MgO Board vs Fiber Cement Board: Which Performs Better in 2025?

MgO boards have caught the construction industry's attention because they can withstand extreme temperatures up to 1200°C. This remarkable heat resistance sets them apart from traditional fiber cement boards in many ways.

Fiber cement boards contain cement, sand, and cellulose fibers, but magnesium boards take a different approach. The new sulfate MgO boards combine magnesium oxide, magnesium sulfate, and other raw materials. The result is a lighter, more flexible product that resists impact better than its alternatives. Traditional fiber cement board remains popular in construction projects, though it contains silica that could be dangerous if workers inhale its dust.

These materials play vital roles in modern construction, yet their performance differs in several ways. MgO boards excel with their environmental advantages and leave a smaller carbon footprint thanks to natural materials and cleaner production methods. They also naturally fight off mold growth, which makes them perfect for humid spaces.

This piece explores the essential differences between these two building materials and helps you pick the right option to meet your specific needs in 2025 and beyond.

Material Composition and Manufacturing

Building materials' performance depends on what goes into them. Each board type behaves differently because of its unique ingredients and how they work together.

Fiber Cement Board: Cement, Sand, and Cellulose Fibers

Fiber cement boards combine several key components that create a tough construction material. Portland cement serves as the main binding agent and gives these boards their structural strength. The cement helps the boards stand up to environmental stress and makes them last longer.

Sand (crystalline silica) works as a filler that makes the boards stronger and denser. This ingredient keeps the boards stable and stops them from warping or shrinking as time passes.

The most crucial ingredient might be cellulose fibers, which come from recycled paper products. These plant-based fibers make the cement matrix more flexible and stronger. Using recycled cellulose makes fiber cement products more environmentally friendly.

The boards come to life through several crucial steps. The process starts when manufacturers blend cement, cellulose fibers, silica, and water into a smooth slurry. This mix gets poured onto flat surfaces or through special machines to create sheets of the same thickness. The boards then cure in high heat and humidity to build strength. The final step sees manufacturers cutting these boards to size and adding finishes as needed.

MgO Board: Magnesium Oxide, Perlite, and Fiberglass Mesh

MgO boards are quite different from fiber cement. These boards use magnesium oxide powder (MgO) as their main ingredient, making up 56-58% of the board. This natural mineral goes through high-temperature heating before becoming the primary cement-like component.

Magnesium sulfate or magnesium chloride (27-29%) binds everything together. These salts react with MgO powder and water to create a solid, rock-like structure.

The boards get extra properties from several other ingredients:

·       Perlite (3-4%): This expanded volcanic glass adds insulation and cuts weight

·       Wood fiber/sawdust (5-6%): Makes the board easier to work with and more stable

·       Fiberglass mesh (4-6%): Adds strength and makes the board more impact-resistant

·       Phosphate (0.1-0.3%): Makes chemical bonding happen faster

Production Process: High-Pressure vs Moisture-Curing

These materials take different paths to become finished products, which explains why they perform differently.

Fiber cement boards need high pressure to take shape. Manufacturers squeeze out extra water and get the right thickness by applying intense pressure. Some boards also go through autoclaving—a special high-pressure steam treatment that makes them even stronger.

MgO boards take a different route through moisture-curing. Manufacturers carefully measure and mix raw materials, then layer non-woven fabric and fiberglass mesh while pouring the mixture. The boards cure in two phases: first under controlled temperature and humidity, then at room temperature for up to seven days. Chemical reactions inside the board make it stronger during this time.

Fire and Moisture Resistance

Building materials show their true worth in extreme conditions. A construction board's resistance properties shape its durability, safety, and where you can use it best.

Fire Rating: 750°C vs 1200°C Tolerance

Fire resistance shows how well materials keep their mechanical properties when exposed to flames. This vital safety feature measures how long materials stay structurally sound in fires.

Magnesium boards handle heat amazingly well and can take temperatures up to 1200°C without breaking down much. These boards beat traditional building materials by a lot. Yes, it is true that MgO boards can last up to 4 hours in specialized systems, which gives people more time to escape during emergencies.

