of the north and east exterior walls. <br /> To prevent the spread of fire to the exterior walls, the building is fully-sprinklered per NFPA 13 <br /> and the requirements of OSSC 412.3.6 Exception 2. This means that a minimum sprinkler density <br /> of Extra Hazard Group I is provided, which is a robust system providing high-density discharge <br /> that would be adequate for a hazardous storage warehouse that is twice the size. This density is <br /> intended for fire extinguishment, as opposed to fire suppression; rather than merely keeping a fire <br /> at bay until the fire department arrives. With this type of fire sprinkler protection throughout the <br /> building, a fire will be extinguished quickly at the location of origin, preventing spread to other <br /> areas of the building, including the exterior walls that are additionally protected with closely- <br /> spaced sprinklers. When considering the role and capacity of the building sprinkler protection in <br /> addition to the water curtain mitigation provided, this combined system is more than equivalent to <br /> meet the requirements of a passively protected 2-hour exterior wall. This strategy increases the <br /> overall building safety and reduces potential for fire spread. <br /> 6 SUMMARY <br /> As detailed above, the installation of water curtains along the north and east exterior walls will <br /> provide protection equivalent to that of a 2-hour fire-resistance-rated wall by cooling the surface <br /> of the wall and obstructing the passage of radiative heat to the unaffected side. In addition, the <br /> building is of non-combustible construction with fire-resistance-rated openings as required. The <br /> building is fully-sprinklered per NFPA 13 to meet the minimum density of Extra Hazard Group I, <br /> which is intended for extinguishment in the area of the fire as it occurs, preventing spread to other <br /> areas of the building, including the exterior walls. <br /> Therefore, it is requested that this alternate strategy be accepted as providing protection <br /> equivalent to that of a 2-hour fire-resistance-rated wall assembly. <br /> Please contact me directly with any questions regarding this review. <br /> Franklin Callfas % cr`k <br /> f` President/Fire Protection Engineer <br /> `r' Intuitive Engineering Services - ° <br /> franklin@intuitivefire.net <br /> 541-848-1798 <br />