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	Introduction
	Guide Specifications
	Stucco Details
	Quality Assurance
	Compliance Reports
	Plaster Thickness Tables
	Scope of Work
	Texture / Colors

Guide Specifications

Part I:General
1.01 Scope
This specification covers the minimum requirements for the application of a stucco
system, including general information pertaining to the design and application of stucco.

NOTE:
• This specification serves as a guide for the development of a specification
for a particular project.

1.02 Contractor Scope of Work
The work of this section includes all the equipment, materials and labor necessary to
complete a stucco system, as indicated in this Stucco Resource Guide and/or in project
documents (drawings and specifications).

1.03 Related Sections (Section numbers may be different depending upon specification format)

A. Section 01200 — Project Meetings
B. Section 01630 — Substitutions

NOTE:

• Product substitutions will be considered only under the terms and
conditions of section 01630.

C. Section 03300 — Concrete
D. Section 04220 — Unit Masonry
E. Section 05410 — Load-Bearing Steel Studs
F. Section 06110 — Wood Framing
G. Section 07240 — Exterior Insulation and Finish Systems
H. Section 07600 — Flashing and Sheet Metal
I. Section 07900 — Joint Sealants
J. Section 09110 — Non-Load-Bearing Steel Studs
K. Section 09250 — Gypsum Sheathing Board
L. Section 09900 — Painting

Details in this Stucco Resource Guide may show a single layer of water-resistant
barrier for drawing clarity only. Refer to the Guide Specification
section 3.38-B. The recommendation is for two layers.

1.04 Reference Standards

A. National Building Code — Canada
B. City Building Code — Vancouver, B.C.
C. Building Codes - International, NFRA, California, Uniform
D. Stucco Resource Guide (NWCB)
E. American Concrete Institute ACI 524R: Guide to Portland Cement Plastering
F. Federal Specifications FS UU-B-790a: Building Papers, FS FF-N-105B: Nails, Wire Staples for Application of Gypsum Board, FS QQ-W-461H: Wire, Steel and Carbon (round , bare & coated)
G. Portland Cement Plaster (Stucco) Manual by PCA
H. ASTM Standards

ASTM A526: Steel Sheet, Hot-Dip Galvanized, Commercial Quality
ASTM C91: Masonry Cement
ASTM C144: Aggregate
ASTM C150: Portland Cement
ASTM C1328: Plastic Cement
ASTM C206: Hydrated Lime
ASTM C260: Air-Entraining Admixtures
ASTM C494: Chemical Admixtures for Concrete
ASTM C841: Installation of Interior Lathing and Furring
ASTM C847: Metal Lath
ASTM C897: Aggregate for Job-Mixed Portland Cement Plaster
ASTM C926: Application of Portland Cement-Based Plaster
ASTM C932: Surface-Applied Bonding Agents for Exterior Plastering
ASTM C979: Pigments for Integrally Colored Concrete
ASTM C1032: Woven Wire Plaster Base
ASTM C1063: Installation of Lathing and Furring for Portland Cement Plaster
ASTM D1784: Rigid Poly (Vinyl Chloride) PVC Compounds

I. NAAMA Standard ML/SFA 920

NOTE:
• Current editions at date of bid.
• Use references and standards applicable to project.

1.05 Standards for Work
All work to be performed per Northwest Wall and Ceiling Bureau recommendations.
A. Stucco Resource Guide and project construction documents.

NOTE:
• Project construction documents to indicate type of stucco assembly.
(Refer to “Stucco Assemblies” section of this Stucco Resource Guide).

1.06 Submittals

A. Submittal requirements by the stucco contractor are to be indicated in the construc-tion documents. The following is a list of documents that may be requested.

1. Product literature.
2. Samples and/or mock-ups of system.
3. Certification of compliance of materials and/or product literature.
4. Product literature for all additives and proprietary components.
5. Finish sample for texture and color for architect/owner approval.

NOTE:
• Delete submittals not required.
• Plastering contractor is not to proceed with work until the required
submittals have been approved.

1.07 Quality Assurance for Scope of Stucco Work

A. Pre-installation meeting.
B. Wall assembly fire-resistance rating: _______ hour(s).

NOTE:
• Construction documents shall indicate the type of fire and/or sound
assembly rating required for project.
• Construction documents to indicate fire-resistance assembly test
required.

C. “Scope of Work Responsibilities Tables” section of this Stucco Resource Guide.
D. “Stucco Quality Assurance Checklist” section of this Stucco Resource Guide.
E. If required and feasible, an approved finish coat on a portion of the building.
Location of finish coat sample as directed by the architect.

NOTE:
• Delete if not applicable.

F. Applicator qualifications. The plastering company shall meet the following
requirements:

1. Specialize in this scope of work.
2. Have qualified and properly trained people to perform work.
3. Be licensed, bonded and insured.
4. Be in good financial standing and capable of meeting the financial obligations
associated with the stucco scope of work on the project.
5. Have documented experience in quality work of comparable scope.
6. Be recommended as a qualified installer by NWCB or national or regional Wall
and Ceiling Association (Plastering Association) or approved by architect prior
to bid.
7. Contractor shall be able to meet schedule requirements set at time of bid.

1.08 Delivery, Storage, Handling and Setup

A. Materials at job site to be in original containers with labels intact and legible.

NOTE:
• Exception: Basecoat sand

B. All trim accessories and lath and/or other specified products to be shipped to job site
in original containers. Any damaged or bent materials shall be replaced.
C. All sack materials to be stored above ground, dry and protected.

NOTE:
• General contractor shall provide suitable site for delivery, storage and
handling of materials.
• General contractor shall provide suitable site for plastering operation.

1.09 Environmental Conditions

A. Cold Weather Conditions:

1. Do not apply cement plaster when ambient temperature is less than 35....F (2....C).
2. Do not apply cement plaster to any frozen surfaces or surfaces containing frost.
Protect plaster coats against freezing for a period of 24 hours after application.
3. Do not use frozen materials.
4. Hoarding (tenting), heat and ventilation must be provided if cement plastering
is done in a temperature below 35....F (2....C).

