BNBC 2020 Compliance Requirements for Fire Rated Glazing in Chattogram Commercial High-Rises
Chattogram’s commercial high-rises, particularly those in the Agrabad Commercial Area and along Nasirabad, are required by BNBC 2020 Part 8 Chapter 2 to incorporate fire-rated glazing in critical egress paths. These corridors and stairwell enclosures must maintain structural integrity during a fire event to allow safe occupant evacuation and facilitate firefighting access. Local building authorities strictly enforce a minimum 60-minute fire resistance rating for such glazed elements, with both integrity (E) and insulation (I) performance often mandated depending on the compartment’s proximity to escape routes.
Antifires’ glazing systems are engineered to meet these stringent demands. For instance, the 26mm door glass assembly—comprising a multi-layer structure of 5mm glass, 5.5mm gel interlayers, and additional 5mm panes—achieves 89–90 minutes of integrity and 68 minutes of insulation, exceeding the 60-minute baseline. The systems are installed within G.M.S. hollow steel frames using ceramic wool (density 210 kg/m³) and intumescent fire seals (20mm × 4mm), ensuring that the entire assembly—not just the glass—performs as a unified fire barrier. This is critical in high-rise scenarios where pressure differentials (maintained at 0 ±2Pa in furnace tests) and thermal expansion can compromise unsealed gaps.
For Chattogram contractors, specifying these tested assemblies simplifies the building plan approval process. The combination of integrity and insulation ratings ensures that glazed partitions in stairwells not only prevent flame penetration but also limit heat transfer, maintaining tenable conditions for evacuation over the required duration.
Selecting Fire Rated Glass Integrity and Insulation Grades for Chattogram’s Humid Coastal Climate
Chattogram’s coastal location, with its high humidity and saline atmosphere from the Bay of Bengal, presents unique challenges for fire-rated glazing systems. Moisture ingress can degrade intumescent interlayers, leading to delamination or reduced fire performance over time. In this environment, selecting EI-classified (insulation) fire rated glass is critical, as these products incorporate laminated gel layers that provide both thermal protection and moisture resistance. The 15mm FPOS glass, for example, uses a multi-layer tempered structure with intumescent gel that resists humidity while delivering up to 132 minutes of integrity and 33–34 minutes of insulation.
The choice between integrity-only (E) and insulation (EI) ratings depends on the application. For enclosed spaces like internal corridors or fire-rated lobbies, EI glass prevents radiant heat transmission—a key factor in limiting fire spread. According to test standards, insulation failure occurs when the unexposed side’s average temperature rise exceeds 140°C or the maximum exceeds 180°C. In Chattogram’s humid conditions, the gel interlayers in Antifires’ 21mm FPOS glass (120 minutes integrity, 30 minutes insulation) maintain optical clarity and structural stability, as verified in tests conducted at relative humidity levels of 43%–90%.
For projects near the port or in coastal zones, specifying laminated fire-rated glass with proven moisture resistance reduces long-term maintenance risks. The table below summarizes key options for Chattogram’s climate:
| Product | Integrity (min) | Insulation (min) | Structure |
| 10mm FPOS | 135 | 16 | 3mm float + 4mm gel + 3mm float |
| 15mm FPOS | 132 | 33–34 | Multi-layer tempered + gel |
| 21mm FPOS | 120 | 30 | Multi-layer composite insulated |
Engineering Demands for Fire Rated Glass in Chattogram EPZs and Hotel Developments
Chattogram’s Export Processing Zones (CEPZ) and the growing hospitality sector near Patenga Sea Beach require fire-rated glazing that addresses both fire resistance and additional load demands. In EPZ facilities, factory floor offices and administrative blocks often require fire-rated partitions and doors that can withstand blast overpressure or impact while maintaining compartmentation. Similarly, hotel atriums and glazed fire barriers in high-occupancy zones demand systems that balance aesthetics with robust fire performance.
Antifires’ fire-rated glass systems are engineered for these dual demands. The 50mm and 54mm ultra-high-performance glass assemblies, for example, achieve EI120 ratings (120 minutes integrity and insulation) using multi-layer insulated structures. These products are installed within G.M.S. hollow steel frames anchored with M6/M8 bolts at 300–600mm spacing, providing structural rigidity that resists both thermal deflection (measured up to 152mm toward the furnace in tests) and mechanical loads. In hotel applications, the glass maintains optical clarity for atriums while meeting the compartmentation requirements of BNBC 2020 for fire barriers between guest rooms and common areas.
For industrial settings, the systems incorporate ceramic wool (3mm–6mm) and intumescent seals to prevent gap penetration—a failure mode observed in tests via cotton pad ignition or sustained flaming. This engineering ensures that even under extreme conditions, the glazed assembly contains fire within its designated compartment. Chattogram contractors can integrate these solutions into factory floor layouts or hotel designs, supported by detailed shop drawings that specify expansion gaps (3mm–5mm filled with ceramic fiber) and frame tolerances.
Antifires Localized Support for Chattogram Contractors: BNBC Testing and Technical Drawings
Antifires provides comprehensive support for Chattogram-based architects, contractors, and developers to streamline compliance with BNBC 2020. This includes BNBC 2020 compliant test certifications for all fire-rated glass products, detailing the specific fire resistance ratings (e.g., E60, EI60, EI120) achieved under controlled furnace conditions. Each certification references the applicable standard—such as BS 476 Part 22 or BS EN 1634-1—and includes data on thermocouple placement (9–12 Type K channels in the furnace, 10–55 on the unexposed surface) and test duration (up to 135 minutes).
Technical documentation extends to detailed shop drawings for fire-rated door and window frames, specifying G.M.S. hollow steel sections, fire-rated insulation boards (12mm–15mm), and intumescent fire seal placement (20mm × 4mm). These drawings help contractors ensure correct installation, including the 3mm–5mm expansion gap filled with ceramic fiber, which is critical for maintaining integrity during thermal expansion. Antifires’ warehouse in Dhaka ensures fast delivery to Chattogram port via established logistics routes, reducing project delays and supporting local compliance verification for building plan approvals.
On-site technical consultation is available to address Chattogram-specific challenges, such as adapting frame anchoring (M6/M8 bolts at 300–600mm spacing) to local construction practices. This localized approach ensures that fire-rated glazing systems are not only compliant but also practically installable, meeting the rigorous inspection standards of Chattogram’s building authorities.