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Fire-rated OSB sheathing panel vs Magnesium Oxide Board

What is the rated OSB sheathing panel?

Fire-rated OSB (Oriented Strand Board) sheathing panels are engineered wood panels treated with fire-resistant chemicals to improve their performance in case of fire. Here are some key features and benefits of these panels:

1. Fire Resistance: These panels are designed to slow the spread of fire, enhancing the building's safety. They comply with fire safety codes and can contribute to a higher fire rating for the entire structure.

2. Strength and Durability: Like standard OSB, fire-rated OSB panels are known for their strength and durability. This makes them suitable for various structural sheathing applications in residential and commercial construction.

3. Versatility: Fire-rated OSB panels are not limited to a specific application. They can be used for wall, roof, and floor sheathing, both indoors and outdoors, making them a versatile choice for a wide range of construction projects.

4. Cost-Effective: Fire-rated OSB panels are generally less expensive than other fire-resistant building materials, making them a cost-effective choice for large projects.

5. Ease of Installation: Standard woodworking tools can cut and install these panels. They are also typically lighter than other fire-resistant materials, making them easier to handle and install.

However, it's important to note that while fire-rated OSB panels are more resistant to fire than standard OSB, they are not fireproof. They should be used as part of a comprehensive fire safety strategy that includes other measures such as fire-resistant insulation and proper electrical wiring. This underscores the need for a holistic approach to fire safety in construction projects.

Fire-rated OSB sheathing panel disadvantages

While fire-rated OSB (Oriented Strand Board) sheathing panels offer many advantages, they also have a few disadvantages to be aware of:


1. Moisture Sensitivity: Like all OSB, fire-rated OSB panels can be sensitive to prolonged exposure to moisture. If not properly protected or exposed to water for extended periods, this can lead to swelling, warping, or even rotting.


2. Chemical Treatments: Fire-rated OSB panels are treated with fire-resistant chemicals. While these treatments increase the material's fire resistance, they can raise concerns about environmental impacts and indoor air quality.


3. Less Fire Resistant than Some Alternatives: Fire-rated OSB panels are more fire-resistant than standard OSB, but they are not as resistant as other materials, like gypsum boards or magnesium oxide boards.


4. Weight: Although lighter than some alternatives, OSB panels are heavier than plywood of the same thickness. This can make handling and installation more challenging in some cases.


5. Aesthetics: OSB panels typically have a rough, flakey surface and aren't considered as visually appealing as other materials. While this isn't an issue if they will be covered with siding or drywall, it can be a disadvantage in applications where the panels will be visible.


6. Potential for Formaldehyde Emissions: Some OSB panels are bonded using adhesives that can release formaldehyde, a potential human carcinogen. However, many manufacturers now produce low-emission products that meet stringent health standards.

As with any construction material, it's essential to consider these potential downsides in your specific project and weigh them against the benefits of fire-rated OSB panels.

What is Magnesium oxide board (MGO Board) fire-rated sheathing panel

Magnesium Oxide (MgO) fire-rated sheathing panels are a type of building material gaining popularity due to its numerous advantages. Here are the key features and benefits of MgO fire-rated sheathing panels:


1. Fire Resistance: MgO panels are non-combustible and have a high fire resistance rating. They do not burn and can help to prevent the spread of fires.

2. Strength and Durability: MgO panels are highly impact-resistant and durable, making them suitable for a wide range of construction applications.

3. Water and Mold Resistance: MgO is resistant to water and mold, which makes these panels a good choice for environments where moisture or humidity are concerns.

4. Environmentally Friendly: MgO panels are often made from recycled materials, and their production process is more eco-friendly than that of traditional building materials. They also do not emit toxic fumes when exposed to fire.

5. Versatility: MgO panels can be used for various applications, including interior and exterior walls, ceilings, and flooring. They can also be used as a tile backer board in wet areas like bathrooms.

6. Sound Insulation: MgO boards have excellent sound insulation properties, making them a good choice for buildings where noise reduction is a priority.

7. Pest Resistance: MgO is resistant to pests, including termites, which can be a significant advantage in certain regions.

However, while MgO fire-rated sheathing panels offer many advantages, they can be more expensive than other types. Also, the availability of MgO panels may be limited in some regions, and they may require special handling or installation procedures to prevent edge chipping or cracking.

Fire-rated OSB sheathing panel compared with magnesium oxide board

Fire-rated OSB (Oriented Strand Board) sheathing panels and Magnesium Oxide (MgO) boards are popular construction materials, each with its own set of benefits and drawbacks. Here's a comparison of the two:


Fire-Rated OSB Sheathing Panels



1. Fire Resistance: Fire-rated OSB panels are treated with fire-resistant chemicals, helping to slow the spread of fire.

2. Strength and Durability: OSB is known for its strength and durability, making it suitable for structural sheathing applications.

3. Cost-Effective: Generally, OSB is less expensive than MgO boards, making it a more cost-effective choice for large projects.


1. Water Sensitivity: OSB can swell and degrade over time if exposed to water or high humidity.

2. Chemical Treatments: The fire-resistant chemicals used to treat OSB can raise environmental and health concerns.


Magnesium Oxide (MgO) Boards



1. Fire and Heat Resistance: MgO boards are naturally fire-resistant and can withstand higher temperatures than OSB.

2. Water and Mold Resistance: Unlike OSB, MgO boards resist water, reducing the risk of mold growth.

3. Environmentally Friendly: MgO boards are often made from recycled materials and don't require chemical treatments for fire resistance.



1. Cost: MgO boards are generally more expensive than OSB.


In conclusion, the choice between fire-rated OSB sheathing panels and MgO boards will depend on your project's specific requirements, including budget, fire and water resistance needs, environmental considerations, and the availability of the material.


JP Group – MagMatrix supplies the most advanced BMSC 517 new sulfate MGO board. We have the whole series for the exterior sheathing panel products from the fire-rated structurally exterior sheathing roof sheathing to the subfloor sheathing, and all meet the building code. We have the model to meet the ASTM E136 noncombustible grade to meet the noncombustible construction request and also the timber frame sheathing panel. All are world-class premium options to replace gypsum sheathing, fiber cement sheathing, and OSB or plywood sheathing, and they are also good options for treated OSB sheathing panels. Warm welcome your excellent inquiry and visit us.

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