NOTE:
• The plastering contractor is not responsible for these requirements.
• Maintain adequate ventilation. Vent heaters to outside.

5. Admixtures of cement plaster for cold weather condition must be approved and
used in accordance of manufacturer’s recommendations.

B. Warm Weather Conditions:

1. Protect the basecoats and finish coat of cement plaster from uneven and
excessive evaporation in warm, windy weather. (Refer to section on curing in
Part III)

NOTE:
• Moist-curing is recommended.

Part II:Products

2.01 Weather-Barrier Backing/Water-Resistant Barrier

A. Water-resistant paper—Federal Specification UU-B-790a, grade D/30-minute or 60-
minute
B. Spunbonded olefin housewrap manufactured and designed specifically for stucco.
C. Flashing material around rough wall openings shall be a reinforced coated vapor-barrier,
grade A or B product, sheet metal, PVC plastic, or other approved
membrane. The application of the flashing is not the responsibility of the stucco contractor. Refer to the “Scope of Work Responsibilities” section of this Stucco
Resource Guide.

2.02 Window head, door, louver and/or other penetration-plus wall opening pan-type flashing - 26-gauge galvanized sheet metal, or PVC plastic.

NOTE:
• Construction documents to indicate responsibility for installation of
window head flashing and other stucco component flashing.

2.03 Tie Wire

Hanger and tie wire to be galvanized and annealed low-carbon steel:
FSQQ-W-461g. AS
A. Hanger wire No. 8—.1620 inch (4.12 mm)
B. Tie wire 18 gauge—.0475 inch (1.22 mm)
C. Tie wire 16 gauge—.0625 inch (1.59 mm)

2.04 Runner- and Cross-Furring Channels

Cold-rolled galvanized steel channels, 1 1/2 inches (38 mm) and 3/4 inches (19 mm), a
minimum of 33,000 psi yield strength and a minimum of .0538-inch bare steel thickness,
ASTM A526.

NOTE:
• Suspended soffits/ceilings—1 1/2-inch (38 mm) main runner, 3/4-inch (19
mm) cross furring.

2.05 Furring “Hat” Channels
Furring channel, galvanized 7/8-inch (22 mm), 20-gauge.

2.06 Fasteners Shall Comply with:
A. Nails—FS FF-N-105
B. Staples—FS FF-N-105
C. Screws—ASTM C 646
D. Power-driven fasteners—per building code approval

NOTE:
• All fasteners to be corrosion-resistant and new.

2.07 Lath

NOTE:
• Architect/specifier to indicate in construction documents the type or
types of lath (A, B, C or D). Delete types of lath not applicable.
• Self-furring paperback lath (a combination of lath and grade D 60-
minute water-resistant barrier) is not recommended over a vertical
concrete or concrete masonry surface if the construction documents.
require a water-resistant barrier for these surfaces.
A. Self-furring woven wire lath 17 gauge—1 1/2-inch (38 mm) opening, galvanized.
Shall comply with ASTM 1032.

NOTE:
• For vertical surfaces only.
B. Self-furring diamond-mesh metal lath galvanized, 2.5 or 3.4 pounds per square yard.
Shall comply with ASTM 847.

NOTE:
• 2.5-pound-per-square-yard self-furring lath may be used for a sheathed
framing construction system, 16 inches (400 mm) o.c., or for attachment
directly to concrete or concrete masonry.

C. Self-furring welded wire lath, 16 gauge wire, galvanized openings not to exceed 2
inches x 2 inches (50 mm x 50 mm). Shall comply with ASTM 933.

NOTE:
• For vertical surfaces only.
D. 3/8-inch (10 mm) rib lath, galvanized. ASTM 847

NOTE:
• For soffit condition with open-frame construction, with supports 24
inches (600 mm) o.c.

2.08 Trim Accessories

NOTE:
• Trim Accessories shall be fabricated from galvanized steel, zinc (alloy),
PVC or anodized aluminum.
• Depth (the grounds) of accessories depends on the required thickness of
cement plaster basecoat, without the finish coat.
• If the construction documents do not indicate the type of accessories to
be installed, the plastering contractor shall select the accessories in
accordance with these standards.
• Accessories of PVC plastic or zinc (alloy) are recommended if corrosion
is a concern because of environmental conditions.
• Accessories with a finish surface lip flange and/or embedment flange to
key into cement plaster are recommended.
• It is recommended that PVC or aluminum reveals, when used in
conjunction with 2-inch x 2-inch welded wire lath, incorporate a strip of
expanded metal lath over the solid reveal flanges.

A. Steel accessories per ASTM C 841
B. PVC plastic accessories per ASTM D 1784 & C 1063
C. Aluminum accessories from extruded alloy 6063 T5
D. General types of accessories:

1. Foundation weep screed: ______________________________________
2. Casing bead type no. 66 (JMOLD): _______________________________
3. Corner reinforcement (corner bead): ______________________________

NOTE:
• No. 1A expanded corner beads for interior gypsum plaster are not
recommended.
E. Soffit vents ______________________________
F. Drip screeds ______________________________
G. Trim accessory joints (control joints), expansion joints, or revels____________

NOTE:
• Construction documents shall reference type, style and manufacturers of
accessories.
• Delete accessories not applicable for the project.

2.09 Bonding Agents
Bonding agents must conform to ASTM C 932, nonoxidizing, non-crystallizing,
non-re-emulsifiable.

NOTE:
• Apply per manufacturer’s recommendations.
• Apply bonding agents only to clean, structurally sound surfaces
(concrete, concrete masonry and cement plaster).
• Indicate manufacturer and brand name.
• Delete if not applicable.

2.10 Plaster Materials

NOTE:
• Delete cements not applicable.
A. Stucco basecoat

1. Portland Cement: ASTM C 150 Type I or Type I/II
2. Masonry Cement: ASTM C 91 Type I or Type I/II
3. 1-P Portland Cement: ASTM C 595
4. Manufactured basecoat cement for stucco

NOTE:
• Indicate manufacturer as per NWCB and/or regional wall and ceiling
association recommendation.
B. Hydrated lime: ASTM C 206 Type S
C. Stucco finish

1. White portland cement, ASTM 150 Type I or Type I/II
2. Regular portland cement, ASTM 150 Type I or Type I/II
3. Manufactured stucco finish

NOTE:
• Indicate manufacturer as per NWCB and/or regional wall and ceiling
association recommendation.

