Learn about Magnesium Oxide Board

Magnesium board is a non-insulating, sheathing product used for similar applications to gypsum-based drywall and plywood. It is mold-resistant, fire-resistant, water-resistant, durable, and contains no VOCs. It is commonly referred to as MgO board, magnesium oxide board, or magnesium oxide wallboard. Magnesium board is used for interior or exterior walls, ceilings, flooring, soffits, fascia, underlayment, and tile backing.

Magnesium board is made with magnesium oxide, a mineral cement, and is available in a variety of sheet sizes, colors, grades, and textures. Magnesium board is unlikely to impact indoor air quality negatively and is considered to be a high quality "green" product. Roughly 70's of the world's MgO deposits are located in China and the Mideast, where MgO has been used for decades.

Magnesium board is available in various forms and sizes. It's often sold on its own as non-insulated boards, or as an insulated wall assembly with foam or other material. Magnesium board can be purchased in various grades, such as rough, smooth, and utility, and is often available in white, grey, or beige. Smooth grade is ideal for painting, while rough grade is used for non-aesthetic purposes.

Magnesium board has only been approved for construction in the United States since 2003, so it is still considered a new and progressive building technology. Ensure the product is coated and waterproofed if it is going to be used for exterior applications. It is also common for magnesium oxide boards to come from China with varying degrees of quality. When choosing magnesium oxide boards for your project, choose a manufacturer and installer with extensive experience and a positive reputation. Ask where and how the product was manufactured to ensure it's quality.

Following a very costly failure of magnesium board construction in Denmark in 2010-2015, extensive research has been done to avoid the same mistakes. In this particular case, the product was used for exterior sheathing without proper waterproofing applied.

Magnesium boards are a very safe and durable material for home construction. They are non-toxic and don't off-gas VOCs, making them an excellent choice for interior walls. They are durable and resistant to moisture, fire, and mold, so they are less prone to damage than similar alternatives.

70% of the world's magnesium oxide deposits are located in Asia. "Magnesium board" is a bit of a misnomer, as magnesium alone is a metal-like substance that is flammable and unstable. It's so flammable that it's even used for fireworks. When oxygen is added, the resulting magnesium oxide is stone-like and non-flammable.