CB237 - DUROCK® Brand Cement Board Installation Guide

DUROCK

Brand

Cement Board

installation

guide

Substrate and ceramic tile

installation for walls,

ﬂoors, countertops and

wall shields.

A ceramic tile installation is only as good as

the surface beneath the tile. Strong, lightweight

and resistant to water damage, DUROCK

Brand

Cement Board is an ideal base for ceramic tile

installations throughout the home.

Installing tile takes planning, time and care.

But with the help of this step-by-step installation

guide, the careful do-it-yourselfer can get the

same results as a professional.

DUROCK

Brand Cement Board...

Strength beneath the surface

™

Textured side

Coated

glass-ﬁber

mesh

Aggregated

portland

cement core

Smooth wrapped edge

Smooth side

Cut edge

ToolsStart with Quality

Products

In general, common tools are used

for cement board installation while

installing tile requires special tools.

Retail stores frequently rent the

special tools needed for tile work on

a per-day basis, including tile cutter,

nippers and notched trowels. Other

tools you may need for cement

board and tile installations include:

straightedge, level, tape measure,

caulk and caulking gun, hammer,

drill, drill bits (including hole-saw

bits), wood rasp, scoring tool or

utility knife, sponge and squeegee.

UROCK Brand Cement Board

Standard board is 1/2 or 5/8 thick

and 32,3 or 4 wide. Standard

lengths are 4,5,6 or 8. Custom

lengths are available upon request

and minimum order requirements

do apply. D

UROCK

Brand Underlay-

ment is 4x4x5/16,3x5x5/16

or 4x8x5/16—ideal for ﬂoor and

countertop jobs.

Board is smooth on one side for

adhesive applications, textured

on the other for thin-set mortar

applications.

UROCK

™

Brand Interior Tape

Alkali-resistant glass ﬁber tape

reinforces interior cement board

joints to provide a strong, continu-

ous surface.

Fasteners

Cement board is readily applied

over framing with 1-1/2 hot-

dipped galvanized rooﬁng nails

or 1-1/4 D

UROCK

™

Brand Wood

Screws. With steel framing

use 1-1/4 D

UROCK

™

Brand

Steel Screws.

Adhesives, Mortars, Grouts

Check your local tile distributor for

the products available and which

ones are appropriate for your job.

Installing Board—

Walls and Ceilings

A typical tub surround uses two

3x5 cement boards horizontally

for tub backwall, one 3x6 board

vertically at each endwall, and

one 3x5 board for the ceiling.

1. Cutting

To cut D

UROCK Brand Cement

Board, mark desired size on the

board with a rule and pencil.

Score both sides and edges

with a utility knife through the

glass-ﬁber mesh, and snap the

board to size. Smooth cut

edges with wood rasp. Cutting

with a circular saw with a car-

bide-tipped blade is an alterna-

tive.

2. Cutouts

To make cutouts for ﬁxtures,

outline area with utility knife, cut

through the mesh on both sides,

and punch out with a hammer

from the back side. Smooth

edges with wood rasp.

Alternatively, mark location and

drill hole using the appropriate

size hole-saw bit and drill. Use

slow speed if available.

3. Attachment

Place a 1/4 spacer strip or

shim around lip of tub or shower

pan to hold bottom edge of

cement board off lip.

Fasten board to wood studs

spaced at 16 o.c.* with 1-1/2

hot-dipped galvanized rooﬁng

nails spaced 8 o.c. for walls,6

o.c. for ceilings, or using 1-1/4

UROCK Brand Wood Screws

with the same spacing.

(For steel stud applications, use

1-1/4 D

UROCK Brand Steel

Screws.) Leave a 1/8 gap

between all panel edges.

*On center is the spacing between the

centerlines of two structural members or

fasteners.

Installing Board—

Floors

1. Lamination

Laminate 5/16 D

UROCK Brand

Underlayment to minimum 5/8

thick exterior grade plywood or

oriented strand board (OSB)

using adhesive or mortar

suitable for bonding cement

backer board to the subﬂoor.