NOTE:
• Do not use frozen aggregate.
A. Basecoat sand

NOTE:
• ASTM C144 or C897
• Natural or manufactured
• Washed and free of deleterious materials
• Locally available sand that approximates ASTM C144 or C897, but
which may be nonconforming, can be approved for use if past perfor-mance
indicates that it is an appropriate material.
B. Finish coat sand

NOTE:
• ASTM C897
• Natural or manufactured
• Freshwater washed and free of deleterious materials
• Locally available sand that approximates ASTM C144 or C897, but
which may be nonconforming, can be approved for use if past perfor-mance
indicates that it is an appropriate material.

2.12 Water Potable, clean, free from impurities.

2.13 Admixtures

NOTE:
• No household-type detergents or chlorides shall be permitted.
• Only admixtures manufactured specifically and approved for use in a
stucco mix shall be permitted.
• Admixtures without supporting documentation and appropriate testing
or industry performance will not be approved by the NWCB and/or
regional wall and ceiling association.
A. Fibers: 1/2-inch (13 mm) long, ASTM C 1116

NOTE:
• Recommended as part of basic basecoat mix.
• Only in basecoats, not in finish coat.
• Polypropylene, nylon or alkali-resistant glass fibers.
• Use only types specifically manufactured for a stucco basecoat and per
manufacturer’s recommendations.

B. Air-entraining admixtures:

NOTE:
• ASTM C 260
• Amount used shall be consistent with manufacturer’s recommendations.
• Use only products approved by the NWCB and/or regional wall and
ceiling association.
C. Water-reducing admixtures

NOTE:
• ASTM C494, Type A
• Amount used shall be consistent with manufacturer’s recommendations.
• Use only products approved by the NWCB and/or regional wall and
ceiling association.
D. Accelerating admixtures

NOTE:
• ASTM C494, Type C and E.
• Must be non-chloride or chloride with rust-inhibitors.
• Amount used shall be consistent with manufacturer’s recommendations.
• Use only products approved by the NWCB and/or regional wall and
ceiling association.
E. Pump-aid admixtures

NOTE:
• Amount used to be consistent with manufacturer’s recommendations.
• Use only products approved by the NWCB and/or regional wall and
ceiling association.

2.14 Coloring Compounds for Job-site Stucco Finish

NOTE:
• Delete if not required.
• “A” prepackaged colors recommended rather than “B” raw color
pigments.
A. Prepackaged colors

NOTE:
• ASTM C979
• Use only coloring compounds manufactured for a job-site stucco finish.
• Identify manufacturer, brand name and color code.
• Mix with finish coat materials according to manufacturer’s recommen-dations.
• Best color uniformity can be achieved with prepackaged products.
B. Raw Color Pigments

NOTE:
• ASTM C979
• Natural or synthetic iron oxides
• Identify manufacturer, brand name and color code.
• Mix with finish coat materials in proportions which replicate a
previously approved sample.
• Variation in the uniformity of color is normal when raw pigments are used.

2.15 Mix Proportions

NOTE:
• Proportions are parts by volume for basecoats and job-site stucco finish
coat.
• Use standard measuring devices and know volumes for all materials.
• Sequential batches to be proportionally alike.
• All mixing in a mechanical mixer.
• Continue to mix for 3-5 minutes after all ingredients have been added.
• Add fibers 2-3 minutes before mixing is complete.
• Factory-prepared stucco finish coat per manufacturer’s requirements.
• Admixtures per manufacturer’s requirements.
• Cement materials shall be based on full bag increments.
• Shovel count can be used for measuring sand if standardized first.
• Use enough water to produce suitably plastic cementitious material,
keeping water to a minimum.
• Sequence of materials: (1) water, (2) half of sand, (3) all of the cement
and/or lime, (4) balance of sand and (5) water for workability.
• “Brown” coat may contain the higher volume of sand.
• For integral color finish, factory-prepared finishes will result in truer
and more consistent color.
• Sand per sum of cementitious material.
• For mix no. 1, 3, 4 and 5, volume of sand in first coat shall the same or
less than volume in the second (brown) coat, not to exceed 4 parts of
sand per sum of cementitious materials.
• For mix no. 2, volume of sand in first coat shall be the same or less than
volume in the second (brown) coat, not to exceed 3 1/2 parts of sand per
sum of cementitious materials.
• Amount of fibers per mix per manufacturer’s recommendations.
A. Basecoat mix parts by volume (ASTM C 926) and finish coat mix parts by volume
(ASTM C926)

NOTE:
• Select one of the five mixes or another approved ASTM C926 mix for the
project. Do not interchange components. Once project has been started,
do not switch to another mix.
• Architect to indicate which one of the five mixes to use. If mix is not
shown in construction documents, plastering contractor may use one of
the five mixes shown in this Guide Specification.
• Delete mixes not to be used in the project.
• Volume of sand per sum of cementitious material.

Mix No. 1—Basecoat
Portland cement .............................. 1
Masonry cement ............................. 1
Sand ............................................ 3 1/2 - 4 1/2
Fibers ............................................ per manufacturer’s recommendations
Mix No. 2—Basecoat
Portland cement .............................. 1
Lime ............................................ 1/4 - 1/2
Sand ............................................ 3-4
Fibers ............................................ per manufacturer’s recommendations
Mix No. 3—Basecoat
1-P portland cement ........................ 1
Masonry cement ............................. 1
Sand ............................................ 3 1/2 - 4 1/2
Fibers ............................................ per manufacturer’s recommendations
Mix No. 4—Basecoat
Plastic cement ................................. 1
Sand ............................................ 3 1/2 - 4 1/2
Fibers ............................................ per manufacturer’s recommendations
Mix No. 5—Basecoat
Portland cement .............................. 1
Plastic cement ................................. 1
Sand ............................................ 3 1/2 - 4 1/2
Fibers ............................................ per manufacturer’s recommendations

B. Job-site stucco finish coat
White portland cement.................... 1
(or regular portland cement)
Lime ............................................ 1 - 2
Sand ............................................ 3

NOTE:
• Add manufactured coloring compounds to job-site stucco finish mix per
manufacturer’s recommendations.
• Delete if not applicable.
C. Manufactured stucco finish

NOTE:
• Mix and apply per manufacturer’s recommendation.
• Manufacturer to be approved by NWCB and/or regional wall and ceiling.

