Products / Interior / HardieBacker® 500
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 Cement Board with Moldblock™ Technology
Basic Composition/Size90% Portland cement and ground sand. HardieBacker board contains no asbestos, glass mesh, formaldehyde, or gypsum.
Mold ResistanceHardieBacker 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.
ApprovalsHardieBacker cement board is recognized as an interior substrate according to the following:
Flexural StrengthBased on typical Equilibrium Moisture Content: 2100 psi when tested in accordance with ASTM test method C1185.
Non-CombustibilityHardieBacker cement board is recognized for use in non-combustible construction in NER-405.
Surface Burning CharacteristicsWhen tested in accordance with ASTM test method E-84:
Thermal Resistance(Approximate value) 1/4'' thick: R:0.13
HardieBacker 500 Cement Board Press & Praise
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HardieBacker Cement Board with Moldblock™ technology
Limited Lifetime Product Warranty
HardieBacker Cement Board - Exterior Use
(AL, AR, GA, HI, FL, LA, MS, OK, SC, TX, PR
and limited areas of AZ, CA, KY, NC, NM, NV, OR, TN, VA, & WA)
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HardieBacker® 500 board FAQ
Use the online James Hardie preferred dealer locator or call customer service at 1-888-JHARDIE for your closest sales representative.
HardieBacker board may be cut with a carbide-tipped scoring knife, utility knife, or cutting shears (manual, electric or pneumatic).
Home Depot® stores and Lowe's Home Improvement Warehouses®.
Either is acceptable, but we recommend that the smooth side with the nailing pattern of every 8" on center go up.
The minimum subfloor specified is 5/8" exterior grade plywood or 23/32'' exterior grade OSB subflooring. HardieBacker board must be installed in accordance with local building codes and the floor must be engineered not to exceed the L/360 deflection criteria, including live and dead design loads, for the specific joist spacing used. HardieBacker board is not designed for use over concrete.
Dry set (ANSI 118.1) or acrylic modified thinset (ANSI 118.4) is specified between the HardieBacker board and the subfloor to eliminate any deviations between our product and the subfloor. This decreases the probability of popping or cracking tiles due to deflection and air pockets.
The modified thinset used with our product is a fortified cement-based mortar and should specifically conform to ANSI (American National Standards Institute) A 118.4. The thinset can be fortified in a pre-mixed powder form or with a liquid additive.
No. Where HardieBacker board is being installed over a code-complying subfloor for the attachment of tile, the board is installed over a 3/32''-1/4'' thick bed of bonding mortar and then nailed down. ''Liquid Nails'' is not a bonding mortar. It is a structural adhesive generally used to bond the subfloor to the floor joists just prior to nailing. It creates a very solid joint between the surface of the floor joist and the subfloor and aids in reducing floor squeak. The properties of Liquid Nails are such that it is applied via a tube in the form of a bead-like caulking. It is not trowelable like a mortar and therefore results in high ridges with unsupported areas that can deflect under load, resulting in cracked tile.
Where HardieBacker board is being installed directly to wood or metal framing, the use of a structural adhesive in addition to mechanical fastening can be used. However, the board must be forced into the structural adhesive almost immediately upon application to insure that no ridge or crown is formed. The creation of a crown or ridge will result in an additional thickness of mortar being applied to fill in the valley created by the crown. This will require a longer curing time and result in a weaker bond between the tile and the mortar and the underlayment. The use of a structural adhesive does not result in fewer fasteners being required.
Fasten HardieBacker sheets with proper nails or screws (as listed in ''Materials Required'' in the backer installation instructions) every 8'' around the perimeter and all supporting studs. Keep fasteners between 3/8'' and 3/4'' from sheet edges and 2'' in from sheet corners.
In compliance with the tile industry, James Hardie recommends 1-1/4'' long galvanized or stainless steel roofing nails (0.121'' shank x 3/8'' HD) or 1-1/4'' long corrosion resistant ribbed waferhead screws (No. 8-18 x 3/8'' HD).
The screws that you are using do not have the power to rout out the material in order for the screw head to sit flush. Be sure to use the specified screws (1-1/4'' No.8-18 by 3/8'' HD Hi-Lo S or S-12 for metal studs, ribbed phil wafer head, self drilling, corrosion-resistant screws). If you continue to have difficulties, we recommend switching to 1-1/4'' galvanized roofing nails.
The tape will help disperse any movement of the substrate, therefore decreasing the probability of popping or cracking tiles along the seams.
Home Depot stores and Lowe's Home Improvement Warehouses.
Yes, Hardiebacker can go over linoleum or vinyl composite tile. Even though you may go over vinyl composite tile, James Hardie does not recommend you install HardieBacker board over cushioned vinyl. Follow HardieBacker board floor installation instructions for complete details.
Yes, HardieBacker board can be used as a fireplace facing. HardieBacker 1/4'' board can be used as a component in a 1-hour fire resistive construction when installed in compliance with National Evaluation Report NER-405. HardieBacker boards are recognized as non-combustible, when tested according to ASTM E 136.
In accordance with National Evaluation Service Report NER-405, HardieBacker board is recognized only as an interior substrate.
Installation GuideDownload Installation Instructions - English [ PDF ]
Download Installation Instructions - Spanish [ PDF ]
Download Installation Instructions - English/French [ PDF ]
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Video: Installing HardieBacker Cement Board Series
Cement Backerboard for Walls,