What Is the Appropriate Wall Thickness for GRC Components? What Problems Can Occur If It Is Too Thin?

In the engineering application of GRC components, wall thickness selection has always been a core concern shared by owners, general contractors, and designers—choosing too thin raises concerns about insufficient strength and poor durability, while choosing too thick increases self-weight and drives up costs. Many projects have experienced later-stage cracking and falling safety hazards due to improper control of wall thickness parameters. As an industry service provider with nearly 30 years of deep expertise in the GRC field, we draw on our experience participating in drafting the Technical Standard for Glass Fibre Reinforced Cement (GRC) Building Applications, together with measured data from over a thousand completed projects, to outline a clear selection logic for you.

First, it is important to clarify that GRC components have no unified fixed wall thickness standard; parameters must be matched across three core dimensions: application scenario, shape complexity, and installation environment. For conventional flat exterior wall decorative components, a common wall thickness in the 8-12mm range meets the needs of most scenarios. For special-shaped components such as double-curved or carved designs, where local shapes involve bends and contours, the wall thickness is recommended to be no less than 10mm to avoid stress concentration in thin-wall sections. For special working conditions such as coastal or high-altitude environments with strong winds and severe corrosion, or large components exceeding 1.5㎡, the wall thickness needs to be increased to 15-20mm, together with corresponding reinforcement rib structures. Many peers blindly recommend thin-wall products below 8mm to drive down quotes—it may seem to cut costs, but the subsequent risks are extremely high.

Next, let us focus on the three core problems directly caused by GRC components with insufficient wall thickness, all common issues summarized from after-sales rectification cases of past projects. First is insufficient structural strength: impact and deformation resistance drop sharply, so edges and corners are prone to chipping during demolding, transportation, and hoisting. At the high-altitude installation stage, thin components' wind load resistance falls far short of national standard requirements; in extreme wind conditions, panel surfaces easily deform, and in severe cases they may even fall off and cause safety accidents. Second is greatly compromised weather resistance: the core protective capability of GRC comes from the density of the substrate itself. Excessively thin walls result in insufficient protective layer thickness over the internal glass fibre mesh layer; after long-term exposure to outdoor rain and acidic/alkaline environments, the fibre layer corrodes and expands rapidly, and panel surface pulverization and cracking typically appear within 3-5 years, directly shortening the component's service life. Third is difficulty in controlling processing precision: GRC components with wall thickness below 6mm are prone to uneven shrinkage during curing, causing deviations in the flatness and curved surface conformity of the final product, making it difficult to align with the keel structure during on-site installation, which instead increases construction costs and delays the project schedule.

Many project owners wonder: since too thin is risky, is thicker always better? Actually, no. GRC components with wall thickness exceeding 25mm have a unit self-weight over 50kg/㎡, which not only greatly increases the load-bearing pressure on the building structure, but also makes installation procedures exponentially more complex, raising overall engineering costs instead. Proper wall thickness matching should be based on meeting national standard requirements, combined with differentiated structural design according to the component's specific load-bearing points. For example, the localized thickening process we adopted in multiple landmark projects applies targeted wall thickness reinforcement at installation points and stress concentration zones while keeping reasonable parameters in other areas—controlling self-weight while ensuring overall structural strength.

As a drafting unit of the national standard for the GRC industry, we also advise project owners in the industry: when purchasing and selecting GRC components, do not focus only on unit price parameters. Require suppliers to provide corresponding wall thickness simulated load test reports, as well as documented completed cases for the relevant scenario, to avoid being misled by low-priced, low-quality products. Currently, many peers in the industry are also exploring wall thickness optimization for GRC. As long as such process upgrades comply with GB standards and GRCA industry specifications, they are directions worth recognizing—the core principle is always safety first and suitability for the scenario.

### FAQ 1. What are the reference wall thickness values for GRC components in different scenarios? 8-12mm for conventional flat exterior wall components, no less than 10mm for special-shaped carved components, and 15-20mm for large components under special working conditions. 2. What is the minimum wall thickness for GRC components? Below 8mm is not recommended; products optimized with special processes also need corresponding reinforcement structures and complete load test reports. 3. Is a thicker GRC component always better in quality? No. Wall thickness exceeding 25mm greatly increases self-weight and installation costs. Properly matching the scenario with targeted structural design is the optimal solution. 4. How soon will quality problems appear in GRC components with insufficient wall thickness? In conventional outdoor scenarios, pulverization and cracking may appear within 3-5 years; under extreme working conditions, the timeframe is even shorter.