2.16 Acrylic Finish

NOTE:
• A proprietary finish material by EIFS manufacturer, approved by NWCB
and/or regional wall and ceiling association.
• 100-percent acrylic polymer material in finish.
• Mix and apply per manufacturer’s recommendations.
• Delete if not applicable.

Part III:Execution

3.01 Examination
A. Prior to starting lathing or plastering work, carefully inspect installed work of other
trades to verify that work is complete to the point where work of this section may
properly commence.
B. Notify the architect or proper authorities in writing of conditions detrimental to the
proper and timely completion of the lathing and/or plastering work.
C. Do not begin installation until all unsatisfactory conditions are resolved.
D. A pre-construction meeting is recommended with the architect and/or owner, primary
contractor and representatives responsible for the windows, framing, flashing, roofing,
sealants, stucco and any other building components interfacing with the stucco.

NOTE:
• The examination of conditions is the responsibility of all parties involved
in the project.

3.02 Performance
A. The work shall be performed by a skilled and trained work crew.

NOTE:
• Work shall be performed to create a rigid, secure, level or plumb finish
surface, with line dimensions and/or contours as indicated in reference
standards or project documents.

B. Install specified products and/or systems in accordance with reference standards,
manufacturer’s recommendations and this Stucco Resource Guide, unless indicated
otherwise in project documents.
C. Flashings shall be installed prior to start of lathing or may be required to be
integrated at the time of lathing. Flashing is not the scope of work of the contractor
responsible for the stucco assembly.

3.03 Installation of Stucco Trim Accessories

NOTE:
• Refer to details and other portions of this Stucco Resource Guide for
additional information

A. Verify that substrate and work by other trades are complete to the point at which
installation of trim accessories may properly commence.

NOTE:
• Do not begin work until unsatisfactory conditions are resolved.
B. Attachments shall be firm enough to hold trim accessories in place without
misalignment during plastering.

NOTE:
• Flanges or attachment points of trim accessories shall be secured
to substrate in accordance with requirements of manufacturers of
approved fasteners. Space per manufacturer’s directions.
• It is recommended that PVC or aluminum reveals, when used in
conjunction with 2-inch x 2-inch welded wire lath, incorporate a strip of
expanded metal lath over the solid reveal flanges.

C. It is recommended that trim accessories have a small top flange “lip” that goes over
the stucco and/or flange that embeds into the stucco.
D. Zinc alloy or PVC is recommended if trim accessories are exposed to a high-salt
environment.
E. Install individual trim-accessory sections to each other at end joints for accurate
alignment.
F. Install trim accessories in a manner that ensures a true, level and plumb stucco
surface, and moisture resistant.

NOTE:
• Accurate alignment of trim accessories may require shimming, limited to
the thickness of stucco.
• Sections of flashing or trim accessories that butt each other (at corners
or another condition) need to be lapped, caulked, or have a strip of self-adhering
membrane over the joints. This is to prevent moisture from
getting to the building structure.

G. Install the trim accessories in accordance with the required thickness of stucco
basecoat and finish coat requirements. (Refer to Plaster Thickness section)

NOTE:
• Depth (grounds) of trim accessory to be in accordance with the
thickness of stucco. (Refer to Plaster Thickness Tables)
For example, 3/4-inch (19-mm) stucco requires a minimum ground of a
casing bead to be 3/4 inch (19 mm).

H. Install the longest possible lengths of trim accessories. A minimum continuous
section (length) of 7 feet (2 m) is recommended.

3.04 Trim Accessory Joints

NOTE:
• Installation to be in accordance with section 3.03—Installation of
Stucco Trim Accessories.
• Trim accessory joints refer to various types: control joints, expansion
joints, reveals, and/or any other devices or systems that divide (break) the
stucco membrane surface.
• Architect is to select the type of joint and indicate on drawing the
location of joints.
• Trim accessory joints provide relief of stresses from the structure and
cement-plaster curing process.
• Trim accessory joints provide for a plaster stop and a screed.
• Aluminum and/or PVC reveals require that when the lath is installed
over the flange, it totally covers it. The welded wire and woven wire lath
shall be installed so as the crotch of the lath is over the flange.
• It is recommended that PVC or aluminum reveals, when used in
conjunction with 2-inch x 2-inch welded wire lath, incorporate a strip of
expanded metal lath over the reveal flanges.

A. The water-resistant barrier must continue unbroken behind trim accessory joints in
vertical or horizontal direction.

B. Locate to trim accessory joints strategically at points where building movement is
anticipated.

1. Wall penetrations
2. Structural plate lines
3. Junctures of dissimilar substrates
4. Existing construction joints in structure
5. Columns
6. Cantilevered areas

C. Joints are recommended in stucco assemblies with lath reinforcement but have
limited use in direct-applied stucco over concrete or concrete masonry surface.
D. It is recommended that trim accessory joints be weather-sealed by embedment in
caulking at intersections when placed end-to-end and at the terminations.
E. It is recommended to install vertical joints continuously and to abut horizontal joints
to vertical (be sure that water-resistant barrier runs continuously behind joints).

NOTE:
• The use of horizontal reveals, flashing designs and/or other horizontal
surface breaks may prevent continuous vertical joints.
• Expansion joints govern over control joints.

F. Install longest possible lengths. No termination of a section within 24 inches (600
mm) of an intersection, with the exception of pre-manufactured trim accessory joint
intersections.

G. It is recommended that trim accessory joints be installed on framed, sheathed
construction so as to create stucco panel of 150 to 180 square feet (14 m 2 to 17 m 2 )
in as square a configuration as possible.

