GRG vs Fiberglass FRP: Which Has Better Fire Performance and Eco-Friendliness?

GRG and FRP (fiberglass reinforced plastic) are two types of building materials widely used in the field of free-form decoration. Many project contractors struggle with the performance differences between the two when selecting materials—especially the fire performance and environmental attributes that are of greatest concern, as these directly affect the safety and compliance of indoor and outdoor project implementation. Drawing on nearly 30 years of hands-on experience in free-form architectural engineering, this article provides an objective comparison of the core characteristics of the two materials, offering practical and actionable reference for project material selection.

### I. Basic Property Differences: Core Positioning of the Two Materials Many people tend to confuse the application scenarios of GRG and FRP. Essentially, the two materials have clear boundaries in terms of raw material base and suitable scenarios: GRG, short for Glass Fiber Reinforced Gypsum, uses modified gypsum as its base material, and its core application scenarios focus on interior decoration, such as the curved ceilings of theaters and exhibition venues and the curved artistic shapes of commercial complexes, with the emphasis on achieving seamless, smooth interior forms. FRP, commonly known as fiberglass, uses synthetic resin as the matrix and glass fiber as the reinforcing material, and its core applications are lightweight large outdoor landscape sculptures and large-span non-standard facade decorations, with the emphasis on outdoor weather resistance and lightweight performance of large-size components. There is no absolute superiority or inferiority between the two; the key is to match the project's scenario requirements. Currently, the industry also has many mixed projects that use both materials—for example, the combination scheme of using GRG for interior shapes and FRP for outdoor supporting sculptures in large cultural and tourism venues—which already has very mature implementation experience.

### II. Fire Performance Comparison: Safety Performance of the Two Materials Fire protection is a core mandatory indicator for material selection in public building projects. According to public data from national building material testing, the main component of GRG is inorganic gypsum, which is inherently a non-combustible material. Under national standard testing, its combustion performance can meet Class A non-combustible requirements; it does not produce toxic smoke in a fire and does not melt or drip at high temperatures, fully meeting the fire protection requirements of crowded indoor venues and commercial spaces. The fire performance of FRP, on the other hand, depends on the resin matrix used: standard FRP is typically Class B combustible and releases small amounts of irritating smoke at high temperatures, and even flame-retardant modified special FRP can at best reach the Class B1 fire-retardant standard, which cannot meet the Class A fire protection requirements for indoor public buildings. It should be particularly noted that some merchants' current claims that “FRP achieves Class A fire resistance” do not comply with the current national standard testing specifications; when selecting materials, project parties may require the other party to provide test reports from authoritative third-party institutions for verification, so as to avoid the risk of failing fire acceptance inspection.

### III. Environmental Comparison: Full Life-Cycle Performance in Production and Use The environmental comparison can be viewed from two dimensions: the production side and the use side. On the production side, GRG's raw material is mainly natural gypsum ore; no volatile organic solvents are added during production, and its discharge of waste gas, wastewater, and solid waste is far lower than that of resin-based materials, resulting in less environmental pressure in the production stage. FRP production, however, requires large amounts of liquid resin raw materials, and a small amount of volatile organic compounds is emitted during the curing process, placing higher demands on the environmental treatment capacity of the production plant. On the use side, GRG finished products are odorless and non-radioactive, meet the environmental testing standards for interior decoration, and can be put into use immediately after installation without long-term release of harmful substances. Qualified eco-friendly FRP finished products do not release harmful substances under normal room-temperature conditions, but FRP made from inferior resin may release slight odors in high summer heat and strong sun exposure, so it is more suitable for outdoor scenarios and not recommended for direct use in enclosed indoor spaces.

### IV. Practical Reference Suggestions for Material Selection Based on the characteristics of the two materials, project parties can quickly make a selection decision according to the scenario: for crowded indoor decoration projects such as theaters, exhibition halls, and commercial complexes, GRG is the preferred material, as it not only meets the mandatory Class A fire protection requirements but also achieves higher precision for curved shapes; for outdoor large landscape sculptures and large-span free-form facade projects, FRP is preferred, as its lightweight and high-strength properties can reduce the load pressure on the building structure, and its outdoor weather resistance is better suited to open-air environments. In addition, note that the mold-based production of both materials places high demands on the factory's detailed design capabilities; it is recommended to cooperate with service providers with implementation experience in nearly a hundred similar projects to avoid problems such as insufficient shape fidelity and construction delays.

#### Common Questions (FAQ) 1. Can GRG replace FRP for outdoor decoration? Not recommended. GRG has relatively weak water and weather resistance; long-term exposure to outdoor rain and sun easily leads to surface powdering and deformation. Outdoor scenarios are better suited to the material properties of FRP fiberglass. 2. Can flame-retardant FRP be used indoors? For crowded indoor public building projects where the fire protection requirement is Class A, even Class B1 flame-retardant FRP does not meet the regulatory requirements and can only be used in ordinary indoor supporting scenarios that are not crowded, and the fire acceptance standards must be confirmed in advance. 3. Is there a big difference in construction period between GRG and FRP? Both materials are prefabricated components installed on site, and the delivery cycles for standard components are basically the same; the delivery cycle for conventional projects is usually around 7-15 days. The core difference lies in the detailed design difficulty of complex curved shapes, which is not strongly related to the materials themselves.