Installation Guide

1 | English

CUTTING CEMENT HARDIEBACKER

BOARD

• Use a straight edge as a guide to score the

board’s face and snap upward along the

score line. We recommend using a carbide-

tipped scoring knife, but a utility knife may

also be used. The use of shears (manual,

electric or pneumatic) is also acceptable.

• For cutouts and small holes, score around

perimeter and break out from the face side

with hammer.

• NEVER use high-speed power tools (e.g.

saws, grinders, etc.) to cut James Hardie

products indoors as they may generate

excessive silica dust.

• NEVER dry sweep – Use wet dust suppression methods or HEPA vacuum for

clean-up.

• To further limit respirable silica dust exposures, wear a properly-ﬁtted, NIOSH-

approved dust mask or respirator (e.g. N-95 dust mask) in accordance with

applicable government regulations and manufacturer instructions.

COUNTERTOP INSTALLATION

1 | Ensure cabinets are level and secure

• Use minimum 1/2 in exterior grade plywood or equivalent, positioned across the

wood cabinet. Space between plywood supports is not to exceed 16 in on center.

2 | Determine layout of HardieBacker cement board

• Do not align HardieBacker cement board joints with plywood joints.

• Score and snap boards to required sizes and make necessary cutouts.

• We recommend an 1/8 in gap from board edges.

3 | Attach HardieBacker cement board to countertop

• Apply a supporting bed of dry-set mortar or modiﬁed thinset to plywood with a

1/4 in square-notched trowel. Mastic can also be used with a 5/32 in V-notched

trowel.

• Use the fastener pattern as a guide. Fasten HardieBacker cement board with

speciﬁed nails or screws (as listed in “Materials Required") every 8 in over the

entire surface. Keep fasteners between 3/8 in and 3/4 in from board edges and 2

in from board corners.

4 | Tape joints prior to tiling

• Prior to setting the tile, ﬁll all joints with the same mortar used to set the tiles.

• Embed 2 in wide high-strength alkali-resistant glass ﬁber tape in the mortar

and level.

5 | Exterior application (Limited to HardieBacker 500 in HZ10

climate zones)

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Additional details on page 4

• Follow Countertop installation steps 1 thru 4

• Mastic (organic adhesives) shall not be used in exterior applications