NOTE:
• Maximum recommended length of a panel is 18 feet (5.5 m). Panel size
approximately 3-to-1 ratio.

H. It is recommended that trim accessory joints be installed with concrete or concrete
masonry construction so as to create a stucco assembly (with lath reinforcement) of
200 to 250 square feet (18 m 2 to 23 m 2 ).
I. Installing control joints over continuous lath is an approved method.

NOTE:
• Control joint is a one-piece trim accessory.
• Control joint may be installed in the “field of panel” only if there is
framing or wood sheathing continuous substrate behind it for attachment.
• Control joints to be wire tied to lath with 18-gauge tie wire (recom-mended
method when lath goes over sheathing board other than wood).

J. The recommendation for the installation of expansion joints or reveals is to break the
lath and lap it over on top of each of the flanges.

NOTE:
• Control joints may also serve as expansion joints, if so specified and
detailed.
• Expansion joints and/or reveals may consist of one or two pieces.
• Control joints are limited in their degree of movement. Two-piece
expansion joints provide greater movement.
K. Sheathed framed construction with vertical trim accessory joints that require the lath
to be terminated (cut) and installed on top of the flanges shall be placed at framing
member locations. Lath shall be attached with appropriate fasteners through the
trim accessory flange, sheathing and into the framing member.

NOTE:
• The lath/flange on each side of the trim accessory joint to be attached to
a framing member. Double framing supports would be required at these
locations.
• This condition does not pertain to control joints installed over continu-ous
lath.

3.05 Lathing for Soffits

A. Suspended soffits/ceilings shall be erected so that the finished basecoat cement
plaster surface is true to line and level, with allowable tolerance of 1/4 inch (6 mm)
in 10 feet (3.1 m)

NOTE:
• Construction documents shall indicate the approximate amount of
deflection of structure to which suspended soffit is attached..34 Northwest
• No attachment of soffit/ceiling abutting to walls or fascia (in order to
prevent transfer of stresses).
• Vertical compression struts to withstand upward wind pressures are not
required unless indicated in project documents.
• NWCB recommends a soffit framing system with sheathing (refer to
3.06-B) because it incorporates a gypsum sheathing board attached to
furring “hat” channels. This type of assembly produces a better stucco
soffit. The sheathing board provides rigidity to the framing system and
helps produce a uniform stucco thickness.
• Refer to sections 3.03 and 3.04.

B. Spacing, attachment, size and type of hangers, fasteners and inserts shall be as
required in reference standards in section 1.04.
NOTE:
• Fasteners and inserts shall have up-to-date testing information from
manufacturers.

3.06 Lathing Systems for Suspended Soffits (for details, see soffit section)

NOTE:
• For additional suspended soffit configurations (size, spans and spacing),
refer to reference standards in section 1.04. (ASTM C1063)
• Construction documents to indicate either the soffit framing system
(refer to 3.06 A) or soffit framing system with sheathing (refer to 3.06 B).

A. Soffit framing system

1. Hanger wires maximum support 16 square feet (1.5 m 2 )
2. 1 1/2-inch (38-mm) main runner channels o.c. spacing 48 inches (1.2 m)
3. 3/4-inch (19-mm) cross-furring channels o.c. spacing 13 to 16 inches (325 to
400 mm)
4. 3.4-pound-per-square-yard diamond-mesh lath
5. Wire-tie lath to cross-furring channels with 18-gauge tie-wire, 6 inches (150
mm) o.c.

B. Soffit framing system with sheathing

1. Hanger wires, maximum support 16 square feet (1.5 m 2 )
2. 1 1/2-inch (38-mm) main runner channels, maximum o.c. spacing 48 inches
(1.2 m)
3. 20-gauge furring “hat” channels, spaced maximum 16 inches (400 mm)
4. 1/2-inch (13-mm) gypsum sheathing board
5. 3.4-pound-per-square-yard self-furring diamond-mesh lath attached through
gypsum sheathing board into furring channels, maximum 6 inches (150 mm)
o.c. with type S screws—wafer head—1 inch (25 mm) long.35 Northwest

3.07 Soffit Lathing System to Wood Joist
A. 3/8 inch (10 mm) rib lath attached 6 inches (150 mm) o.c., with one of the following:

1. Roofing nails: 11 gauge • 7/16-inch diameter head • 1-inch long
2. Staples: 16 gauge • 3/4-inch crown • 1 1/4-inch long
3. Screws: type W • wafer head • 1-inch long

NOTE:
• Fasteners must penetrate into the wood a minimum of 3/4 inch (19 mm)
both legs of staple must penetrate wood. Fasteners to be centered,
minimum 3/8 inch (10 mm) from edge of wood joist.
• Maximum spacing of wood joist 24 inches (600 mm) o.c.

3.08 Application of Stucco Basecoat for Soffits

NOTE:
• Do not use the double-back method of applying the basecoats.
• Verify trim accessories and lath are installed so as to provide proper
screeds, thickness and alignment for plastering.
• Do not begin plastering work until unsatisfactory conditions are resolved.
• Cement plaster can be applied by trowel or machine.
• Apply basecoat to entire horizontal surface and/or section without
interruption or “cold joints.”

A. Indicate the permissible mix number and its proportions to be used for the basecoat

NOTE:
• Delete basecoat mixes not applicable to this project.
• Do not change selected mix or proportions after plastering operation has
started.
• Measurement of ingredients (materials of the mix) to be done with
devices of known volume, accurate, and successive batches proportion-ally
alike.
• Use only enough mix water to make plaster a workable consistency.
• Admixtures to be submitted for approval.
• Basecoat admixtures designed for improving the mix or for enhancing the
plaster application must have been manufactured strictly for that
purpose.
• Admixtures must be accurately measured and used only in accordance
with manufacturer’s recommendations.

B. Apply stucco first (“scratch”) coat in a nominal thickness of 3/8 inch (10 mm). First
coat to completely embed the lath. First coat to be thick enough to allow for scoring
of cement plaster surface. (Refer to Plaster Thickness Tables)

NOTE:
• Scoring of the first coat should be uniform and shallow, approximately 1/
8 inch (3 mm).
C. Moist cure the first (“scratch”) coat for a minimum of 48 hours before application of
the second (“brown”) coat.

