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EXACOR™ Underlayment

EXACOR™ underlayment panels are specifically engineered to meet the fire-rating[1], sound-rating[1] and dimensional stability requirements of most multifamily and light commercial jobsites. Made of magnesium oxide and an integrated mesh core, EXACOR underlayment panels are fire resistant[2]. In addition, EXACOR underlayment panels can offer a base for floor coverings that can eliminate the need for gypsum underlayment and the jobsite delays that may come with it.

  • Underlayment Panel, 1/2" × 4' × 8'

  • Underlayment Panel, 1/2" × 4' × 9'

  • Underlayment Panel, 1/2" × 4' × 10'

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01 Products

Underlayment Panel, 1/2" × 4' × 8'

Panel Count 38
Fire Resistance ASTM E119, ANSI/UL 263

Underlayment Panel, 1/2" × 4' × 9'

Panel Count 33
Fire Resistant E84

Underlayment Panel, 1/2" × 4' × 10'

Panel Count 32
Fire Resistant E84

Performance Category

Panel Size

Edge Profile

Fire-Resistant Assemblies

Code Evaluation Report

Approx. Weight Per Panel

Panels Per Unit

Nominal 1/2" Thickness (12 mm)Nominal 4' × 8' (1220 mm × 2440 mm)Straight (Square) EdgeUL L528ESR-475086.4 lbs.38
Nominal 1/2" Thickness (12 mm)Nominal 4' × 9' (1220 mm × 2743 mm)Straight (Square) EdgeUL L528ESR-475097.2 lbs.33
Nominal 1/2" Thickness (12 mm)Nominal 4' × 10' (1220 mm × 3048 mm)Straight (Square) EdgeUL L528ESR-4750108.0 lbs.


02 What Is MgO

Magnesium oxide (MgO) offers simple strength and streamlined installation for a building panel with exceptional workability.

MgO panels are cementitious panels that are primarily made of inorganic materials reinforced with layers of glass fiber mesh. EXACOR™ MgO panels are manufactured to provide a streamlined solution for strength, fire resistance and sound performance.

Learn More About MgO

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  • Speed & Ease of Installation

    Installs with just a single trade and can eliminate the need for gypsum underlayment.

  • Sound Absorption

    Can help achieve sound ratings when used as a part of a STC/IIC-tested floor/ceiling assembly.

  • Fire Resistance[2]

    Provides fire resistance as part of fire-resistance-rated floor/ceiling assemblies

  • Dimensional Stability

    Withstands exposure to moisture and does not warp, expand, cup or delaminate like other (wood) panels do.

  • Inherent Strength

    Contains a proprietary layered mesh reinforcement for added structural value.

  • Quality Assurance

    Manufactured under a quality control program with inspections by ICC-ES and Underwriters Laboratory (UL) to ensure consistent product performance.

  • Optimize Material & Labor Costs

    High-performing material that may save time and help reduce materials and trades needed to install.

05 Warranty

Warranty Information

See our 10-Year Limited Warranty. Limitations and Restrictions may apply.

View Warranty