Magnesium Oxide Board Complete Guide

03 Jul Magnesium Oxide Board Complete Guide

Magnesium oxide board is a tough building panel made from minerals. You can use it where you need more safety from fire, water, or mold. Tests show this board does not burn even at 1200°C. It also keeps its shape after staying in water for days. It resists termites, acids, and mold, so you can trust it in bathrooms, kitchens, or basements. Magnesium oxide board is safer and lasts longer than plywood or drywall.

Key Takeaways

• Magnesium oxide boards do not burn. They do not get damaged by water, mold, or termites. This makes them safer and stronger than drywall or plywood.
• These boards are light and strong. They are good for the environment. They use less energy to make. They help keep indoor air clean.
• You can use magnesium oxide boards inside for walls and ceilings. You can also use them outside as sheathing or siding if you seal them well.
• Use screws that do not rust to install the boards. Leave small spaces between boards so they can expand. Cover the seams with joint compound and sealant.
• Keep the boards in dry places. Keep the air inside dry too. This stops moisture problems and helps the boards last longer.

What Is Magnesium Oxide Board

Composition

A Magnesium Oxide Board is a strong panel for building. It is made from both natural and man-made materials. The main part is magnesium oxide. This makes up about half of the board. Makers mix it with magnesium chloride or magnesium sulfate. These chemicals help hold the board together. Fillers like perlite, wood fiber, and fiberglass mesh are also added. These fillers make the board stronger and more stable.

To make the board, all the parts are mixed into a thick paste. The paste is poured into molds. Then, it is pressed with high pressure. After that, the board is left to dry and harden. This is called curing. When it is cured, the board gets a smooth surface. The finished board is light and feels like stone. You can use it for many building jobs.

Tip: Boards with magnesium sulfate (MOS boards) do better with moisture than boards with magnesium chloride (MOC boards). If you need the board for a wet place, ask your supplier which type it is.

Here is a quick comparison of what goes into different building boards:

Properties

Magnesium Oxide Board has many good features. It does not burn, even in very hot fires. It can handle heat up to 1200°C and still keeps its shape. The board passes tough fire safety tests like EN ISO 1716 and ASTM E84. It gets a Class A1 fire rating.

This board also stops mold and mildew from growing. Its chemicals keep fungus and rot away. Termites cannot eat it because of what it is made from. No toxic chemicals are needed to keep bugs away.

Magnesium Oxide Board is lighter than cement boards by about 20-30%. This makes it easier to move and put in place. The board can bend a little, so it works on curved walls. It stays strong in both hot and cold weather. Freeze and thaw tests show it does not crack or break easily.

Here is a table that shows how Magnesium Oxide Board compares to other common building materials:

Choosing this board helps the environment. Making it uses less energy than making cement boards. The board even traps some carbon dioxide as it dries. It does not have harmful chemicals like asbestos or formaldehyde. This makes it safe for indoor air.

• The board’s minerals and binders give it fire resistance.
• Its chemical makeup stops mold and insects.
• Long freeze and moisture tests prove it is durable.
• The board is safe and non-toxic for homes, schools, and hospitals.

Note: Always check the board’s quality before you buy. Some boards work better in wet places than others. Ask for test results or certifications to make sure you get the right one.

Benefits

Fire Resistance

You can count on magnesium oxide board to protect your building from fire. This board does not burn, even in extreme heat. Many tests prove its safety:

• Suparna MgO boards have an A1 fireproof rating and can withstand fire for at least two hours.
• Trusted labs like SGS and Intertek have tested these boards.
• The boards hold CE and ISO certifications for fire resistance.
• They do not release smoke or odors during a fire.
• MagPanel® boards meet ASTM E84 Class A standards, showing zero flame spread and non-combustibility.

You can use these boards in places with strict fire codes, such as hospitals, schools, hotels, and apartments.

Durability

Magnesium oxide board stands up to tough conditions. You can rely on it for long-term use. Tests show that the board keeps its strength after years of exposure to heat, cold, and moisture. Accelerated aging and environmental simulation tests prove that the board does not lose its core strength, even if the surface changes color or texture. Builders also monitor real buildings over time and find that the board stays strong. You can improve its durability with special coatings or additives.

