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SULFROCK

MAGNESIUM SULPHATE
BOARD PRODUCTS

A comprehensive range of MgS boards designed to meet the demands of modern construction

Whether you’re building, renovating, or manufacturing bespoke panel systems, our products deliver the strength, safety, and reliability required across residential, commercial, and industrial environments.

Our MgS boards are engineered for A1 fire performance, moisture resistance, dimensional stability, and long-term durability, making them a superior alternative to gypsum, fibre cement, plywood, and traditional MgO board formulations.

Below is an overview of our portfolio, where each product can be tailored to specific applications while maintaining SULFROCK’s stringent quality standards.

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SULFROCK

Magnesium Sulphate Board Products

A comprehensive range of MgS boards designed to meet the demands of modern construction

Get a Quote

MgSO₄ BENEFITS

Our magnesium sulphate boards (chlorine-free) are engineered to deliver exceptional fire resistance, moisture stability, and long-term durability. Suitable for residential, commercial, and industrial projects alike, MgS boards provide a reliable, sustainable, and high-performance solution for modern construction.

NON-COMBUSTIBLE

Magnesium sulphate board (MgS board) is a sustainable, non-flammable option for residential, commercial, and industrial construction. It resists fire for up to 2–3 hours, remains stable at 800°C, and will not ignite until around 1200°C.

WATER RESISTANT

SULFROCK MgS boards maintain their structural integrity even under moisture exposure. They resist warping, swelling, and delamination, ensuring long-term stability in humid or wet environments.

HEALTHY BY DESIGN

Our magnesium sulphate boards are free from fly ash, formaldehyde, crystalline silica, and other harmful substances – providing a cleaner, safer choice for modern construction.

TERMITE PROOF

SULFROCK’s moisture-stable, fire-safe and inorganic composition naturally prevents damage from pests, mould, and decay, delivering long-lasting durability in all climates.

ENVIRONMENTALLY FRIENDLY

Made from natural compounds, our boards are recyclable and landfill-safe, classified as “nutritional waste.” They also pass 36-month freeze / thaw testing, ensuring reliable year-round performance.

FUNGUS RESISTANT

With built-in antimicrobial properties, SULFROCK MgS boards resist mould, mildew, fungi, and rot. The chloride-free formulation eliminates risks of corrosion and material expansion.

NON-COMBUSTIBLE

Magnesium sulphate board (MgS board) is a sustainable, non-flammable option for residential, commercial, and industrial construction. It resists fire for up to 2–3 hours, remains stable at 800°C, and will not ignite until around 1200°C.

WATER RESISTANT

SULFROCK MgS boards maintain their structural integrity even under moisture exposure. They resist warping, swelling, and delamination, ensuring long-term stability in humid or wet environments.

HEALTHY BY DESIGN

Our magnesium sulphate boards are free from fly ash, formaldehyde, crystalline silica, and other harmful substances – providing a cleaner, safer choice for modern construction.

TERMITE PROOF

SULFROCK’s moisture-stable, fire-safe and inorganic composition naturally prevents damage from pests, mould, and decay, delivering long-lasting durability in all climates.

ENVIRONMENTALLY FRIENDLY

Made from natural compounds, our boards are recyclable and landfill-safe, classified as “nutritional waste.” They also pass 36-month freeze / thaw testing, ensuring reliable year-round performance.

FUNGUS RESISTANT

With built-in antimicrobial properties, SULFROCK MgS boards resist mould, mildew, fungi, and rot. The chloride-free formulation eliminates risks of corrosion and material expansion.

FEATURED PRODUCTS

With almost a decade spent specialising in chloride-free MgO boards, we are proud to offer exterior sheathing, interior wall boards, tile backers, underlayment, subfloor panels, partitions, and decorative wall panels.

COMPATIBILITY FOR CONSTRUCTION

Feature SULFROCK MgS Boards Solid Wood Board Composite Board Ceramic Sheet Magnesium Chloride Board (Cl2) Calcium Silicate Board
Environmentally Friendly High Average High Average Average High
Fireproof A1 B2 B1 A2 A2 A1
Waterproof High Poor Poor Poor Poor Average
Mould Resistent High Poor High High Poor High
Single Layer Subfloor ✓ ✓ ✓ ✓ ✓ ✓
Wear Resistant High Poor Poor High High Average
Weather Resistant High Poor Poor High Average High
Fastener Retention High High High Poor High Poor
Overview / Comments Highly Reliable Substrate Costly Poor Surface Finish Fragile & Costly Moisture Build-Up High Weight, Moisture Risk

PRODUCTS FOR EVERY APPLICATION

MgS Board Applications

Our magnesium sulphate (MgS) boards are versatile and engineered for a wide range of construction applications:

Exterior structural sheathing, interior wall boards, tile backer, underlayment, single-layer subfloors, partition walls, and decorative panels

Technical Specifications

  • Thickness: 3–20 mm

  • Size: 1220 × 2440 mm, 1220 × 2740 mm

  • Surface: Standard or sanded

  • Fireproof Grade: A1

  • Moisture Movement: 0.1–0.12%

  • Density: 1000–1100 kg/m³

  • Flexural Strength: 10–16 MPa

Custom Solutions

Every project is unique, that’s why SULFROCK offers tailored MgS board solutions to meet your exact requirements:

  • Custom sizes and thicknesses

  • Special surface treatments for enhanced moisture or acoustic performance

  • Pre-finished boards ready for painting, wallpaper, or decorative coatings

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MGS BOARDS FREQUENTLY ASKED QUESTIONS

We’ve compiled the answers to the most common questions about SULFROCK MgS boards to help you make informed construction decisions

What is MgS Board?