Apply adhesive with 5/8

V-notched trowel, mortar with

1/4 square-notched trowel.

2. Fasteners

Place underlayment with joints

staggered from subﬂoor joints.

Fit ends and edges closely but

not forced together, leaving a

1/8 gap. Fasten underlayment

to subﬂoor with 1-1/2 hot-

dipped galvanized rooﬁng nails

or 1-1/4 D

UROCK Brand Wood

Screws spaced 8 o.c. in both

directions.

When 1/2” or 5/8” D

UROCK

Brand Cement Board is used

in underlayment applications,

follow the same procedure as

for 5/16” D

UROCK Brand

Underlayment.

1. Attachment

Install minimum 3/4 exterior-

grade plywood or OSB base

across the wood cabinet sup-

ports. Position ends and edges

over supports. Staple-attach

15-lb. felt or 4-mil polyethylene

ﬁlm using 1/4 galvanized sta-

ples over the plywood base.

Fasten to the plywood with

1-1/4 D

UROCK Brand Wood

Screws or 1-1/2 hot-dipped

galvanized rooﬁng nails, spaced

8 o.c. in both directions and

around edges. Leave a 1/8

gap between panels.

When using 1/2 or 5/8 D

UROCK

Brand Cement Board in under-

layment applications, follow the

same procedure as for 5/16

UROCK Brand Underlayment.

Installing Board—

Countertops

Installing Tile—

Measuring and Planning

Preﬁll joints, as well as inside and

outside corners, with latex-forti-

ﬁed mortar or Type 1 organic

adhesive and then immediately

embed tape and level joints.

NOTE: Use latex-fortiﬁed portland cement

mortar for wall shield and ﬂoor protector

applications.

Joint Treatment—Walls,

Floors and Countertops

1. Walls

Establish tile height for walls by

ﬁnding the low point of the ﬂoor

next to the wall. Measure from

this point to wainscot height

including base and cap. On new

work where ﬂoor must be

installed, allow for tile thickness.

From low point, stack one row of

tile to required height with dabs

of mastic on the back of each

tile. Use cap to establish height

but draw line on top of the last

tile as caps can be installed

later.

Find vertical starting line by

beginning from the center of the

wall. Lay out a row of tile to the

corner. If cut comes to less than

half the tile, adjust vertical start-

ing line so its center hits middle

of tile instead of tile joint.

2. Floors

Find starting point for ﬂoors by

placing tile on ﬂoor in front of

the tub and along the adjoining

wall. Some tile may have to be

cut to ﬁll in open spaces. Fit tiles

to pipes, then draw starting line

for adhesive.

3. Setting tile

To set tile, apply the adhesive

or mortar you’ve selected to

wall, ﬂoor or counter top using

notched trowel, holding at 50°

or 60° angle for walls.

Working a small area at a time,

set tile with a slight sliding

motion and press into place.

This avoids adhesive pile-up on

tile edge and in grout space.

Keep tiles aligned so joints are

straight and uniform.

Use tile spacers, if desired.

If adhesive is squeezed from

under tile, you’re using too

much. Clean out excess

adhesive before it dries.

Maintain 1/4 shims beneath

the bottom row of tiles and

cement board to make a caulk

joint along tub rim.

When beginning at the top,

place tile to horizontal line, then

butter each cap and place in

position.This eliminates possi-

bility of troweling adhesive

above required height.

4. Cutting Tile

To trim tile use a professional

tile cutting tool. Score tile only

once for each cut.This prevents

uneven breaking of tile and

dulling of cutting wheel.

To make contoured and irregular

cuts, use nippers to take small

bites to prevent cracking or

breaking of tile.With rod saw

use long, even strokes to avoid

binding. Smooth cut edges with

an abrasive stone.

1. Application of Grout

on Walls

Wait at least 24 hours after tile

has been installed before grout-

ing.Apply with a rubber ﬂoat or

squeegee at a slight angle to

the walls. Go over each joint

three times, spreading grout

across tile diagonally.

