Protecting an Icon: Fire Safety at Sheikh Zayed Grand Mosque

Located in Abu Dhabi, the Sheikh Zayed Grand Mosque is the largest mosque in the UAE and one of the largest in the world. It is a landmark known well beyond the UAE, welcoming worshippers and visitors from around the world and accommodating more than 50,000 worshippers. In 2025 alone, the mosque welcomed 6.85 million guests.

For a landmark of this scale, the infrastructure supporting daily operations needs to perform reliably. In the basement parking area, ventilation and smoke extraction are an important part of the mosque’s fire-safety provisions.

Invicta ANARA was appointed by Parsons Corporation to redesign and replace the existing ventilation and smoke extraction ductwork, which had been severely affected by its underground location.

The original GI ventilation and smoke extraction ducts were installed within trenches embedded below the basement concrete slab. As the basement was located below the water table, seawater had entered the underground duct network, resulting in severe corrosion and deterioration.

A pumping system had been introduced to remove accumulated water, but this did not resolve the underlying exposure. Continued operation along the existing route would leave the ductwork vulnerable to further deterioration. The replacement system therefore needed to move the ductwork away from the water-affected underground trenches while maintaining connections to the existing mechanical equipment.

As the main contractor, Invicta ANARA was responsible for redesigning and delivering the replacement fire-rated ventilation and smoke extraction system while working within an operational basement parking environment.

The new ductwork could not follow the original underground route. Invicta ANARA developed an above-ground arrangement using the available ceiling space between the building’s structural I-girders. The new system needed to accommodate fresh-air supply and smoke extraction ducts while connecting with the existing fans in mechanical rooms at the far end of the car park.

The installation also required:

• New wall openings through the structural diaphragm wall to establish the required connections.
• Removal and rerouting of existing sprinklers, cable trays, lighting and other services that conflicted with the proposed duct route.
• Closure of openings associated with the redundant underground ductwork.
• Removal of existing louvre towers.
• Careful coordination with the structural elements and existing building services within a restricted ceiling zone.
• A finished appearance compatible with the existing parking environment.

The ducts were positioned flush with the underside of the I-girders, with the exposed surfaces finished in a colour selected to complement the surrounding structure.

Invicta ANARA delivered the complete Durasteel® fire-rated ductwork package, covering system design, material supply, installation, testing and final commissioning. The completed system provides the specified one-hour fire resistance for both the supply-air and smoke-extraction routes.

For the smoke extraction system, high-performance insulation board was installed internally within the ductwork. This provides thermal protection to the surrounding concrete structure in the event that hot smoke passes through the extraction system during a fire.

The overhead ductwork was installed directly beneath the I-girders to achieve a closely aligned finish. The exposed surfaces were coated to complement the surrounding interior, helping the fire-rated system integrate discreetly into the basement parking environment.

Coordinated Air Distribution

Fire-rated metal grilles were supplied and installed across the air-supply and smoke-extraction network. Each grille was balanced to support consistent airflow and effective smoke extraction throughout the parking area.

The project team also coordinated the construction of multiple wall openings between the mechanical rooms and car park. Openings associated with the redundant underground system were closed, while the existing louvre towers were removed.

Existing sprinklers, cable trays, lighting and other services that conflicted with the new routes were removed, capped or rerouted as required.

This integrated approach allowed the replacement ventilation system to be installed within a highly constrained ceiling zone without treating the ductwork as an isolated package.

Architectural Integration

Extensive curved cladding was installed around sections where the Durasteel® ducts passed beneath the inverted T-beams.

The cladding incorporated illuminated advertising boards, creating a more integrated ceiling treatment while providing a practical visitor-facing feature within the parking area.

The project delivered a robust, maintainable ventilation and smoke extraction solution, designed around the existing building infrastructure and operational requirements.

Key outcomes included:

• Enhanced durability of the ventilation system
• Improved access for future inspection and maintenance
• Optimised use of the available ceiling space
• Effective coordination with existing building services
• Improved visual integration within the parking environment
• Reliable fire-rated performance
• Complete delivery from design through commissioning