MgS board, also known as magnesium sulphate board, is a high-performance building material made from magnesium sulphate and selected additives. It delivers excellent strength, durability, fire resistance, and moisture resistance, making it suitable for a wide range of interior and exterior construction applications. Boards are available in multiple thicknesses and sizes for flexibility in domestic, commercial, and industrial projects.

What Are MgS Boards Used For?

MgS boards are highly versatile and suitable for:

  • Exterior Applications:
    Wall sheathing, subfloor, fascia, lap siding

  • Interior Applications: Wall panels, ceiling boards, tile backer, drop ceiling tiles, fire wall systems

  • Specialty Applications: Office cubicles, room dividers, structural insulated panels (SIPs)
Do MgS Boards Offer Fire Resistance?

Yes, SULFROCK MgS boards are Class A1 fire-rated, the highest level of fire protection. They are non-combustible and do not emit toxic smoke when exposed to fire, making them ideal for fire-rated walls, ceilings, and containment systems.

  • Withstand extreme heat up to 800°C (1,472°F)

  • Maintain structural integrity for several hours in direct flame

  • No harmful fumes, supporting safer evacuation during fire emergencies

Are MgS Boards Water-Resistant?

Yes, MgS boards are highly resistant to moisture:

  • Low Water Absorption: Prevents swelling, warping, or structural damage

  • Mold & Mildew Resistant: Inorganic composition discourages growth

  • No Delamination: Maintains integrity even when exposed to water

  • Compatible with Wet Areas: Suitable for tile backer applications in showers, pools, and bathrooms

Note: Boards are water-resistant but not fully waterproof – prolonged submersion may require additional protection.

Are MgS Boards Breathable?

Yes. MgS boards allow limited air and moisture vapor transfer, which helps prevent condensation and moisture build-up inside walls, supporting healthier indoor environments and applications in passive-house or historic renovations.

Are MgS Boards Sustainable?

Absolutely. SULFROCK MgS boards are eco-friendly, thanks to:

  • Natural Raw Materials: Made primarily from magnesium sulphate and mineral fillers

  • Low Carbon Footprint: Less energy-intensive production than gypsum or cement boards

  • Durable & Long-Lasting: Resistant to moisture, mold, and pests

  • Recyclable & Non-Toxic: No VOCs or formaldehyde emissions

  • Energy-Efficient: Provides thermal insulation to reduce energy use

How Do MgS Boards Compare to Gypsum Boards?

Advantages of MgS boards:

  • Water Resistance: 0.34% absorption vs 3% for gypsum

  • Fire Resistance: Class A1 with less thickness

  • Density: 0.85–1.2 g/cm³ (lighter than gypsum)

  • Impact Strength: ≥4.5 kJ vs 1 kJ for gypsum

  • Bending Strength: 18–27 MPa vs ≤5.6 MPa for gypsum

  • Environmental Impact: Lower energy production, recyclable, no toxic fumes

How Do MgS Boards Compare to Calcium Silicate Boards?

MgS Boards:

  • Density: 0.85–1.2 g/cm³, lightweight and easy to handle

  • Water Resistance: Excellent (0.34% absorption)

  • Fire Resistance: Non-combustible, high heat stability

  • Impact Strength: ≥4.5 kJ

  • Bending Strength: 18–27 MPa

  • Durability: Moisture-resistant, strong, lightweight

Calcium Silicate Boards:

  • Density: 1.2–1.3 g/cm³, heavier

  • Water Resistance: Moderate (≈3% absorption)

  • Fire Resistance: Non-combustible, slightly lower rating

  • Impact Strength: ~1 kJ

  • Bending Strength: ≤5.6 MPa

  • Durability: Strong, but heavier and less moisture-resistant

Conclusion:
MgS boards are lightweight, fire and water resistant, and highly durable, ideal for interior and exterior applications. Calcium silicate boards are heavier and slightly less moisture-resistant but offer flexibility in design applications.

Conclusion: MgS boards are lightweight, fire- and water-resistant, and highly durable, making them ideal for both interior and exterior applications. Calcium silicate boards are heavier and slightly less moisture-resistant, but still suitable for structural or decorative applications where flexibility is required.

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We’ll help you find the ideal solution for your next project.

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