How Terracotta Panels Are Made: A Complete Guide to Exterior Dry-Hanging Terracotta Production Process

In the world of sustainable architecture, exterior dry-hanging terracotta panels (often called terracotta cladding panels) have become a top choice for architects, builders, and designers. Loved for their natural texture, durability, and eco-friendly properties, these panels transform raw clay into elegant, weather-resistant building facades that stand the test of time. If you’re curious about terracotta panel manufacturing or looking to understand the process behind this popular building material, you’ve come to the right place. Today, we’re breaking down the 6 core steps that turn natural clay into high-quality exterior dry-hanging terracotta panels—from raw material selection to final packaging.

Terracotta panels are crafted entirely from natural clay, with no harmful additives, making them a sustainable and eco-conscious option for modern buildings. Unlike synthetic cladding materials, terracotta’s production process honors traditional ceramic craftsmanship while integrating modern automation, ensuring consistency, strength, and aesthetic appeal. Let’s dive into each step in detail.

Step 1: Raw Material Preparation (The Foundation of Quality)

The quality of terracotta panels starts with the raw materials—this step is non-negotiable for creating durable, consistent cladding. Here’s how manufacturers get the clay ready:

• Material Selection: The main raw materials are kaolin, clay, and shale, which provide the panel’s base strength and texture. To adjust performance (like durability and workability), quartz and feldspar are added in precise proportions

• Crushing and Screening: The raw materials are crushed into particles smaller than 5mm, then sieved to remove impurities like stones or debris—this ensures the clay mixture is smooth and uniform

• Batching and Mixing: The crushed materials are mixed according to a strict formula, and water is added to reach a moisture content of 20%–25%. This creates a workable clay paste that’s ready for shaping

• Ageing (Pugging Rest): The clay paste is sealed and left to rest for 24–48 hours. This process, called ageing, improves the clay’s plasticity, making it easier to shape and less likely to crack during later steps

• Vacuum Pugging: The aged clay is put through a vacuum pug mill to remove air bubbles. This step makes the clay denser and more uniform, preventing defects in the final panel.

• The clay paste is fed into a vacuum extruder, which forces it through a mold at high pressure to form continuous strips. These strips can be single-layer or double-layer hollow, depending on the design requirements.

• An automatic cutting machine trims the continuous strips to the desired length, creating wet blanks (unfired panels).

• Each wet blank is inspected for appearance, size, and density to catch any defects early—this ensures only high-quality blanks move to the next step.

Step 3: Drying (The Crack-Prevention Challenge)

Drying is one of the most delicate steps in terracotta panel production. If the wet blanks dry too quickly or unevenly, they’ll crack—ruining the entire panel. Manufacturers use precise temperature and humidity control to avoid this

• Drying Method: Most factories use chamber dryers or multi-layer roller kilns, which allow for controlled temperature and humidity .

• Drying Regime: The blanks are dried slowly in a low-temperature, high-humidity environment. This gradual drying process prevents rapid moisture loss, which causes cracking.

• Drying Endpoint: The process continues until the moisture content of the blanks drops to below 2%–3%. At this point, the blanks are dry and stable enough for high-temperature firing .

Step 4: High-Temperature Firing (The Core of Durability)

Firing is what transforms soft, dry clay blanks into hard, durable terracotta panels. This step is where the clay undergoes chemical and physical changes, becoming resistant to weather, moisture, and wear. Here’s how it works:

• Kiln Loading: The dry blanks are carefully stacked on kiln cars with uniform spacing to ensure even heating during firing.

• Firing Process: The blanks are fired in a tunnel kiln or roller kiln (continuous, automated systems) at around 1200°C for 24–48 hours. The firing process has four key stages:

a. Low Temperature (0–400°C): Residual moisture in the blanks is removed.

b. Medium Temperature (400–900°C): Organic matter in the clay decomposes, and oxidation occurs.

c. High Temperature (900–1200°C): The clay sinters, and mullite (a hard, durable mineral) forms—this gives the panels their strength and weather resistance

d. Slow Cooling: The panels cool down with the kiln to below 100°C. Slow cooling prevents thermal shock, which can cause cracking

Step 5: Finishing and Surface Treatment

After firing, the terracotta panels are to meet exact design specifications and enhance their aesthetic appeal. This step allows for customization, making terracotta panels suitable for a wide range of architectural styles

• Cutting and Edging: The fired panels are precision-cut and edged to refine their size, add chamfers, or create grooves (for dry-hanging installation).

• Surface Treatment: A variety of surface finishes are available to match different design visions, including natural finish, sand finish, grooved finish, glazed finish, and matte finish. Each finish adds a unique texture and appearance to the panels.

Step 6: Quality Inspection and Packaging

The final step ensures that only the highest-quality terracotta panels reach the market. Every panel undergoes strict quality control to meet industry standards.

• Full Inspection: Each panel is inspected for size, flatness, color difference, cracks, chips, and strength. Any panel that fails the inspection is rejected.

• Packaging and Storage: Qualified panels are wrapped in film, packed securely, and stored in warehouses. This protects the panels during transportation and ensures they arrive in perfect condition for installation.