Installation Guide

ManualsBrandsJames Hardie ManualsBacker Board0.42-in x 36-in x 60-in Fiber Cement Backer Board

English | 6

COUNTERTOP INSTALLATION

1 | Ensure the cabinets are level and secure

• Use minimum 1/2 in. thick exterior grade plywood subbase or equivalent,

positioned across the wood cabinet. Space between plywood supports

is not to exceed 16 in. on center.

2 | Determine the HardieBacker

Cement Board with HydroDefense

™

Technology layout

• Do not align 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 and joints.

3 | Attach the HardieBacker

Cement Board with HydroDefense

™

Technology to the countertop

• HardieBacke

r®

Cement Board with HydroDefense

™

Technology has internal

waterprooﬁng treatment. Does not require a moisture barrier*

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

plywood with a 1/4 in. square-notched trowel.

• Install HardieBacker

Cement Board with HydroDefense

™

Technology.

• Embed cement board ﬁrmly and evenly in the wet mortar.

• Fasten cement board with speciﬁed nails or screws (see “Materials

Required”) a maximum of 8 in. on center over the entire surface.

• Keep fasteners 3/8 in. and 3/4 in. from board edges and 2 in. in from sheet

corners.

• Set fastener heads ﬂush with the surface, without overdriving.

4 | Joints and penetrations

• Seal ﬁxture penetrations, plumbing penetrations and abutments to dissimilar

materials with ﬂexible sealant (see “Materials Required”).

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

(see “Materials Required”). While mortar is still workable, embed 2 in. wide

high-strength alkali-resistant glass ﬁber tape in the mortar and level.

• Do not use all-purpose joint compound or paper tape.

• When complete waterprooﬁng is required, seal all joints, edges and fastener

penetrations with a liquid waterprooﬁng membrane. Follow the liquid

waterprooﬁng membrane manufacturer application instructions.

5 | Exterior Countertop application (limited to HardieBacker

Cement

Board with HydroDefense

™

Technology in HZ10 climate zones

‡

additional details on page 6)

• Follow countertop installation steps 1 through 4.

• DO NOT use mastic (organic adhesives) in exterior applications.

* Some application areas may require additional waterprooﬁng. Refer to local building code requirements.

7 | English

COUNTERTOP DETAIL

Sealant

Tile bonding mortar

Bedding mortar

Fiberglass tape

HardieBacker

Cement Board

with HydroDefense

™

Technology

Wood subbaseTiles

FINISHING WITH A TILE

1. Refer to ANSI A108 and the mortar and tile manufacturers’ published application

guidelines for complete tiling instructions.

2. Wipe the surface of HardieBacker

Cement Board with HydroDefense

™

Technology clean with a damp sponge just prior to adding mastic or mortar.

3. Spread the mastic or mortar with a notched trowel (Note: Please see “Materials

Required” to see which setting material is required for your application).

4. Twist or press and beat in tiles (ceramic tile shall comply with ANSI A137.1).

5. Allow a minimum of 24 hours curing set time before grouting.

FINISHING WITH NATURAL STONE

Natural stone often has hidden weaknesses which can result in surface cracks

in ﬁnished ﬂoors. For best results, always follow the Natural Stone Institute

recommendations (www.naturalstoneinstitute.org).

In addition to the steps outlined under “Wood Floor Installation,” the following is

required:

• The ﬂoor must be engineered not to exceed the L/720 deﬂection criteria,

including live and dead design loads, for the speciﬁc joist spacing used.

• The strength of your natural stone will have an impact on the ultimate

performance of your ﬂooring system. Marble and natural stones must

have sufﬁcient ﬂexural strength for use in ﬂooring systems. James Hardie

recommends using marble or natural stone with a ﬂexural strength of at least

2900 PSI.

English | 8

FINISHING WITH PAINT, WALLPAPER

OR TEXTURE

(Interior application only)

1 | Painting or Wallpapering

Apply a drywall primer suitable for high-moisture areas, as recommended

by the paint manufacturer. Paint HardieBacker

Cement Board with

HydroDefense

™

Technology as you would drywall. If wallpapering, prime

surface of the cement board with a primer suitable for high-moisture areas as

recommended by the wallpaper manufacturer.

2 | Texturing

Texture can be applied to HardieBacker

Cement Board with HydroDefense

™

Technology in the same way as drywall. Follow texture coating manufacturer's

application instructions.

STEAM ROOM APPLICATION

HardieBacker

Cement Board with HydroDefense

™

Technology is recognized for

use in residential steam rooms when installed over conventional framing and in

accordance with HardieBacker

Cement Board installation instructions, TCNA

guidelines (Tile Council of North America Handbook, www.tileusa.com), and

local building codes. Questions and concerns regarding steam room design and

construction should be directed to a knowledgeable professional.

EXTERIOR APPLICATION

Exterior applications are limited to HZ10 product zones. See page 11 for additional

information.

HardieBacker

Cement Board with HydroDefense

™

Technology may be used up

to a height not exceeding the lesser of: through the second-story above grade or

30 ft. above grade. The product must be installed over sub-sheathing with a code

approved water-resistive barrier, or in accordance with the applicable code. Install

ﬂashings, clearances, and other building practices per local code. James Hardie

will assume no responsibility for water inﬁltration. Fasteners: Use a minimum

No.11 ga. 1-3/4 in. long rooﬁng nails or No. 8 1-3/4 in. long 0.375 in HD or

ribbed wafer head corrosion resistant screws spaced a maximum of 8 in. OC into

supports.

The maximum weight of the overlayment (tiles, stones and veneers) is not to

exceed the code limit of 15 lbs/sq ft. Follow installation procedure in accordance

with the stone and mortar manufacturer’s recommendations. Stones must be free

of any substance that may impede proper adhesion. Skim coat is recommended

to be 1/8 in. – 1/4 in. thick and the tile/stone is to be installed while the skim coat

is wet.

CAUTIONS: Do not use HardieBacker

Cement Board with HydroDefense

™

Technology in any of the following applications:

• As a backer board in balcony railings and balcony parapet walls.

• Installed to a height exceeding through the second story above grade or

greater than 30 ft. above grade.