How Should the Joint Width Be Designed When Installing Decorative Panels?

The joint gap design of GRC decorative panels is a key technical element in ensuring the safety and aesthetics of curtain wall systems. Based on 28 years of installation experience, Qinglong Group holds that the joint width must be determined comprehensively based on factors such as thermal deformation, construction tolerances, and seismic action, and is typically controlled within a range of 8-15mm, with appropriate adjustments possible in special cases.

Thermal deformation is the primary basis for joint gap design. The deformation amount is calculated according to the material's thermal expansion coefficient (GRC is approximately 8-10×10⁻⁶/°C) and the local maximum temperature difference. In the Shenzhen Yirui Biotechnology Building project, Qinglong Group set the joint width at 12mm to accommodate the local annual temperature difference of 40°C, ensuring that panels have sufficient expansion and contraction space under temperature changes. For extra-large panels (length exceeding 5m) or specially shaped panels, the joint width should be appropriately increased to 15-20mm to prevent extrusion damage caused by cumulative deformation.

Construction tolerances need to be absorbed through the joint gaps. Qinglong Group requires installation errors to be controlled within ±3mm, so the joint width must account for error accumulation. In the Nanning Wuxiang China Resources MixC One project, we simulated the installation process using a BIM model, setting the theoretical joint width at 10mm, with actual construction controlled within 8-12mm. This flexible design both ensures the visual effect and leaves room for installation adjustments.

Structural deformation under seismic action must also not be overlooked. According to the GB50011 code, in areas with a seismic fortification intensity of 7, the joint width must take into account the influence of the inter-story drift ratio. In the hotel project in Algeria (seismic fortification intensity 8), Qinglong Group increased the joint width to 15mm and used flexible sealant for filling, ensuring that panels have sufficient deformation capacity under seismic action.