Fill joints completely. Remove

excess grout with a ﬂoat or

squeegee as you go along.

Grouting

Let grout set for 20 minutes,

then wipe tile diagonally with a

damp square-edge sponge.

Continue until grout lines are

even and joints are smooth.

Rinse sponge often but keep it

as dry as possible. Let joints dry

about 15 to 20 minutes, or until

a haze forms on the tile.Then

polish with clean paper towel or

a clean white cloth.

Caulking

2. Application of Grout on

Floors and Countertops

Wait at least 48 hours after

the tile has been installed

before grouting. Apply grout

and force into joints with rub-

ber ﬂoat. Remove excess

grout by drawing ﬂoat across

tile at 45° angle. Then wipe

tile diagonally with damp

sponge until joints are smooth

and even. Rinse sponge often,

and wring it as dry as possi-

ble. Polish with clean paper

towels or a clean, white cloth.

NOTE: After you’ve completed grout-

ing, it’s important to put moisture back

into the grout for a few days for

stronger grout joints. Dampen grout

now and then with a ﬁne water spray

during the ﬁrst 24 hours while grout is

curing. After the ﬁnal cure—in about 2

or 3 weeks—protect grout surface on

walls from dirt by coating with silicone

tile and grout sealer. Do not use sealer

on ﬂoors.

Walls

Fill 1/4 space between tub lip

and bottom edge of tile around tub

with ﬂexible sealant. Also caulk

around tub soap dish and other

wall ﬁxtures. Fill vertical grout

lines adjacent to door jambs with

ﬂexible caulk rather than stiff

cement grout.

Floors

Caulk space where ﬂoor edges

meet walls with sealant. Protect

unglazed mosaic or quarry tile

with a sealer.

Countertops

Follow the same steps used for

grouting ﬂoors. Caulk abutments

of countertop and walls and, if

needed, underneath sink edge.

Floor Protectors

Apply 1/8 to 1/4 thick latex-

fortiﬁed portland cement to solid

surface—never on top of

carpeting or padding.

Fasten D

UROCK Brand Cement

Board with 1-1/4 hot-dipped

galvanized rooﬁng nails or 1-1/4

UROCK Brand Screws, spaced 8

o.c. in both directions, penetrating

floor a minimum of 3/4.

Other Applications of

Cement Board

Wall Shields

Cut 1/2 D

UROCK Brand Cement

Board to panel and furring strip

sizes with carbide-tip scoring tool.

Smooth rough edges with wood

rasp.

Fasten furring strips to framing

with 1-1/2 hot-dipped galvanized

rooﬁng nails spaced 8 o.c. Fasten

wall shield through furring to

framing with 2-3/4 nails 8 o.c.

Maintain 3/4 minimum framing

penetration for both furring and

shield.

For additional information on wall

shields and ﬂoor protectors, see

the D

UROCK Brand Cement Board

Submittal Sheet, CB198.

Manufactured by

United States Gypsum Company

125 South Franklin Street

Chicago, IL 60606

Trademarks

The following trademark used

herein is owned by United States

Gypsum Company: D

UROCK,

TRENGTH BENEATH THE SURFACE.

Notice

We shall not be liable for incidental

and consequential damages,

directly or indirectly sustained, nor

for any loss caused by application

of these goods not in accordance

with current printed instructions or

for other than the intended use.

Our liability is expressly limited to

replacement of defective goods.

Any claim shall be deemed waived

unless made in writing to us within

thirty (30) days from date it was or

reasonably should have been

discovered.

CB237/rev. 3-02

Printed in U.S.A.

Safety First!

Follow good safety and industrial

hygiene practices during handling

and installing of all products and

systems.Take necessary precau-

tions and wear the appropriate

personal protective equipment as

needed. Read material safety data

sheets and related literature on

products before speciﬁcation

and/or installation.

For warranty or product information

and literature:

(800) USG-4YOU (874-4968)

http://www.usg.com