A Guide to Using Magnesium Oxide Board for Exterior Wall Insulation

09 Sep A Guide to Using Magnesium Oxide Board for Exterior Wall Insulation

If you want a strong choice for exterior wall insulation, magnesium oxide board is a good pick for many reasons. You get great fire protection, strong moisture defense, and a solution that is good for the environment. These boards stop mold, bugs, and damage from salt if you cover them well. You can use them in buildings that need to be tough, like schools, hotels, or hospitals. But you need extra insulation because these boards do not keep heat in very well. It is important to install them carefully, especially in wet places, because boards can soak up water and make fasteners rust. Always think about your building type, local weather, and how much energy you want to save.

• Key strengths of magnesium oxide board for exterior use:

  • Fireproof and mold proof

  • Very strong and not heavy

  • Simple to put up and finish

• Limitations to remember:

  • Boards keep out moisture but are not fully waterproof

  • Need coated fasteners and good storage

  • Quality is different for each maker

Key Takeaways

• Magnesium oxide board is good at stopping fire, water, and mold. This makes it great for strong outside walls. These boards are light and strong. They are also good for the environment. They help you make safer and greener buildings. You must install them with rust-proof fasteners. You also need to seal the edges. This keeps the boards dry and helps them last longer. Magnesium oxide board works better with extra insulation and a cover. This helps keep heat in and blocks bad weather. Magnesium oxide board costs more at first. But it saves money later. You will spend less on repairs and care than with gypsum or fiber cement.

Magnesium Oxide Board for Exterior Use

What Is Magnesium Oxide Board

You might ask why magnesium oxide board is special. Magnesium boards have magnesium oxide as their main part. Makers mix it with magnesium sulfate or magnesium chloride. They also add wood fibers, perlite, and fiberglass mesh. This mix makes the boards strong and gives them special features. Magnesium boards do not have bad chemicals like formaldehyde. These boards can be recycled and are good for the planet. They help you build safer and greener places.

Here is a table that shows how magnesium oxide board is different from other wall materials:

You can look at this chart to see the chemical differences:

Key Properties for Exterior Walls

Magnesium oxide board gives you many good things for outside walls. These boards are great at stopping fire, so your building is safer. They also keep out water, so they do not rot or get mold easily. Bugs and salt do not hurt these boards much, so they work well outside.

Magnesium boards are best as a base layer. You need to cover them with cladding or special coatings. This keeps them safe from rain, sun, and wind. The boards let moisture out instead of trapping it. This helps stop mold and mildew. Magnesium boards are not waterproof, but they do not fall apart after getting wet and drying. Sulfate-based boards fight rust better, which is good near the ocean or in wet places.

Tip: Always use fasteners that do not rust and seal the edges of magnesium boards. This keeps your outside walls strong and safe.

New ways to make magnesium oxide board make it even better for outside use. Now, boards are stronger, can handle more wind, and look nicer. These boards are safe for the planet and do not have toxins. When you pick magnesium boards for your outside walls, you help the environment.

MgO Board Benefits

Fire Resistant Performance

You want your outside walls to stop fire. Magnesium boards are very good at this. These boards do not catch fire or help flames spread. Mgo board keeps your building safe even in very hot conditions. The fire resistance rating for mgo board is Class A1. It can handle heat up to 1200°C and stay strong for 4 hours. If fire touches these boards, they do not make dangerous smoke or gas.

Here is a table that shows how mgo board does against other wall materials for fire resistance:

Magnesium boards pass tough fire safety tests like ASTM E136, ASTM E84, EN 13501-1, and Canadian codes. You can use mgo board for fire-safe outside walls in schools, hospitals, and hotels. Building rules often need 1- to 2-hour fire resistance for outside walls. Mgo board meets these rules and keeps your building safe.

Moisture and Mold Protection

You need outside walls that can handle rain and damp air. Mgo board is great at stopping water. These boards only take in about 0.34% water on the surface, which is much less than gypsum or plywood. Magnesium boards stay strong after getting wet and drying many times. You do not see them bend, swell, or break apart. The boards stay flat and tough.

Here is a table that shows how mgo board works for moisture and mold resistance:

Magnesium boards have a high pH and are packed tight. This helps stop mold and mildew, even in wet places. Mgo board works well in bathrooms, kitchens, and basements. You can use these boards for strong outside walls in places that flood. The boards stop fungus from growing on top and inside. You should seal the joints and use water barriers for best results.

Tip: Magnesium boards resist water but are not fully waterproof. Always add extra water protection for outside walls in rainy places.

Durability and Sustainability

You want outside walls that last a long time. Mgo board is strong and lasts for years. These boards can last up to 50 years on outside walls. Magnesium boards do not crack, get mold, attract bugs, or break in bad weather. You do not have to replace them often, so you save money and make less trash.

Magnesium boards keep their strength and water resistance as time goes on. Tests show mgo board stays strong after facing wet air, heat, and age. Good magnesium boards, especially with magnesium oxysulphate cement, last over 30 years in normal weather and up to 50 years in tough places.

You help the planet when you pick mgo board. Magnesium boards get green building awards like LEED and BREEAM. The boards do not have bad chemicals like asbestos or formaldehyde. You get cleaner air inside. The boards can be recycled and use less energy to make than cement boards. When they dry, magnesium boards trap 20–40% of the CO2 made during production, which lowers pollution.

• Magnesium boards are certified under EN ISO 1716 and EN 13501 for fire safety.

