SPOTLIGHT

While designing the fire safety of the building, effective compartmentation

A plethora of codes and standards related to the fire safety of curtain wall systems help designers and consultants to choose the right one that suits their needs. In India, the NBC 2016 which is the accepted code of practice by all. Construction professionals recommends that for buildings featuring glass façade assembly, all gaps between floor slabs and façade assembly shall be sealed at all levels by approved fire-resistant sealant material of equal fire rating as that of the floor slab to prevent fire and smoke propagation from one floor to another.

Though it doesn’t provide any specific standard test method for demonstrating the fire rating of the assembly, the standard test method as defined in ASTM E2307, for determining the fire resistance of perimeter fire barriers using intermediate-scale, multistory apparatus satisfies the compliance requirements laid down in the code. Furthermore, NFPA 101, 2018 clause 8.3.5.4.1 mentions that the voids created between the fireresistance-rated floor assembly and the exterior curtain wall shall be protected with a perimeter joint system that is designed and tested in accordance with ASTM E2307 Test Standard.

Third-party certification laboratory listing directories guide on right system selection for the perimeter firestop system. One of the examples is the Intertek certification directory.

To choose the right system, it is important to know the basic details of the application such as the makeup of the exterior wall - spandrel glass, aluminium panel, etc., hourly rating, joint width, static or dynamic joint, etc. The Intertek directory follows a specific nomenclature system to identify the different firestop assemblies listed. based on which right system can be chosen to suit the specific needs of the project. For e.g., when the system is numbered as ‘HI –BPF -120 -12’, it is to be read as:

• HI - Company identifier (Hilti in this case)

• BPF - Barrier, Perimeter Fire

• 120 - Rating of 120 min (F- Rating)

• 12 - 12th system tested in this grouping for the company

UL certifications for perimeter joint systems uses a unique nomenclature which is an alpha-alphanumeric identification system.

The first two alpha characters, CW, identify the perimeter-fire containment system used at the interface of a fire-rated floor and a non-fire-rated exterior curtain wall. The third alpha character is either S or D where S signifies perimeter-fire containment systems that do not have movement capabilities (i.e., Static) and D signifies fire-containment systems that do have movement capabilities (i.e., Dynamic).