NOTE:
• First coat to be hard and rigid before receiving the second coat.
D. Apply stucco second (“brown”) coat in a nominal thickness of 3/8 inch (10 mm)
over stucco first coat. Second coat thickness to bring the combined basecoats (first
and second) thickness to a nominal thickness of 3/4 inch (19 mm). (Refer to Plaster
Thickness Tables)

NOTE:
• Apply second coat over a damp first coat. If required, apply a fine spray
of clean water, so as to dampen only. Do not saturate. Allow water
sheen to disappear before applying the second coat.

E. Apply the second coat with sufficient material and pressure to ensure a tight uniform
bond to the first coat.

NOTE:
• Apply second coat so as not to deform or crack the first coat.

F. Rod the second coat to a true, even plane, filling surface defects with cement plaster.
G. Trowel-float the second coat surface uniformly.

3.09 Curing of Soffit Basecoat—Refer to section 3.40.
NOTE:
• After the second coat has been applied, moist cure it as required, and then
wait a minimum of seven days before the start of finish coat application.
3.10 Stucco Finish Coat—Refer to section 3.41.
3.11 Acrylic Finish Coat—Refer to section 3.42.
3.12 Additional Types of Finishes—Refer to section 3.43.
3.13 Cement Plaster Direct to Concrete

NOTE:
• Concrete to be cured for a minimum of 28 days..37 Northwest
• Not recommended for horizontal surfaces (other than ceilings/soffits).
• Concrete surface to be straight and true, in accordance with standards.
• Concrete surface to be clean, no form release agents, no curing compounds
or other elements in concrete surface preventing a proper bond.
• Concrete should be in good condition and have uniform absorption rate
over entire surface.
• Concrete in poor condition (spalling, delamination, voids) or other
surface defects requires repair before plastering.
• If the concrete surface is not in proper condition, self-furring lath must
be installed.
• If there is any concern about the bondability of the cement plaster direct
to concrete, a test area is recommended. Apply 1/4” - 1/2” thick, by 1’x1’
of cement plaster basecoat to concrete; let it cure for 3 - 4 days. Then try
to remove it. Do this type of test at more than one location.
• Acrylic finish coat is not recommended for concrete retaining walls.
3.14 Stucco “Finish Coat” Direct to Concrete—Refer to “Stucco Wall Assemblies” section
detail A6 in this Stucco Resource Guide.

NOTE:
• The finish coat over concrete is used to enhance the surface appearance;
it is not designed to “true up” the surface.
• Smooth troweled stucco finishes are not recommended because of the
possibility of very fine map cracking. If smooth troweled finish is specified,
surface should be painted with a high-quality acrylic exterior paint.

A. Apply liquid bonding agent directly to concrete surface in accordance with the
recommendation of manufacturer of the material.
B. Application of the stucco finish coat—Refer to section 3.41.

3.15 Acrylic Finish Coat Direct to Concrete—Refer to section 3.42.
NOTE:
• Do not apply finish until all irregularities on the concrete surface have
been corrected.

3.16 Two Coat Stucco Direct to Concrete—Refer to “Stucco Wall Assemblies” section
detail A7 in this Stucco Resource Guide.

NOTE:
• This method provides for an economical way of creating an acceptable
level finished wall surface.
• The system provides a leveling basecoat (brown coat) over the concrete
surface and makes a suitable base for the finish coat with limited total
stucco thickness of 1/2 inch (13 mm).
• Refer to section 3.13..38 Northwest

A. Apply liquid bonding agent directly to concrete surface only in accordance with the
recommendation of manufacturer of the material.
B. Install trim accessories—termination trim accessory, corner reinforcements (corner
beads), trim accessory joints (control joints) and other specified accessories in
accordance with sections 3.03 and 3.04.

NOTE:
• Install per related detail sections of this Stucco Resource Guide.
• Delete trim accessories not applicable.
• Depth (grounds) of trim accessory to be in accordance with the thickness
of stucco. (Refer to Plaster Thickness Tables)
• Install so as to provide the required screed and ground and to create a
true and level surface. (Refer to Plaster Thickness Tables)

C. Trim accessory attachment

NOTE:
• The installation of fasteners and their pullout resistance shall be in
accordance with the manufacturer’s recommendations and safety
requirements.
• If there is any question on the pullout strength of the fasteners, sample
testing on the wall is recommended.
• The psi of the concrete, how long the concrete has cured and the physical
condition of the concrete affect the selection of proper fasteners for the
attachment of trim accessories and lath.
• Fastener head shall be capable of lapping over two or more strands
(recommended to be placed at the crotch of the trim accessory flange)
and/or lapped over attachment hole.
D. Indicate type of stucco termination trim accessory (casing bead):
_________________________________________________________________
Indicate name of manufacturer (optional): _______________________________
E. Attach termination trim accessory to concrete surface with hardened concrete stub
nails; low-velocity, power-actuated pins or drill-and-drive fasteners. Fastener heads
minimum of 3/8-inch (10-mm) diameter, length of fasteners 3/4 inch (19 mm);
spacing of fasteners 8 to 12 inches (200 to 300 mm) o.c.
F. Indicate the type of corner reinforcement (corner bead): _______________________
Indicate name of manufacturer (optional): __________________________________

NOTE:
• Corner reinforcement is recommended at vertical exterior and slanted
corners.

G. Attach corner reinforcement to concrete surface with hardened concrete stub nails;
low-velocity, power-actuated pins or drill-and-drive fasteners. Fastener heads
minimum of 3/8-inch (10-mm) diameter, length of fasteners 3/4 inch ( 19 mm);
spacing of fasteners 12 inches (300 mm) o.c. staggered.
H. Indicate the type of trim accessory joint (control joint, expansion joint, reveal or
other style): __________________________________________________________
Indicate name of manufacturer (optional):__________________________________

NOTE:
• The use of trim accessory joints (control joints) is limited on a stucco
system direct to concrete masonry, and they are not required as
frequently as for framed construction.
• Control or expansion joints are recommended at locations of concrete
expansion joints (construction joints).
• Control joints are recommended if the area exceeds 250 square feet
(23 m 2 ). Panel should be in as square a configuration as possible.
• The location of trim accessory joints and the type are by the architect.

