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Products / Interior / HardieBacker® 500

Cement Board

HardieBacker 500 Cement Board for walls and floors delivers superior protection against moisture damage and mold growth. It contains no paper facing, which serves as a food source for mold, or gypsum, which can disintegrate with continuous moisture exposure. HardieBacker cement board is an ideal choice for wet area walls; its smooth surface may be painted, textured, wallpapered, or tiled. HardieBacker 500 cement board is available in a 3´x 5´ and 4´x 8´ sheet size and is backed by a limited lifetime product warranty.

HardieBacker 500 Cement Board

Thickness: 0.42"
Weight: 2.6 lbs./sq. ft.

3' x 5'
4' x 8'

HardieBacker Cement Board with Moldblock™ Technology
Product Specifications

Basic Composition/Size

90% Portland cement and ground sand. HardieBacker board contains no asbestos, glass mesh, formaldehyde, or gypsum.

  • Sheet Size:
  • 3'x 5'
  • 4'x 8'
  • Thickness: 0.42"
  • Weight: 2.6 lbs/sq.ft.

Mold Resistance

HardieBacker cement board products achieve a perfect score on both industry standard mold tests. HardieBacker cement board scores a 0 (best possible score) on the ASTM G21 for mold resistance and a 10 (best possible score) on the ASTM D3273 test against mold growth.


HardieBacker cement board is recognized as an interior substrate according to the following:

Flexural Strength

Based on typical Equilibrium Moisture Content: 2100 psi when tested in accordance with ASTM test method C1185.


HardieBacker cement board is recognized for use in non-combustible construction in NER-405.

Surface Burning Characteristics

When tested in accordance with ASTM test method E-84:
Flame Spread
Fuel Contributed
Smoke Developed

Thermal Resistance

(Approximate value) 1/4'' thick: R:0.13

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