From the manufacturer that brought AdvanTech™ Subfloor Assemblies and ZIP System™ Building Enclosures to market, Huber Engineered Woods has just expanded its line of EXACOR™ Magnesium Oxide (MgO) panels to include wall sheathing, marking a major addition to the company’s firerated assembly offerings. The MgO structural panels – now available for subfloor, subfloor underlayment and wall applications – are engineered with commercial and multifamily builders’ needs in mind.

EXACOR™ wall sheathing panels are cementitious panels primarily made of inorganic materials reinforced with layers of glass fiber mesh. They are manufactured under a quality control program with inspections by ICC-ES and Underwriters Laboratory (UL) to ensure consistent product performance. The panels exhibit structural values approaching wood sheathing with fire resistance similar to gypsum panels.

The panels can be easily installed by framing crews familiar with installing OSB or plywood sheathing. Additionally, the panels provide a fire-resistant solution that may help reduce the number of layers needed in 2-hour fire-rated exterior wall assemblies for Type III Construction. For instance, in most conventional gypsum-based exterior wall assemblies, two layers of Type X gypsum panels are needed on either side of the wall assembly or the addition of certain exterior siding materials is required to achieve two hours of fire-resistance. The published 2-hour EXACOR MgO exterior wall assembly features a single layer of MgO on the exterior side of the assembly, helping reduce material and cost of labor while still providing fire-resistance and structural performance.

“Over the past year, we’ve seen how EXACOR panels in underlayment and subflooring assemblies are helping to meet the sound attenuation and fire-resistance rated needs of builders around the country, and we continue to learn from our trusted builder and architectural partners who align with the Huber philosophy of better building,” said Kate Land, General Manager, MgO Products for Huber Engineered Woods. “As Huber’s first major offering in fire-rated exterior wall assemblies, EXACOR opens the door to industry-wide innovation for multifamily and light commercial builds to help save our partners time and money.”

For more information on the Huber Engineered Woods portfolio of products, visit For more information on EXACOR wall sheathing, visit