Key Features

  • Specialist non-combustible fiber cement board technology for the construction of rated floor assemblies and fire rated ceiling assemblies; a lightweight alternative to poured concrete.
  • Non-combustible per ASTM E136; up to 2 hour fire-rated floor assemblies.
  • ICC Code Acceptance with ICC-ES Report ESR-1219 as non-combustible structural sheathing.
  • International Building Code Approval (IBC).
  • International Residential Code Approval (IRC).
  • Excellent load bearing performance, with UL listed floor assemblies; structural loading bearing sheathing over supports out to 24” on centers.
  • Excellent acoustic insulation, with STC and IIC rated assemblies.
  • Cuts and installs using standard carpentry tools and equipment.
  • Compatible with most traditional floor finishes.
  • Moisture resistant, insect / vermin proof, and impact resistant.
  • Environmentally safe and manufactured with recycled materials


CemDeck is specified and listed under CSI Division 3-03500 Cementitious Decks and Underlayment.


  • UL & ULC classified for use in fire-rated construction (UL 723, Test for Surface Burning Characteristics of Building Materials; UL 790, Test Methods for Fire Tests of Roof Coverings; and UL 263, Fire Tests of Building Construction and Materials).
  • Non-combustible per ASTM E136; 1 and 2 hour fire-rated floor assemblies.
  • Zero flame spread and zero smoke development per ASTM E84.

Load bearing:

  • Structurally span rated, with UL listed floor assemblies

Acoustic insulation:

  • STC rated assemblies per ASTM E413
  • IIM rated assemblies per ASTM E989

Moisture resistance:

  • Factory sealed against water penetration.


  • Minimal dimensional changes in temperature & moisture variations


  • No food value to insects / vermin


  • 71% Portland cement
  • 19% mineralized cellulose fibers (derived from recycled cardboard cartons)
  • 9% water
  • 1% bonding agents.


  • Available in 4’ x 8’ sheets
  • Thicknesses 3/4”, 7/8” and 1”.


Specification & Certification

Building Code approvals

Combustion Characteristics

Fire-Rated Assemblies (ASTM E-119)

Load Tables

Acoustic Performance (STC & IIM):

NYC Dept of Buildings, Materials & Equipment, Acceptance Division:

Weathering Test Reports


  • USAP recommends 8 diameter minimum x applicable length, corrosion resistant screws with self-countersinking heads and self-drilling ‘Tek’ points. The length of the fastener should be a minimum of 2x the board thickness.
  • For attaching 20mm (3/4″) Plycem Cem-Deck boards to steel framing (20 – 12 gauge)
    1. Grabber Part No. HS8158JBWG2 (#8 x 1-5/8″)
    2. Hilti PWH SD Cement Board Screw, No. 00372760 (#8 x 1-5/8″)
    3. ITW Buildex S-12 ‘Rock On’ No. 2159500 (#8 x 1-5/8″)
    4. Pro Twist Cement Board Fasteners
  • Screw Fastener Pull-Out Test Report


Compounds, Sealers & Stains