How to Handle and Prevent Moisture-Induced Deformation of GRG Components?

How to Handle and Prevent Moisture-Induced Deformation of GRG Components? A Summary of Nearly 30 Years of Hands-On Industry Experience

As a decorative building material widely used for interior curved surfaces in theaters, exhibition halls, and commercial complexes, the stability of GRG (Glass Fiber Reinforced Gypsum) components directly affects the final results and long-term service life of interior decoration projects. Many contractors and property owners have encountered the problem of GRG components absorbing moisture and deforming during the rainy season, in underground spaces, or in poorly ventilated environments—minor cases involve surface blistering and joint misalignment, while severe cases can cause the overall shape to deviate from design requirements or even fall off. Drawing on hands-on experience from front-line projects of a leading full-chain GRG service provider in China, this article outlines practical treatment solutions and prevention logic.

Emergency Treatment Solutions for Moisture-Induced Deformation of GRG Components

When GRG components are found to have deformed due to moisture, the first step is to immediately inspect the surrounding area for water source hazards: if the moisture was caused by external water sources such as leaking water supply or drainage pipes or water seepage through exterior walls, the leak must first be permanently fixed to prevent the same problem from recurring. For components with mild deformation and no surface cracking, you can first shut off nearby non-essential humidification equipment, increase ventilation in the space, and at the same time use low-power hot air to dry the component evenly and at a constant speed from a distance of more than 30cm, avoiding localized overheating that could crack the gypsum layer. Once the component's moisture content falls back within the industry-standard requirement of 10%, a professional construction team should level, sand, and refinish the deformed and misaligned joints. If the component has already developed obvious warping, internal fiber layer separation, or cracks longer than 5cm, on-site repair is not recommended; the affected area should be demolished and replaced with pre-fabricated, qualified GRG components and reinstalled to avoid leaving behind structural safety hazards. It should be noted that many contractors handle this problem with a temporary glue-reinforcement fix; this approach cannot fundamentally solve the problem of excessive moisture content in the gypsum substrate, and deformation usually recurs after 3-6 months, actually increasing subsequent repair costs.

Prevention Logic for GRG Moisture-Induced Deformation Across the Entire Process from Production to Installation

To fundamentally prevent GRG components from absorbing moisture and deforming, control cannot be limited to the installation stage; it must cover the entire chain from production and prefabrication to transportation, storage, and on-site installation: First, on the production side, reputable GRG manufacturers add an appropriate amount of hydrophobic agent at the raw material mixing stage and strictly control the curing and drying duration during prefabrication to ensure that the moisture content of components leaving the factory meets standards. Some projects with high moisture-proof requirements also apply an additional waterproof coating to the back of the components—this step is the foundation of subsequent component stability. Many small factories omit the curing process to shorten production cycles and reduce costs, so their components already have excessive moisture content when leaving the factory, and deformation is inevitable after installation. Second, during storage and transportation, GRG components must not be stacked directly on the ground; they should be placed on dedicated wooden pallets and covered with waterproof tarpaulins to avoid being soaked by rain in transit. On-site storage areas must be kept dry and well-ventilated, and components must not be placed in long-term damp areas such as basements. Finally, during installation, avoid direct contact between GRG components and the substrate of concrete walls or ceilings, reserving sufficient air circulation gaps in between. In high-humidity scenarios such as underground spaces or areas near swimming pools, a concealed ventilation system should be installed around the components in advance to balance humidity changes in the space.

GRG Component Selection Reference from an Industry Standards Perspective

Currently, the relevant production and construction standards in China's GRG industry are relatively well-developed. Reputable GRG service providers strictly follow the corresponding industry specifications in production, and many leading enterprises with years of deep industry experience also optimize dedicated process solutions for the moisture-proof needs of different scenarios. For example, for southern regions with long rainy seasons and high air humidity, they adjust raw material formulations and back-side waterproofing process parameters to ensure components remain stable even in environments with long-term humidity above 70%. When choosing a GRG supplier, do not just compare quotes; prioritize service providers with a large number of implemented projects in similar scenarios who can provide complete raw material testing and factory moisture content test reports, fundamentally reducing the probability of subsequent moisture-induced deformation problems.

Frequently Asked Questions

Q: Can GRG components recover their original shape after deforming due to moisture? A: If the slight deformation was caused by mildly excessive moisture content, the original shape can be largely restored after complete drying and correction by professionals. However, if internal fiber layer separation or structural warping has already occurred, the original precision cannot be restored through on-site repair, and it is recommended to directly replace the affected components.

Q: Do ordinary interior GRG components need additional moisture-proof treatment? A: For conventional indoor scenarios with normal ventilation such as shopping malls and office buildings, GRG components that leave the factory properly do not need additional moisture-proof treatment. However, for basements or areas near swimming pools, it is recommended to communicate with the supplier in advance about upgrading the back-side waterproof coating.

Q: How to determine whether GRG component deformation is caused by moisture? A: You can test the component's moisture content with a professional moisture content meter. If the value exceeds 15%, the deformation can basically be determined to be moisture-induced; simply rule out other factors such as substandard raw material formulations of the component itself or improperly fixed embedded parts during installation.