HocreBoard Fiber Cement Products -Company Blog

When comparing Fiber Cement and MgO Sulfate (MOS) Board for facades, the choice often comes down to a trade-up between proven aesthetic durability (Fiber Cement) and superior technical safety/handling (MgO Sulfate)

While both are non-combustible alternatives to wood or plastic, they behave very differently in real-world exterior conditions.

Technical Comparison Table

MgO Sulfate Board is highly recommended for high-humidity areas. In fact, its superior performance in moisture-prone environments is the main reason architects and builders choose it over the cheaper Chloride-based MgO boards.

Here is why it excels in humid conditions:

1. Zero “Sweating” (Non-Hygroscopic)

The most critical advantage is that Magnesium Sulfate (MgSO4) does not attract moisture from the air.

• Chloride boards are “hygroscopic,” meaning they pull water vapor out of the air. In high humidity, this causes “weeping”—salty water droplets forming on ...

MgO Sulfate board (Magnesium Oxysulfate / MOS) is considered a “second-generation” advancement over the traditional Chloride MgO board (Magnesium Oxychloride / MOC).

The primary reason it is “better” is that it solves the two most significant failures of the original technology: metal corrosion and “sweating” (leaching).

1. No “Sweating” or Leaching (Non-Hygroscopic)

Traditional Chloride boards use Magnesium Chloride (MgCl2), which is highly hygroscopic—meaning it naturally attracts moisture from the air.

• The Problem: In humid environments, Chloride boards absorb so much water that droplets ...

The primary reason engineers and architects switch from standard MgO boards to MgO Sulfate Boards is specifically to eliminate the “sweating” (hygroscopic) and “leaching” (efflorescence) issues.

Here is the technical breakdown of why MgO Sulfate boards perform differently in high-humidity environments.

The Chemistry: Why it doesn’t “Sweat”

To understand why Sulfate boards don’t sweat, you have to look at what causes the problem in older versions:

• Standard MgO (Chloride-based): Uses Magnesium Chloride (MgCl2).This salt is hygroscopic, meaning it naturally attracts water molecules from ...

In many international markets, especially in Australia, New Zealand, and the UK, the terms Fiber Cement Plank and Weatherboard are used interchangeably. However, “Weatherboard” specifically refers to the style of installation where boards overlap to shed water.

Here is a breakdown of the key English terminology and technical details specifically for Fiber Cement Weatherboards.

1. Style & Profile Keywords

When discussing weatherboards, the “profile” (the shape of the edge) determines how they look on the wall:¹

• Lap Siding / Traditional Lap: The ...

Fiber cement planks are renowned for their exceptional dimensional stability, meaning they are far less likely to crack or warp compared to wood or vinyl. However, like all building materials, they do undergo slight physical changes.

The key to their durability is that fiber cement is “Engineered for Climate.” Here is a detailed breakdown of how it handles thermal expansion:

1. Minimal Thermal Expansion (vs. Other Materials)

Fiber cement has a very low Coefficient of Thermal Expansion (COTE). Because it is a ...

Fiber cement planks are specifically engineered to be “climate-resilient,” meaning they outperform traditional materials like wood or vinyl in extreme environments. Because they are composed of an inorganic blend of Portland cement, sand, and cellulose fibers, they do not behave like organic materials when exposed to the elements.

1. Performance in High UV (Intense Sunlight)

In regions with blistering sun, UV radiation is the primary cause of material “fatigue.” Fiber cement handles this through its unique chemical makeup:

• Dimensional Stability: Unlike vinyl, ...

UV-coated fiber cement boards are specifically engineered for exterior facades. In fact, exterior cladding is one of their most common and high-performing applications.

While standard fiber cement is durable, the addition of a UV-cured layer transforms it into a premium facade solution that addresses the three biggest challenges of exterior walls: sun damage, water ingress, and pollution

1. Performance in Harsh Weather

Exterior facades are subject to constant thermal cycling (the expansion and contraction from day to night).

• Dimensional Stability: Because the board ...

UV-coated high-density fiber cement (HDFC) boards are widely regarded as some of the safest decorative building materials available. Their fire performance is a result of a non-combustible core protected by a thin, high-performance polymer film.

In terms of international fire safety standards, these boards typically achieve the highest possible ratings for “Reaction to Fire.”

1. Fire Classification (Class A1 / A2)

Most UV-coated HDFC boards are classified under the European standard EN 13501-1 or the American ASTM E84.

• Class A1 / A2 (Euroclass): ...

The main benefit of a UV coating on High-Density Fiber Cement (HDFC) boards is the instant creation of a “hyper-durable” surface shield that standard air-dried paints cannot achieve.

While HDFC provides the structural strength, the UV coating provides the functional performance. Here is a breakdown of the specific advantages:

1. Superior Surface Hardness (Anti-Scratch)

The UV-curing process uses high-intensity ultraviolet light to trigger a rapid chemical reaction (polymerization). This creates a rock-hard finish that is significantly more resistant to scratches and abrasions.

• Pencil ...