I. Attach trim accessory joints to concrete surface with hardened concrete stub nails;
low-velocity, power-actuated pins or drill-and-drive fasteners. Fastener heads
minimum of 3/8-inch (10-mm) diameter, length of fasteners 3/4 inch (19 mm);
spacing of fasteners 12 inches (300 mm) o.c. staggered.
J. Application of stucco basecoat

NOTE:
• Inspect concrete surface to ensure it is in proper condition for a direct
application of cement plaster.
• Do not begin plastering work until unsatisfactory conditions are
resolved.
• Cement plaster can be applied by trowel or machine.
• Apply basecoat to entire wall panel and/or section without interruption
or “cold joints.”

K. Indicate the permissible mix and its proportions to be used for the basecoat

L. Apply basecoat (brown coat) in a nominal thickness of 3/8 inch (10 mm). Refer to
Plaster Thickness Tables.

NOTE:
• Basecoat direct to concrete 3/8 inch to 1/2 inch (10 to 13 mm) thick, not
greater than 1/2 inch (13 mm)

M. Apply basecoat with sufficient material and pressure to ensure tight contact with
concrete surface and uniform thickness.
N. Rod the basecoat to a true and even plane, filling basecoat surface defects with
cement plaster.
O. Trowel-float the basecoat surface uniformly.

NOTE:
• The floating process densifies the basecoat and provides a proper surface
for the finish coat application.
• Float the basecoat after it has set and when moisture is still present in it.
(The float should not adhere to the surface that is to be worked)
3.17 Curing of Basecoat—Refer to section 3.40.
3.18 Stucco Finish Coat—Refer to section 3.41.
3.19 Acrylic Finish Coat—Refer to section 3.42.
3.20 Additional Types of Finishes—Refer to section 3.43.
3.21 Two-Coat Stucco Direct to Concrete Masonry “CMU”—Refer to “Stucco Wall
Assemblies” section detail A4 in this Stucco Resource Guide.

NOTE:
• This method consists of a leveling basecoat (brown coat) followed by a
finish coat.
• Concrete masonry is an excellent substrate for direct-applied cement plaster.
• The two-coat stucco system trues up the surface, creating a water-resistant
membrane and pleasing finished surface.
• This system is recommended and commonly used over a concrete
masonry substrate or other similar types of surfaces that will develop the
required bond.
• Reinforcement lath is omitted in this system. Do not tool the mortar
joints of the concrete masonry assembly. It is recommended to have
mortar joints struck flush with the surface.
• Concrete masonry wall must have been cured in accordance with
industry standards (a minimum of 30 days) before application of cement
plaster basecoat and carry the designed dead loads before plastering.
• Concrete masonry surface to be clean, no substances on the surface or in
the units and/or joints which would prevent a proper bond with the
stucco basecoat.

• Coated (painted) concrete masonry surfaces require self-furring lath
attached in accordance with standards or the removal of the coating.
• The degree of the masonry wall misalignment will dictate either the
direct application of a two-coat stucco system or the use of self-furring
lath in order to achieve a true wall surface plane.
• Concrete masonry assembly shall be constructed in accordance with its
application standards.

A. Install trim accessories—termination trim accessories (casing beads), corner
reinforcements (corner beads); trim accessory joints (control joints) and other
specified accessories according to sections 3.03 and 3.04 to concrete masonry
substrate.

NOTE:
• Install per related detail sections of this Stucco Resource Guide.
• Delete trim accessories not applicable to project.
• Depth (grounds) of trim accessory shall be in accordance with the
thickness of stucco. (Refer to Plaster Thickness Tables)
• Install so as to provide the required screed and ground in accordance
with a nominal stucco thickness of 1/2 inch (13 mm) and to create a true
and level surface. (Refer to Plaster Thickness Tables)

B. Trim accessory attachment

NOTE:
• The installation of fasteners and their pullout-resistance requirements
shall be in accordance with the manufacturer’s requirements and safety
recommendations.
• If there is any question on the pullout strength of the fasteners, sample
testing on the wall is recommended.
• Fastener head shall be capable of lapping over two or more strands
(recommended to be placed at the crotch of the trim accessory) and/or
lapped over attachment hole.
• Spacing or fasteners depends on type and size of the concrete masonry
units.
• For substrates of concrete masonry units, brick or tile, it is recommended
that the fasteners be placed in the mortar joints. This will minimize
damage to the individual units.

C. Indicate types of termination trim accessories (casing beads):
____________________________________________________________________
Indicate name of manufacturer (optional):__________________________________
D. Attach termination trim accessory to concrete masonry surface with hardened
concrete stub nails; low-velocity, power-actuated pins or drill-and-drive fasteners.
Fastener heads minimum of 3/8-inch (10-mm) diameter, length of fasteners 3/4 inch
(19 mm); spacing of fasteners 8 to 12 inches (200 to 300 mm) o.c.
E. Indicate the type of corner reinforcement (corner bead):_______________________
Indicate name of manufacturer (optional): _________________________________

NOTE:
• Corner reinforcement is recommended at vertical exterior and slanted
corners.
F. Attach corner reinforcement to concrete masonry surface with hardened concrete
stub nails; low-velocity, power-actuated pins or drill-and-drive fasteners. Fastener
heads minimum of 3/8-inch (10-mm) diameter, length of fasteners 3/4 inch ( 19
mm); spacing of fasteners 12 inches (300 mm) o.c. staggered.
G. Indicate the type of trim accessory joint (control joint, expansion joint, reveal or
other style): _________________________________________________________
Indicate name of manufacturer (optional): _________________________________

NOTE:
• Control or expansion joints are recommended at locations of concrete
masonry expansion joints (construction joints).
• The use of trim accessory joints (control joints) is limited on a stucco
system direct to concrete masonry and are not recommended as
frequently as for framed construction.
• Control joints are recommended if the area exceeds 250 square feet
(23 m 2 ). Panel should be in as square a configuration as possible.
• The location of trim accessory joints and the type are by the architect.

