Magnesium Oxide (MgO) board is a synthetic, insulating sheathing board. It is similar to gypsum and fiber cement boards, but with several improved characteristics such as fire-, pest- and mould resistance, weather ability and strength. It is used indoors and out for structural purposes such as walls and semi-structurally in flooring underlays. Paint, plaster and coverings such as wallpaper and tiles can be applied directly to the board, as it has excellent adhesive/bonding characteristics.

The composition of MgO Board consists of multiple layers - a surface layer on the outside of the board; fiberglass net reinforcing layers; filler layers that include the magnesium cement agent, perlite and wood chips; and an inner filler layer. The result is a product that resists impact damage, salt/brines, chlorine bleach, ammonia and related chemicals, moulds, fungus, termites and other organisms. As such, MgO is one of the most innovative, cost-effective and efficient materials on the market.