Installation Guide
Skim coat is recommended to be 1/8"
- 1/4" thick and the tile/stone is to be
installed while the skim coat is wet.
CAUTIONS: This product shall not be
used in the following applications:
• As a backer board in balcony railings
and balcony parapet walls
• HardieBacker 500 may not be used
to a height exceeding through the
second-story above grade or greater
than 30 feet above grade.
¹ See IRC Table R703.4, IBC §2101.2 and
§1405.10
VINYL AND RESILIENT FLOORING (Interior Application Only)
Materials Required
1 | Fasteners
• Minimum 7/8” long galvanized or polymer-coated 18-gauge chisel point staples
with 1/4”crown.
• Minimum 7/8” long galvanized ring shanked underlayment ooring nails.
• Fasteners should be long enough to reach the bottom of the suboor, but not
penetrate it.
• Avoid using resin, rosin or cement-coated fasteners that can discolor vinyl ooring.
2 | Patch
• Use the cement-based, rapid-setting patching compound recommended by the
oor covering manufacturer.
• Do not use a gypsum-based patch. Follow the patch manufacturer’s instructions.
Preparation for Underlayment
1 | Ensure subfloor is structurally sound and properly installed
On existing floors:
• HardieBacker
®
cement board may be installed under or over Vinyl Composition Tile
(VCT) and other resilient ooring. For best results, remove existing oor covering,
especially if it is in poor condition.
• If installing HardieBacker cement board over existing oor, ensure the oor is at
and oor covering is thoroughly adhered to the suboor.
On all floors:
• Ensure suboor is not damaged. Replace any loose, warped, uneven or damaged
sections of oor.
• Make sure suboor is dry, level and fastened correctly. All fasteners must be
countersunk or ush with the suboor. All seams or other areas that are not level
must be sanded at.
• Suboor must be free of all debris, oil, grease, paint or other foreign substances.
2 | Basements and crawl spaces
• Crawl spaces must be well ventilated with a minimum of 18” between the ground
and joists. A vapor barrier over the ground is required.
5 | English