Moisture Resistance

If you need a board for wet areas, this is a smart choice. Research shows that magnesium oxide board keeps its strength even after months in water. In dry places, the board gets even stronger over time. In wet places, it still holds up well, with only a small drop in strength. Additives like fly ash and phosphate can boost its water resistance. You can use this board in bathrooms, kitchens, or basements without worry.

Eco-Friendly

You help the environment when you choose magnesium oxide board. The board uses natural resources and does not contain harmful chemicals or VOCs. It is recyclable and can be reused in new construction. Making this board uses less energy than making gypsum or cement boards, which lowers carbon emissions. The board even captures CO2 during curing. Its long life and insulation properties help save energy in your building.

Tip: Magnesium oxide board is lighter than cement board and more flexible than drywall. You save on labor and transport costs, and you get a board that works in many places.

Applications

Walls and Ceilings

These boards work for inside walls and ceilings in homes, schools, and offices. First, measure the area you want to cover. Cut the panels so they fit your space. Attach them to wall studs or ceiling joists with screws. Leave a small gap between each panel so they can expand.

Many builders use these boards in bathrooms and kitchens. The panels stop mold and moisture, so water damage is less likely. In Denmark, some boards had trouble in very humid places, like mold and rust. But other boards stayed strong after a year in wet spots. This means you should always check the board’s quality before using it in damp areas.

Tip: Ask your supplier for test results or certifications. Good boards last longer and protect your building better.

Sheathing and Siding

These panels can be used outside as sheathing or siding. First, attach the panels to the outside frame of your building. Use screws that do not rust for best results. Cover the joints with tape or sealant to keep out water and wind.

These panels are a good base for stucco, brick, or other finishes. They give you a strong, fire-resistant layer that protects your building from weather. The panels are light, so they are faster and easier to install than cement boards.

Specialty Uses

You can use these boards for many special projects. Builders use them as tile backers in showers or wet rooms. You can also use them under floors, as fireproof barriers, or even for furniture panels.

• Use as a base for radiant floor heating systems.

• Make fire-rated walls in commercial spaces.

• Build strong signs or display boards.

🛠️ Note: Always follow the manufacturer’s instructions for each use. This helps you get the best results and keeps everyone safe.

Installation

Tools and Materials

You need the right tools and materials to install the boards. Get everything ready before you begin:

🛠️ Tip: Use stainless steel or ceramic-coated screws. These screws do not rust and last longer.

Cutting and Handling

First, measure and mark your boards with a tape measure and square. Thin boards can be cut by scoring and snapping with a utility knife. For thick boards, use a circular saw with a carbide blade. Always wear safety glasses and a dust mask to stay safe from dust.

Carry boards upright with two people. This stops them from bending or breaking. Store boards flat on a dry, supported surface. Do not let boards get wet for a long time. Keep your work area clean and dry to protect the boards.

Fastening

Put each board on a clean, flat surface. Leave a small gap, about 1/8 inch, between boards so they can expand. Start putting in screws from one side and move across. Use corrosion-resistant screws. Place screws at least 4 inches from corners. Put screws 6 inches apart along the edges and 12 inches apart in the middle. Keep screws about 9/16 inch from the edge. Do not put screws in at an angle.

⚠️ Note: Always follow the manufacturer’s instructions and local building rules for the best results.

Finishing

After you fasten the boards, put joint compound or glue on all the seams. Use a trowel to make the surface smooth. Let the compound dry, then sand it until it is flat. Put on a primer or waterproof sealant to protect the board and make it last longer. If you want to paint or tile, make sure the surface is clean and dry first.

👍 Expert Tip: Let the boards sit in the room for 48 hours before you start. This helps stop the boards from warping.

Magnesium Oxide Board Comparison

Drywall

You often see drywall in homes and offices. It is easy to cut and install. Drywall costs less than many other boards. However, drywall does not handle water well. If you use it in wet areas, it can grow mold and break down. Drywall also burns in a fire. If you want better fire and moisture protection, you should choose magnesium oxide board instead.

Cement Board

Cement board works well in wet places like bathrooms. It resists water and mold. However, cement board feels heavy and can be hard to cut. You may need special tools for installation. When you compare it to magnesium oxide board, you see some clear differences:

You get better impact resistance and freeze/thaw durability with magnesium oxide board. It also weighs less than cement board, so you can install it faster. For outdoor use, you need to seal magnesium oxide board to stop moisture from causing expansion.

