First, how is it made?
A composite material known as fiber cement board is formed from non-reinforcing fibers, cement, units of fine (silica) sand, and various additives. Fiber cement boards are wet-pulped, shaped using a mold, and cured under high pressure to produce the end product.You can visualize fiber cement board as being a mini form of reinforced concrete-wherein the fibers perform like a skeleton for added toughness and the cement/sand perform as a body providing the fiber cement board with added strength and hardness.This creates a naturally strong base.
Let's start with its "core strength": flexural strength
Many people assume that cement-based products are brittle and prone to breaking. However, fiber cement board is quite the opposite. Its flexural strength-simply put, how much it can bend before breaking-generally reaches 15–25 MPa or higher.
What does this mean? You can easily crack a regular plasterboard with a slight bend, but a fiber cement board of the same thickness requires considerable force and significant deformation before it breaks. This toughness allows it to withstand wind pressure, minor structural movement, and even in earthquake-prone areas, it can "overcome rigidity with flexibility" without cracking.
Stability: impact resistance
Imagine a tool accidentally striking a wall during construction, or hail hitting an exterior surface. In these situations, the advantages of fiber cement board become clear. Unlike ceramic tiles, which can chip easily, or some thin boards that can be punctured, fiber cement board benefits from its fiber-reinforced structure, which effectively disperses impact forces.
Localized damage is common to this type of material when subjected to high impacts; such localized damage will happen rather than major breakage, and this is vital to ensure safety over a long period of time, and help to keep costs down for maintenance.
Environmental durability can be measured by several different criteria, including freeze-thaw and weather resistant properties.
Freeze-thaw resistance has a larger significance to materials in non-manufactured conditions (such as outside). In addition, all materials must be able to endure the shear amount of freezing and thawing, especially in part because the temperature can fluctuate drastically throughout the days & nights.
With high-pressure curing, fiber-cement board has a much lower porosity than regular cement board, meaning it does not absorb moisture as quickly. The low temperatures (from -20° to 30° Celsius) will not cause cracks to develop or damage the fiber cement board as would happen with ordinary masonry bricks. Tests showed minimal strength loss after undergoing a series of dozens of freeze/thaw cycles.
Also, because fiber cement board is made from nonorganic materials, it does not degrade from either water (like rain) or UV light (like sunlight). After 20 to 30 years of being exposed to both the elements of water and UV light, the physical characteristics of fiber cement board will remain approximately the same as they did when first manufactured.
Safety performance: fire and moisture resistance
Asbestos-free fiber cement siding is a Class A non-combustible material. Fiber cement siding will not combust or produce toxic gases when exposed to extremely high temperatures; it essentially only transfers heat. This makes fiber cement siding an effective fire protection system for any fiber cement siding project that requires a high level of fire resistance.
In addition to being able to resist moisture damage, fiber cement siding is also very good at resisting moisture damage. Fiber cement siding will not allow mildew growth or shrinkage from excess moisture, and fiber cement siding will remain stable dimensionally even under high humidity conditions in areas with a high moisture content, such as bathrooms and basements.
