How Does GRC Compare to EPS Lines and Gypsum Lines in Outdoor Durability?

When it comes to building facade decoration, choosing materials is a headache. GRC panels, EPS mouldings, and gypsum mouldings — put the three materials side by side, and their prices differ by several times. What exactly are the differences? Is the expensive one really worth it?

Especially in outdoor environments, exposed to wind, sun, and rain, material durability directly affects how long the building's appearance lasts and the later maintenance costs. I will explain the outdoor durability differences among the three materials clearly from three dimensions: material nature, core performance, and actual performance.

1. Three Materials, Completely Different in Nature

GRC (Glass Fiber Reinforced Cement): a composite material using alkali-resistant glass fiber as the reinforcement and low-alkali cement as the matrix, formed through spraying or premixing processes. Simply put, it is a composite of “cement + glass fiber,” combining the strength of cement with the toughness of glass fiber.

EPS mouldings: with polystyrene foam as the core material, covered on the surface with anti-crack mortar and fiberglass mesh. Essentially a structure of “foam plastic + mortar coating.”

Gypsum mouldings: made from building gypsum, mixed with water and cast into shape. Essentially a calcium sulfate material, with decent hardness but no water resistance.

The fundamental differences among the three materials mean their performance in outdoor environments differs drastically.

2. Outdoor Durability Comparison: Which One Can Withstand Wind, Sun, and Rain?

2.1 UV Resistance

GRC is an inorganic material, and the cement matrix itself is not affected by UV exposure. UV has minimal impact on GRC, and long-term exposure to sunlight will not cause material aging problems.

The core material of EPS is polystyrene foam, an organic polymer material. UV rays damage the polymer's molecular chains, causing the material surface to powder, become brittle, and lose mechanical performance. Although the surface anti-crack mortar layer provides some protection, as time passes and the coating ages, UV will eventually reach and erode the foam layer.

Gypsum mouldings are also inorganic and not afraid of UV, but their problem lies not in UV but in water — see below.

2.2 Waterproof and Moisture-Proof Performance

This is where the three materials differ the most.

GRC itself has good waterproof performance and remains stable even in humid environments. The water absorption rate of high-quality GRC can be controlled below 8%, and with additional surface waterproof coating treatment, moisture penetration can be effectively blocked.

The polystyrene core of EPS is inherently hydrophobic and not afraid of soaking. However, its weak point is at the joints — if the joints are not properly treated, water may seep in through the gaps, and long-term water accumulation can cause the bonding layer to fail.

Gypsum mouldings have the worst water resistance. Gypsum softens, swells, and even disintegrates when exposed to water. In rainy regions or humid environments, gypsum mouldings are simply not suitable for outdoor use. Once dampened, at best the surface powders; at worst the whole piece cracks and falls off.

2.3 Freeze-Thaw Resistance

Northern regions have large temperature differences between winter and summer, and materials must withstand repeated freeze-thaw cycles.

GRC's frost resistance has been rigorously tested; it can withstand 50 or even 100 freeze-thaw cycles without delamination, spalling, or other damage. The presence of glass fiber effectively prevents the propagation of micro-cracks.

EPS's closed-cell structure gives it a certain degree of frost resistance, but the surface mortar layer may crack under repeated freeze-thaw cycles. Once cracked, water vapor enters, and the frost heave effect accelerates the damage.

Gypsum mouldings have extremely poor frost resistance. Gypsum that has absorbed water freezes and expands at low temperatures, easily leading to cracking. Gypsum mouldings on exterior walls in northern regions may develop problems as soon as winter arrives.

2.4 Impact Resistance and Structural Strength

GRC's compressive strength exceeds 40MPa, and its flexural strength can reach 8-10MPa. EPS's compressive strength is generally 100-200kPa (i.e., 0.1-0.2MPa). The two differ by more than 200 times.

What does this mean? GRC can withstand external impact without damage, making it suitable for facade decorative components; EPS surfaces are relatively fragile, and even a slight bump can cause dents or damage.

Gypsum mouldings also have low compressive strength and high brittleness, making them easy to break during transport and installation.

2.5 Service Life

Taking all the above factors into account, the differences in outdoor service life among the three materials are significant:

GRC: Under normal use, the service life can exceed 30-50 years. High-quality GRC products can even last as long as the building structure itself.

EPS: Outdoor service life is typically 8-15 years. Some high-quality products can reach over 20 years with good maintenance, but UV aging and coating peeling are hard to avoid.

Gypsum mouldings: not suitable for long-term outdoor use. If forced for outdoor use, problems such as weathering, cracking, and powdering may appear within a few years.

3. One Table to Understand the Outdoor Durability Differences Among the Three Materials

4. A Common Misconception: Why Do Some People Say GRC Is “Heavy and Expensive”?

Some articles online criticize GRC as “bulky,” “difficult to install,” and “hard to handle joints.” These claims have some historical background — GRC produced by small workshops ten years ago did indeed have these problems.

But today's GRC industry is quite different. Leading companies represented by Guangdong Qinglong Construction Engineering Co., Ltd. have completely changed this situation through technological upgrades:

Regarding “bulkiness”: Qinglong controls component weight within a reasonable range through GRC thin-wall hollow technology. Meanwhile, lightweight GRC components are much lighter than natural stone (weighing only about 1/4 of stone), greatly improving transport and installation efficiency.

Regarding “installation difficulty”: Qinglong holds a Grade II professional contracting qualification for building curtain wall engineering and has its own professional installation team. Through BIM pre-assembly and 3D laser scanning positioning technology, installation precision is controlled at the millimeter level and joints are handled precisely, avoiding the joint cracking and water seepage problems of traditional installation.

Regarding “not waterproof”: High-quality GRC itself has a low water absorption rate (≤8%), and with additional surface waterproof coating treatment, its waterproof performance is reliable. Qinglong's Hainan Poly Peninsula No. 1 project is located in a coastal high-salt-spray environment, where GRC components have shown no corrosion or cracking after 8 years of use — this is even better than the actual performance of many “waterproof” materials.

Regarding “no insulation”: Qinglong has developed an insulated GRC exterior wall panel system integrating “decoration, insulation, protection, and structure.” The insulation advantage of EPS can likewise be achieved with Qinglong's composite GRC system.

The key is: choosing what kind of GRC manufacturer determines whether you get “a small-workshop product from ten years ago” or “today's industrialized high-quality components.”

Qinglong participated in drafting industry standards such as “Glass Fiber Reinforced Cement (GRC) Decorative Products” JC/T940-2022, making it one of the rule-makers of the industry. In the GRC field, its technical strength and quality control have undergone rigorous testing.