• Client: Société des Habous et des Lieux Saints de l’Islam
• Owner's Representative: ICADE Promotion
• Architect: SCP Dubois Jeanneau
• Consulting engineer: AIA Ingénierie
• Manufacturer: Spécial Textile
• Serge Ferrari composite material
> Précontraint 1002 S2
> Surface area: 580 m²
Paris’ Great Mosque, built in 1926, is a listed historical monument. In January 2013, the central patio of this fine structure was covered by a retractable roof to increase reception capacity. An engineering challenge, illustrating the specific advantages of Précontraint 1002 S2 composite membrane in meeting this fine building’s demanding requirements.
Structural engineer AIA Ingénierie and architectural practice in association have given birth to an architectural masterpiece: design and construction of a 29 m long x 20 m wide, double curvature mobile roof, which is virtually invisible when retracted. This ingenious design ensures that the original architecture of this historic building remains unaffected, in agreement with French Ministry of Culture requirements. This retractable roof, which is specifically designed to protect worshippers during Friday prayer, fully respects the history of this place of worship. “We tried to be as discreet as possible in relation to both the existing structure and the roof’s visual impact; Only very minor modifications were made to the original building to allow the roof’s arch supports to fold away”, explains Jean-Marc Marion, AIA Ingénierie’s engineer for complex structures.
Steel structure and Précontraint 1002 S2 flexible composite membrane
This mobile roof comprises two sections, activating complementarily above the north and south sides of the mosque’s central patio. A motorised arch pushes or pulls the standard arches of each roof section to cover or uncover the patio.
The arch rollers initially travel up to a height of approximately 1.80 m in raceways mounted on supporting columns, before the arches themselves start to move.
The 100% recyclable, lightweight material is then deployed in just 20 minutes, offering unrivalled aesthetics. Its S2 surface treatment optimises PVDF alloy performance and limits adherence of pollutants and dirt. Insensitive to UV radiation, the Précontraint 1002 S2 membrane also enhances the natural light contribution (8% translucence).
The structural steelwork comprises 9 lattice arches (4 on north side and 5 on south side) bearing on rails supported by 8 columns founded on the terrace floor slab. The roof closing manoeuvre is driven by 4 motors fitted to the bottoms of the 2 central junction arches Pantographs guide the membrane during movement. All manoeuvres are automatically controlled from an electric control panel (secure system making it impossible to lower the roof, when it is in place, or move the arches, when the rollers are in the lower part of their raceways). The roof activates, when wind speeds are less 30 km/h.