Fiber cement boards provide good fire protection, but not as much. These boards last between 1-2 hours, making them good enough for many uses but less reliable in extreme heat. Tests show they handle temperatures around 750°C before losing their structural strength.

The materials' makeup explains this difference. Magnesium oxide naturally won't burn, while cellulose fibers break down in extreme heat. MgO boards also don't spread flames and make very little smoke, which helps people escape more safely.

Water Resistance: Moisture-Resistant vs Fully Waterproof

Neither material completely stops water, but they handle it differently.

Fiber cement boards fight moisture well but aren't waterproof. Rain, splashes, and humidity won't warp or damage them. In spite of that, they might soak up some moisture over time without proper sealing, which can cause problems later.

Magnesium boards protect better against moisture. They stay strong even after long exposure to water and resist swelling and warping that damage other building materials. MgO boards made with magnesium sulfate work better in wet places than those with magnesium chloride because sulfate doesn't pull moisture from the air.

Both materials work great in wet areas like bathrooms and kitchens where regular drywall fails quickly. Magnesium boards just last longer in damp places without extra treatment.

Mold and Mildew Resistance: Limited vs Natural Resistance

Mold creates health and structural risks in buildings, especially in humid places.

Magnesium boards naturally fight mold because they're inorganic. Mold needs organic material to grow, so MgO boards stop fungal growth without extra treatments. This makes them perfect for bathrooms, basements, and coastal areas with high humidity.

Fiber cement boards resist mold somewhat but lack magnesium products' natural protection. They handle moisture better than wood products, but mold can still grow under certain conditions without proper care. Their cellulose fibers can feed fungi if moisture gets in.

Magnesium boards clearly work better than cement ones for long-term use in humid places. They need less maintenance and fewer protective coatings to stay mold-free throughout their life.

These materials' resistance properties affect where you can use them, how much maintenance they need, and their lifetime costs in different environments.

Durability and Structural Strength

Structural integrity is a vital factor in choosing construction materials that need to last. MgO board and fiber cement board each have unique performance features that affect how long they last in different settings.

Impact Resistance: Brittle vs High Impact Strength

Fiber cement boards act like typical brittle materials—they break under stress without much warning. This makes them weak against sudden impacts. They don't handle vibration and impact loads well, even though they're strong under compression. These boards might crack or shatter when hit hard instead of absorbing the force.

MgO boards, on the other hand, handle impacts much better because of how they're made. The fiberglass mesh inside these boards helps them absorb energy without failing. They can take heavy physical stress without cracking or breaking, which makes them great for busy areas where impacts might happen. Thanks to the fiberglass mesh, these boards bend before breaking unlike their brittle fiber cement counterparts.

Weather Tolerance: UV and Rain vs Extreme Conditions

Fiber cement boards do pretty well in normal weather. They can handle moderate moisture and UV rays without much trouble. In spite of that, places with big temperature swings might cause these boards to slowly break down over time.

MgO boards shine in tough weather conditions. They stay strong even when exposed to:

·       Long periods of UV rays without much fading or warping

·       Big temperature changes without splitting or checking

·       Steady humidity without changing size

Near the coast, where salty air makes materials break down faster, MgO boards hold up really well. They keep moisture out, which stops internal damage during freeze-thaw cycles.

Lifespan and Maintenance Requirements

Fiber cement boards can last 50 to 100 years if installed and maintained properly. To reach this lifespan, they need regular care:

·       Yearly cleaning to remove dirt and possible mold

·       New paint every 10-15 years

·       Regular checks for cracks or gaps

·       Fresh caulking as needed

MgO boards last just as long or longer and need much less maintenance. They naturally resist moisture, mold, and mildew, which cuts down on many common upkeep tasks. These boards keep their shape throughout their life, so you won't need many repairs for warping or swelling.

MgO boards might cost more upfront than fiber cement ones. Still, they often give better value over time because they need less maintenance and last longer in tough conditions. For projects that need to stay strong under changing conditions, MgO boards' better impact resistance and weather tolerance make them a stronger choice than regular fiber cement options.

Environmental and Health Impact

Building materials' effect on the environment has become a hot topic. The construction industry now faces closer examination of how it affects climate change. Construction and demolition waste makes up about 19% of total municipal solid waste in some regions.

