Installation Instructions

STONE INSTALLATION INSTRUCTIONS

LATH INSTALLATION

Where lath is required, it shall be installed in accordance with ASTM C1063. Typically this will require corrosion resistant

fasteners every 6" on center vertically, and 16" on center horizontally, fastened to framing. If an alternative lath is used,

install it in accordance with the manufacturer’s installation instructions and evaluation report. See the following Material

Selection section for more specific lath requirements.

Note: Fasteners installed between framing should be limited as they may extend into the wall’s insulation cavity.

SCRATCH COAT

Using a trowel or spray application, install mortar scratch coat of minimum

thickness of ½" up to ¾." Use sufficient material and pressure to fully engage and

encapsulate the lath. No lath material should be visible after scratch coat

installation.

Note: Proper encapsulation and scratch coat thickness are key aspects to lath

corrosion resistance and physical performance characteristics.

STEP THREE:

MATERIAL SELECTION

WATER RESISTIVE BARRIER (WRB)

Select a material meeting one or more of the following standards:

• ASTM D226 Type 1 No.15 Asphalt Felt, intended for wall application

• ASTM E2556/E2556M

• ICC ES AC-38. Current Evaluation Report, by an ANSI accredited evaluation service, showing

compliance to ICC ES Acceptance Criteria #38

• Liquid WRB/Air Barrier–Current Evaluation Report by an ANSI accredited evaluation service showing

compliance to code requirements for WRB

LATH

Select a material meeting one or more of the following standards:

• ASTM C847, minimum 2.5 lb/yard expanded metal lath

•

ASTM C847, minimum 3.4 lb/yard, 3⁄8" rib, expanded metal lath

• ASTM C1032, minimum 18 gauge, woven wire mesh

• ASTM C933, welded wire lath

• Non-metallic lath, with a current evaluation report, confirming compliance to ICC-ES AC 275 by an ANSI

accredited evaluation service, confirming alternative to one of the above lath products

All lath products must be self-furred, or use furring fasteners, to provide ¼" clearance between lath and substrate, for the

purposes of mortar embedded encapsulating lath.

LATH FASTENERS

Select fasteners that meet the requirements of the following standard:

• ASTM C1063

1. Galvanized nails, staples, concrete nails. Penetration depth into wood framing is ¾" minimum.

2. Corrosion-resistant, self-drilling, self-tapping pancake-head screw with 7⁄16" head, of 1¼" length or

suitable to obtain 3⁄8" penetration beyond inside surface of metal. (Used for installing to metal surfaces

such as metal studs or metal building siding.)

MORTAR

Select a material meeting one or more of the following standards:

• ASTM C270 Type N or Type S

• ASTM C1714 Type N or Type S

• ANSI A118.1 or A118.4