• The boards use natural magnesium sulfate and do not have harmful stuff.

• You get strength, fire safety, water resistance, and mold resistance in one board.

• The boards can be recycled and help protect the earth.

Note: Magnesium boards give you a strong, safe, and earth-friendly choice for outside walls. You get protection that lasts and help the planet too.

Installation and Cladding Systems

Installation Steps

To put up magnesium oxide boards on outside walls, follow some simple steps. First, measure and mark the boards so they fit your wall. Cut the boards with a utility knife or a saw with a diamond blade. Always wear gloves and goggles to stay safe. Clean the wall and check that the frame is flat. Start at the bottom and attach the boards with screws or nails that do not rust. Put fasteners every 6 inches on the edges and 12 inches in the middle. Make sure each board is straight before you add the next one. Cover the seams with tape or glue that keeps out water. Do not let the boards get wet from rain while you work. Water can make the boards weaker. You can also use these boards for roofs, but keep them dry until you finish the outside layer.

Tip: Only use fasteners that do not rust and keep the boards dry while you work for the best results.

Cladding Compatibility

You have lots of options for cladding with magnesium oxide boards. These boards work with most outside coverings because they block fire, water, and sun. You can use them with brick, stone, or siding. If you use brick or stone, make sure water can drain and dry out. This stops water problems. Some coverings, like stucco, can make fasteners rust if you do not use the right kind. Always pick a barrier that works with both the boards and the outside covering. Boards with special water blockers and fiber are even better against weather. You can use these boards under roof shingles or tiles too. If you add insulation panels, you get warmer walls and save energy.

• Key points for cladding compatibility:

  • Pick outside coverings that are as strong as the boards.

  • Use good barriers to stop water from getting behind the boards.

  • Do not use coverings that trap water.

Common Challenges

You might run into some problems with magnesium oxide boards. These boards are tough and heavy, so you need special blades to cut them. If you are rough, the boards can crack. Nails do not hold as well as screws or anchors, so use those instead. The boards feel rough and may need extra work like coating and sanding. Sometimes, it is hard to find these boards because there are not many or shipping is slow. If you pick the wrong kind, the boards can soak up water and make fasteners rust, especially on roofs or outside walls. Always check the boards are good quality and have low chloride for better heat and water control.

Note: Magnesium oxide boards do not keep heat in as well as foam. For warmer walls, use them with fiberglass or foam panels.

Comparing Exterior Insulation Materials

MgO Board vs Fiber Cement

When you compare mgo board to fiber cement, you see clear differences. Both boards resist fire and moisture, but mgo board gives you better protection. Mgo board has a lower thermal conductivity, so it keeps your building cooler and saves energy. Fiber cement absorbs more heat and can crack over time. Mgo board is lighter, so you can install it faster and with less effort. You also get better mold resistance with mgo board, which helps in wet climates.

Here is a table to help you see the differences:

Tip: Mgo board gives you better thermal performance and moisture protection, making it a smart choice for exterior walls.

MgO Board vs Gypsum

You might wonder how mgo board compares to gypsum. Mgo board stands out because it is much stronger and lasts longer. You can install mgo board quickly, and you do not need special tools or corner beads. Gypsum boards need more care during installation and take longer to finish. Mgo board resists water, mold, and pests, so you spend less time on repairs. Gypsum boards can swell, warp, or break if they get wet. For outside walls, mgo board gives you better fire safety and less maintenance.

• Mgo board can handle rain, wind, and even freeze-thaw cycles.

• Gypsum boards work best indoors and need more protection outside.

Cost and Performance

You pay more upfront for mgo board than for gypsum or fiber cement boards. The average installed cost for mgo board is $1.50 to $2.50 per square foot. Gypsum boards cost less, about $0.40 to $1.20 per square foot. Even though mgo board costs more at first, you save money over time. Mgo board lasts longer and needs fewer repairs. You do not have to worry about water damage, mold, or pests. Fiber cement boards need more upkeep and sealing to last as long as mgo board. Over the years, mgo board gives you better value because it stays strong and safe.

Note: Mgo board offers high durability, low maintenance, and strong impact resistance, making it a wise investment for exterior wall insulation.

Magnesium oxide board helps protect your walls from fire and water. It is also good for the environment. This material can handle heat, rain, and mold. When you use MgO board, think about your weather, building, and how much energy you want to save.

• Use MgO board if your area has fires or lots of rain.

• Check your local rules and install the boards the right way.

• Keep the boards dry and leave small spaces to stop cracks.

Ask a building expert before you begin. Think about how long the boards will last and if the higher price and work are worth it for your project.

FAQ

Can you use magnesium oxide board alone for insulation?

Magnesium oxide board does not work well by itself for insulation. Its R-value is low, so it does not keep heat in. You need to add foam or fiberglass insulation to stay warm or cool.

How do you protect magnesium oxide board from water?

Seal every joint and edge to keep water out. Use a water barrier or weather-resistant covering. Always choose fasteners that do not rust. Keep the boards dry when you store and install them.

Is magnesium oxide board safe for people with allergies?

Yes, magnesium oxide board is safe for people with allergies. It does not have formaldehyde or asbestos. The board stops mold and mildew, so the air inside is cleaner.

Can you paint or finish magnesium oxide board?

You can paint or finish magnesium oxide board. Pick paints or coatings that let the board breathe. Always follow the maker’s directions for the best results.