Why Should GRG Components Be Stored Vertically After Demoulding? What Problems Does Flat Placement Cause?

Why Must GRG Components Stand Upright After Demolding? A Complete Breakdown of the Hidden Dangers of Laying Them Flat

During the production and transfer of GRG (glass fiber reinforced gypsum) components, many contractors new to shaped decorative components wonder: a GRG semi-finished product fresh out of the mold is not yet fully cured, so why does general industry practice require it to be stored and transported upright right away? If you lay it flat for convenience, what irreversible impacts will that have on subsequent installation and use? As a professional service provider with nearly 30 years of experience in producing and installing shaped building materials such as GRG and UHPC, we draw on our delivery experience from nearly one thousand GRG projects in venues and commercial complexes to break down this core detail of industry practice.

I. First, Understand: What State Are GRG Components In Right After Demolding?

Many people misunderstand the curing logic of GRG, assuming that demolding means the component is fully formed and can be stacked however they like. In fact, the demolding point in the standard production process refers to the stage at which the component has reached basic demolding strength and can leave the mold smoothly without instantly breaking. At that moment, the hydration reaction of the gypsum matrix is less than 60% complete, the interior still contains a large amount of free water, and the overall stiffness can only support the component's own basic weight, with extremely weak resistance to deformation. The stacking method at this stage directly determines the component's final geometric tolerance accuracy and is the core prerequisite for achieving seamless interior installation later—the misaligned joints and uneven curved surfaces seen in many projects often stem from mistakes made during post-demolding storage.

II. The Core Dangers of Laying GRG Components Flat Go Beyond Mere Deformation

To save transfer space and make loading and unloading easier, many manufacturers lay freshly demolded GRG components flat directly on the ground or on transfer racks. It looks convenient, but in fact it plants three layers of hard-to-reverse quality problems: The first is irreversible gravity-induced deformation. GRG components are mostly customized curved, shaped structures with a typical thickness of 15-25mm. When laid flat, the component is supported only by a limited contact area at the bottom, and the suspended parts will slowly sag under their own weight and the flow of the still-uncured material inside. Even if corrected after full curing, micro-cracks will already have formed inside; after installation, under temperature and humidity changes, local cracking can easily occur. In past project maintenance, we found that even large GRG ceiling components 30mm thick can sag more than 2mm at the edges after lying flat for just over 4 hours—an error completely unacceptable in venue projects that demand seamless finishes. The second is damage to the component's stress balance. During GRG production, reinforcing ribs and installation embedments are pre-set on the back. When the component lies flat, the embedment areas become local stress points, and prolonged pressure can cause the bond layer between the embedments and the gypsum matrix to separate. After installation, this can easily lead to safety hazards such as embedments falling off and components dropping. Such internal damage is hard to spot with the naked eye at factory inspection and often only surfaces months after installation. The third is surface appearance defects. When laid flat, the finished surface of the component touches the ground or the transfer rack directly, and the not-yet-fully-cured gypsum surface can easily be pressed into dents or contaminated with impurities. Later repairs not only add extra time to the schedule, but it is also very hard to make the repaired area fully match the original component in color and texture, compromising the integrity of the overall curved decoration.

III. The Correct Operating Standards for Upright GRG Storage: Industry-Common Practical Details

According to GRG industry production standards, the upright storage angle of demolded components must be controlled between 75-85 degrees—components must not be leaned fully vertical—to avoid bending the reinforcing ribs on their backs. At the same time, the support points of the upright rack must align exactly with the positions of the reinforcing ribs on the component's back, and the spacing between support points must not exceed 60cm to prevent excessive local stress. In our production process, we match each customized component with its dedicated upright rack in advance; even for shaped curved components, customized supports are prepared based on the component's stress points ahead of time, ensuring that the component's geometric tolerance stays within 0.5mm throughout the entire curing process and safeguarding joint precision in later installation at the source.

In fact, whether it is GRG, GRC, UHPC, or other shaped building materials, detailed control during the production process is the core of the final result. Many peers in the industry are also gradually optimizing such production-side operating standards. Only by fully verifying every easily overlooked small step can complex shapes truly be realized with precision.

Frequently Asked Questions 1. Can GRG components that have already been laid flat be salvaged? If they have lain flat for no more than 2 hours and the component is smaller than 1 m², it can be moved to a dedicated upright rack to rest and cure; if later testing shows the deformation is within the allowable range, it can be used as normal. For components that have lain flat for more than 4 hours or are large in size, direct scrapping is recommended to avoid hidden risks during later installation. 2. Can GRG components be laid flat after full curing? Small components that are fully cured (rested for more than 72 hours after demolding) can lie flat for short periods. For large shaped components, upright storage is still recommended as the priority, since long-term stacking still carries a risk of stress deformation. 3. Do upright storage requirements differ for GRG components of different thicknesses? For components thicker than 30mm, support point spacing can be relaxed appropriately. For ultra-thin curved components thinner than 15mm, an extra flexible buffer layer should be added to the upright rack to prevent edge damage from bumps.