Plywood

Plywood is strong and light. You can cut it with simple tools. Many builders use plywood for floors and walls. However, plywood can swell or rot if it gets wet. The glue in plywood may fail over time. Magnesium oxide board gives you more consistent strength and better resistance to water and insects. You will find it easier to install than cement board, and it does not have the glue problems of plywood.

MOS Board

You may hear about MOS board when you shop for building panels. MOS stands for magnesium oxysulphate. This board uses magnesium sulfate instead of magnesium chloride. MOS board does not have chloride ions, so it avoids some moisture problems. You will see less mold and corrosion with MOS board. However, it has lower strength than regular magnesium oxide board. Both types resist fire well. If you need a board for a damp place, MOS board can be a safer choice, but it may not be as strong.

📝 Tip: Always check the chemical type before you buy. Ask your supplier if the board uses magnesium chloride or magnesium sulfate. This helps you pick the right board for your project.

Drawbacks and Maintenance

Limitations

You should know about some challenges before you choose this material. High humidity can cause problems, especially with boards made from magnesium oxychloride cement (MOC). When the air stays damp, these boards may start to “cry” or “sweat.” You might see salty water droplets form on the surface. This can lead to mold, corrosion, and even damage to the board. Studies show that about two-thirds of MOC boards begin to break down in less than two months if kept in very humid places. Boards made with magnesium oxysulphate (MOS) do better in wet conditions and do not show this sweating problem.

Humidity cycling, where the air gets wet and then dry again, can also weaken the board. Over time, this can cause cracks or make the board less stable. Experts recommend keeping the relative humidity around 30% to help prevent these issues.

You may also face other limitations:

• The cost of raw materials can change, making the boards more expensive.

• Some areas have limited supply, so you might not find the board easily.

• Shipping costs can be high if the factory is far away.

• Competing products like cement board or plywood may be cheaper or easier to get.

⚠️ Note: Always ask your supplier about the type of board and check for certifications. This helps you avoid problems with moisture and quality.

Care and Longevity

You can make your boards last longer with the right care. These panels resist fire, pests, and mold, so you do not need to treat them with chemicals. They also stay strong in hot, cold, or wet weather. To keep them in good shape, follow these steps:

1. Store boards in a dry place before you install them.

2. Keep indoor humidity low, around 30%, to stop sweating or mold.

3. Use corrosion-resistant screws and seal all joints to block water.

4. Clean the surface with a damp cloth if needed. Do not use harsh cleaners.

5. Check for any signs of water leaks or damage, especially in bathrooms or basements.

Here is a table to help you remember the best care tips:

Research shows that these boards can last many years, even in tough weather. They keep their shape and strength better than wood or drywall. Certifications from ICC-ES and ASTM prove their safety and durability. If you follow these care steps, you will enjoy a long-lasting, low-maintenance wall or ceiling.

You get lots of good things when you pick these boards for your project.

• These boards stop water and mold, so they are great for bathrooms, kitchens, and basements.

• They do not have bad chemicals, so you can use them in hospitals and schools.

• Sometimes, the boards cost more, are hard to find, or need special tools to put in.

• Always look at what binder is used before you buy.

  To get the best results, read the instructions and check the technical papers from the maker.

FAQ

How do you cut magnesium oxide board?

You can score thin boards with a utility knife and snap them. For thick boards, use a circular saw with a carbide blade. Always wear safety glasses and a dust mask to protect yourself from dust.

Can you paint or tile over magnesium oxide board?

Yes, you can paint or tile over it. Make sure the surface is clean and dry. Use a primer before painting. For tile, apply a suitable adhesive. Always follow the manufacturer’s instructions for best results.

What screws should you use for installation?

Use corrosion-resistant screws, such as stainless steel or ceramic-coated types. These screws prevent rust and keep your boards secure. Place screws at least 4 inches from corners and follow spacing guidelines for strength.

Is magnesium oxide board safe for indoor air quality?

Yes, magnesium oxide board does not contain harmful chemicals like asbestos or formaldehyde. It does not release VOCs. You can use it safely in homes, schools, and hospitals.

How do you store magnesium oxide boards before installation?

Store boards flat in a dry, covered area. Keep them off the ground to avoid moisture. Do not let them get wet before installation. This helps prevent damage and keeps the boards strong.