What Is the Typical Thickness of GRC Panels for Curtain Walls? Thickness Selection and Design Specifications Explained

The thickness of GRC panels used for curtain walls directly affects component strength, weight, and safety in use. Panels must be selected scientifically based on component dimensions, load conditions, and the service environment, so as to avoid risks caused by insufficient thickness or waste caused by over-design. Clarifying the conventional thickness range and selection criteria is key to ensuring curtain wall quality and economy. Drawing on 28 years of project practice, Qinglong analyzes thickness specifications and key selection points.

I. Conventional Thickness Range of GRC Panels for Curtain Walls

According to the Technical Standard for Building Application of Glass Fibre Reinforced Cement (GRC) (JGJ/T423-2018), the conventional thickness range of GRC panels for curtain walls is 15-30mm, with different base thicknesses corresponding to different scenarios. Small flat components (dimensions ≤1.5m×3m), such as decorative mouldings and small curtain wall panels, use a thickness of 15-20mm; medium components (dimensions 3m×3m to 4m×6m), such as conventional curtain wall panels, use 20-25mm; large irregular components (dimensions >4m×6m) or heavy-load components such as hollow carved panels use 25-30mm. In Qinglong's Sanya Yingbin No.1 project, 20mm thick GRC panels successfully met the requirements of 3m×4m curtain wall panels. In special environments such as strong coastal wind areas, an additional 2-5mm should be added to the base thickness to enhance wind load resistance.

II. Key Factors Influencing Thickness Selection

Thickness selection requires comprehensive consideration of core factors such as component dimensions, load conditions, and shape complexity. The larger the component, the greater the thickness required to avoid excessive deflection; for example, large 4m×6m panels require a thickness of ≥25mm. Qinglong's test data show that 25mm thick GRC panels achieve a deflection ≤L/250 under a 4m span (L is the span), meeting standard requirements. In terms of load conditions, the higher the wind resistance grade and the greater the seismic intensity, the greater the thickness required; for example, in force-9 typhoon areas, an additional 3mm is needed on top of the conventional thickness. In terms of shape complexity, hollow and carved components, due to their weakened cross-sections, require 5-10mm more thickness than flat panels; for the GRC panels with a hollowing rate exceeding 50% at the Ouargla Hotel in Algeria, a thickness of 50mm was selected to ensure structural strength. In addition, GRC panels requiring integrated insulation can adopt a composite thickness design (GRC facing panel + insulation layer), with the facing panel thickness kept at 20mm to satisfy both decorative and structural requirements.

III. Practical Cases of Thickness Selection in Different Scenarios

Different project scenarios have markedly different thickness requirements for GRC panels, calling for targeted selection. Conventional curtain walls of commercial complexes: 20mm thick flat GRC panels are selected to balance strength and lightweight design, as in the Guangzhou Dongzhu Shangdu Commercial City project, where 20mm thick panels suit multi-point hanging installation; irregular curtain walls of cultural landmarks: 25-30mm thick panels are selected for complex double-curved shapes, as in the Guangxi New Media Center's double-curved panels, where a 25mm thickness ensures the stability of the curved form; coastal high-salt-spray environments: 22-25mm thick panels are selected to add weather-resistance redundancy, as in the Hainan Poly Peninsula No.1 project, where 25mm thick panels suit the marine climate; interior decorative curtain walls: 15-20mm thin panels are selected to reduce self-weight and cost, as in the interior GRC decorative panels at Nanning Wuxiang China Resources MixC One, where a 15mm thickness meets the requirements of use. Through precise selection, Qinglong achieves material cost optimization while ensuring safety.

IV. Thickness Design Optimization and Quality Control

Thickness design can achieve precise matching through structural optimization, avoiding excessive material use. Incorporating internal steel mesh or glass fibre mesh reinforcement enhances strength without increasing thickness; in Qinglong's Dongting Lake Museum project, 20mm thick GRC panels with internal steel mesh achieved strength comparable to ordinary 25mm thick panels. Optimizing the shape design reduces cantilever lengths and spans, lowering thickness requirements; finite element analysis software is used to verify thickness, ensuring that strength and deflection requirements are met. During production, thickness deviation must be strictly controlled within an allowable deviation of ±1mm; dedicated thickness measuring tools are used to inspect every panel, and substandard products are strictly prohibited from leaving the factory. Qinglong's automated production lines achieve a thickness control precision of ±0.5mm, ensuring that the selected thickness is precisely implemented and guaranteeing long-term stable use of the curtain wall.