Carbon Footprint: Cement Production vs Natural Materials

The cement industry adds roughly 5% to global CO2 emissions worldwide. This environmental load comes from breaking down calcium carbonate, which releases huge amounts of carbon dioxide.

Fiber cement boards carry this carbon-heavy burden. These boards just need substantial energy to produce cement, which leads to a higher carbon footprint. Making cement uses up natural resources through extensive limestone and clay mining.

MgO boards provide a greener option. Making magnesium oxide boards creates lower emissions—about 340 kg of CO2 per metric ton compared to 740 kg for calcium oxide (cement) production. Here's what makes this difference:

·       Mining: Both materials create similar emissions (60 kg/t)

·       Extraction: MgO creates 200 kg/t versus CaO's 600 kg/t

·       Shipping: MgO produces 140 kg/t while CaO creates 60 kg/t

The magnesium boards' curing process gets even better as it captures carbon dioxide, which reduces their overall environmental effect.

Indoor Air Quality: Silica Dust vs Non-Toxic Composition

People spend about 90% of their time indoors, so indoor air quality directly affects human health. Building materials can help or hurt the quality of our living spaces.

Fiber cement boards contain crystalline silica, which creates serious health risks when cut or processed. Workers who breathe these tiny particles face higher risks of developing severe conditions:

·       Silicosis (an incurable lung disease)

·       Lung cancer

·       Chronic obstructive pulmonary disease (COPD)

·       Kidney disease

Danger comes from respirable crystalline silica particles—at least 100 times smaller than regular sand—created when cutting, sawing, grinding, or drilling fiber cement products. About 2.3 million U.S. workers face silica exposure at work.

MgO boards contain no silica, formaldehyde, asbestos, or other harmful chemicals. This makes them a safer choice for installers and building occupants. Their non-toxic makeup works great especially when you have settings where air quality matters most, like hospitals, schools, and homes.

Recyclability and Waste Management

By 2025, the construction industry will create nearly 2.2 billion tons of waste. This shows why we just need recyclable building materials now more than ever.

MgO boards shine with their complete recyclability. These boards can be:

·       Reused as broken pieces in smaller projects

·       Ground down for new construction materials

·       Used to stabilize soil in certain cases

Fiber cement boards offer few recycling options. Most end up in landfills after demolition, which adds to construction waste problems.

MgO boards use naturally abundant materials, often from seawater and brine pools. This extraction method affects the environment less than the heavy mining needed for cement production.

Installation and Cost Considerations

Ground application factors play a crucial role in material selection for construction projects. The choice between mgo board and fiber cement board can substantially affect project timelines, labor costs, and overall satisfaction.

Weight and Handling: Heavy vs Lightweight

These materials' weight difference affects everything from transportation to installation efficiency. Fiber cement boards need more manpower and structural support during installation because of their heavier weight. Extra weight slows down the installation process and increases labor needs.

Magnesium boards give you a lighter option, weighing about 25% less than cement boards. The lighter weight brings several benefits:

·       Workers can handle them more easily

·       Transportation costs go down

·       Supporting structures face less strain

·       Installation moves faster

The weight difference becomes even more obvious in large-scale projects that need hundreds of sheets. To name just one example, 25 sheets of lightweight material weigh around 300 pounds less than standard materials.

Tool Requirements: Specialized vs Standard Tools

You'll need specialized cutting tools for fiber cement boards to handle their density without creating too much silica dust. Installation requires:

·       Tile cutters to shape precisely

·       Notched trowels for mortar application

·       Masonry screws to fasten securely

·       Cement-based mortar for proper adhesion

Standard carpentry tools work fine with magnesium boards:

·       Utility knives cut them easily

·       Squares help measure accurately

·       Circular saws make straight cuts

·       Standard screws designed for mgo boards work well

Tool requirements definitely affect both your initial equipment investment and the time needed to learn proper installation techniques.

Material and Labor Costs: Upfront vs Long-Term Value

Fiber cement boards cost less upfront. They've become a construction standard in part because they're affordable and easy to find. Budget-conscious projects often find fiber cement's original price appealing.

Magnesium boards might cost more initially but could save money long-term through:

·       Lower labor costs from faster installation

·       Less maintenance over time

·       Better durability in tough environments

·       Smaller crews can handle the work

Smart project planning looks at transportation, installation speed, durability, and maintenance needs. Projects with tight schedules might benefit from mgo boards' faster installation, which could make up for higher material costs through labor savings.

Use Cases and Application Scenarios

Building materials prove their worth through their ground applications in projects. Learning about where each board type works best helps determine their ideal uses.

Residential Use: Bathrooms, Kitchens, and Siding

MgO boards work great in residential wet areas because they resist moisture better than alternatives. These boards work especially when you have bathrooms, kitchens, laundry spaces, and basements with high humidity levels. Magnesium boards keep their structural integrity even after long water exposure, which makes them perfect for shower walls and bathtub surrounds.

Fiber cement boards lead the way in exterior applications like siding, roof underlayment, and decorative finishes. Their defense against weathering, rot, and insect damage makes them a smart choice for outdoor residential elements.

MgO boards bring advantages to subflooring and interior wall panels in homes. Their lighter weight makes installation easier in tight spaces, and their natural mold resistance creates healthier indoor spaces, particularly in damp areas.

Commercial Use: Hospitals, Schools, and Offices

Commercial buildings need good acoustics and durability. MgO boards deliver excellent soundproofing features that work well in offices, recording studios, hospitals, and schools. This sound control and non-toxic makeup creates better indoor environments in busy buildings.

Fiber cement boards shine on commercial exteriors that face harsh weather. These boards are budget-friendly for large commercial projects because they last long with minimal upkeep.

Healthcare facilities benefit from mgo boards' antimicrobial properties and lack of harmful chemicals, which leads to better air quality in sensitive spaces.

Fire-Rated and Wet Area Applications

Fire resistance stands as a vital safety requirement that building codes often mandate. MgO boards excel at fire protection and can withstand temperatures up to 1200°C without failing. This makes them ideal for fire barriers, electrical cable protection, and safeguarding critical building structures.

MgO boards' fire ratings reach 120 minutes in certified systems, which gives people significant evacuation time during emergencies. Builders now specify these boards more often for fire-rated walls, fireproof partitions, and ceilings where fire safety matters most.

Fiber cement also qualifies as non-combustible material for fire-rated applications, though it handles lower temperatures than magnesium options.

MgO boards offer a complete solution when spaces need both moisture and fire resistance. These boards keep their mechanical properties even after 25 cycles of water soaking and drying, which makes them superior for situations with both fire and moisture exposure.

Comparison Table

Conclusion

A detailed analysis of MgO and fiber cement boards reveals clear differences in their performance characteristics. MgO boards without doubt provide better fire resistance and can withstand temperatures up to 1200°C, while fiber cement boards max out at 750°C. This makes magnesium boards a superior choice when fire safety matters most.

MgO boards show excellent moisture resistance and keep their structural integrity even after long exposure to water. These boards naturally resist mold and mildew, making them perfect for bathrooms, kitchens, and humid spaces. Magnesium boards weigh 25% less than fiber cement, which makes installation easier and cuts down labor costs.

MgO boards shine on the environmental front with reduced carbon emissions during production and complete recyclability after use. Workers and building occupants stay safer thanks to the absence of silica dust during installation.

Fiber cement boards remain competitive with cheaper upfront costs and proven durability outdoors. Their 50-year-old track record in siding and weather resistance makes them reliable for standard construction projects.

Project requirements determine the best choice between these materials. MgO boards work better in moisture-prone areas, fire-rated applications, and projects that prioritize environmental impact and indoor air quality, despite higher costs. Traditional fiber cement products might suit standard exterior applications with tight budgets better.

Both materials will evolve through 2025 and beyond. MgO boards' improved performance makes them a forward-thinking choice for construction professionals who want safety, sustainability, and durability combined. The higher cost of magnesium boards pays off through less maintenance, better performance, and healthier living spaces throughout the building's life.

www.magmatrixboards.com

www.jinpenggroups.cn