H. Attach trim accessory joint to concrete masonry surface with hardened concrete stub
nails; low-velocity, power-actuated pins or drill-and-drive fasteners. Fastener heads
minimum of 3/8-inch (10-mm) diameter, length of fasteners 3/4 inch (19 mm);
spacing of fasteners 12 inches (300 mm) o.c. staggered.
I. Application of stucco basecoat

NOTE:
• Inspect concrete masonry surface to ensure it is in proper condition for a
direct application of cement plaster.
• Do not begin plastering work until unsatisfactory conditions are
resolved.
• Cement plaster can be applied by trowel or machine.
• Apply basecoat to entire wall panel and/or section without interruption
or “cold joints.”

J. Indicate the permissible mix number and its proportions to be used for the basecoat:

K. Apply basecoat (brown coat) in a nominal thickness of 1/2 inch (13 mm). Refer to
Plaster Thickness Tables.

NOTE:
• Basecoat direct to concrete masonry surface 3/8 inch (10 mm) to 5/8 inch
(13 mm) thick, not greater than 5/8 inch (13 mm).

L. Apply basecoat with sufficient material and pressure to ensure tight contact with
concrete masonry surface and uniform thickness.

NOTE:
• Dampen the substrate by spraying with clean water just before starting
plastering.
• It is advisable first to apply a dash bond coat or liquid bonder to the
concrete masonry surface in order to uniform the suction and help
prevent the telegraphing of the mortar joints. Dash coat does not replace
one of the specified number of coats.

M. Rod the basecoat to a true, even plane, filling basecoat surface defects with cement
plaster.
N. Trowel-float the basecoat surface uniformly.

NOTE:
• The floating process densifies the basecoat and provides a proper surface
for the finish coat application.
• Float the basecoat after it has set and when moisture is still present in it.
(The float should not adhere to the surface that is to be worked)
3.22 Curing of Basecoat—Refer to section 3.40.
3.23 Stucco Finish Coat—Refer to section 3.41.
3.24 Acrylic Finish Coat—Refer to section 3.42.
3.25 Additional Types of Finishes—Refer to section 3.43.
3.26 Stucco Assembly Attached to Concrete—Refer to “Stucco Wall Assemblies” section
detail A8 in this Stucco Resource Guide.

NOTE:
• This system is recommended if a greater thickness of stucco is necessary
or if the concrete surface will not provide an adequate bond for direct
application of cement plaster.
• Concrete surface to be in good condition, no large voids, no spalling and
no delamination. Concrete to be true and straight.
• Surface to be within tolerance standards for a concrete tilt-up or poured-in-
place walls.
• Concrete to be cured a minimum of 30 days before start of any stucco
work.
• Do not begin installing trim accessories or lath until all unsatisfactory
conditions are resolved.
• A water-resistant barrier is not required for this stucco assembly. A
combination self-furring lath and water-resistant barrier (paperback
lath) is recommended if the project documents specify a water-resistant
barrier.

A. Install trim accessories—termination trim accessories (casing beads), corner
reinforcements (corner beads), trim accessory joints (control joints) and other
specified accessories in accordance with sections 3.03 and 3.04.

NOTE:
• Install per related detail sections of this Stucco Resource Guide.
• Delete trim accessories not applicable to project.
• Depth (grounds) of trim accessory shall be in accordance with the
thickness of stucco. Refer to Plaster Thickness Tables.
• Install so as to provide the required screed and ground in accordance
with a nominal stucco thickness of 3/4 inch (19 mm) and to create a true
and level surface. (Refer to Plaster Thickness section)
• Install per manufacturer’s recommendations.

B. Trim accessory and lath attachment

NOTE:
• The installation and pullout resistance of fasteners shall be in accor-dance
with manufacturer’s recommendations and safety requirements.
• Fasteners shall be placed in the crotch of the flange and/or the crotch of
the lath.
• The psi of the concrete, how long the concrete has cured and the
physical condition of the concrete affect the selection of proper fasteners
for the attachment of trim accessories and lath.
• If there is any question on the pullout strength of the fasteners, sample
testing on the wall is recommended.
• Bend lath and continue around corners, a minimum of 12 inches (300
mm).

• Apply so as long dimension of lath is horizontal. Apply lath taut.
• Attachment of lath should be at furring points.

C. Indicate type of stucco termination trim accessory (casing bead):
___________________________________________________________________
Indicate name of manufacturer (optional): _________________________________
D. Attach termination trim accessory to concrete surface with low-velocity, power-actuated
pins or drill-and-drive fasteners. Fastener heads minimum of 3/8-inch (10-
mm) diameter, length of fasteners 3/4 inch (19 mm); spacing of fasteners 8 to 12
inches (200 to 300 mm) o.c.
E. Indicate the type of corner reinforcement (corner bead): ______________________
Indicate name of manufacturer (optional): _________________________________

NOTE:
• Selection of proper type in accordance with specified finish coat.
• A welded-wire plastic-nose or PVC corner bead is recommended if finish
coat is a sand-finish stucco or acrylic finish coat.
• Corner reinforcement is recommended at vertical exterior and slanted
corners.

F. Attach corner reinforcement to concrete surface with low-velocity, power-actuated
pins or drill-and-drive fasteners. Fastener heads minimum of 3/8-inch (10-mm)
diameter, length of fasteners 3/4 inch (19 mm); spacing of fasteners 12 inches (300
mm) o.c. staggered, or attach to lath with 18-gauge tie wire, spaced 12 inches (300
mm) o.c. staggered.
G. Indicate the type of trim accessory joint (control joint, expansion joint, reveal or
other style): _________________________________________________________
Indicate name of manufacturer (optional): _________________________________

NOTE:
• Trim accessory joints (control joints) are recommended , but not as
frequently as on framed and sheathed construction. Refer to section 3.04.
• Control joints are recommended for areas greater than 200 square feet
(18 m 2 ). Maximum recommended length of a panel is 20 feet (6 m).
Panel size should not exceed a 3-to-1 ratio.
• The location of trim accessory joints and the type are by the architect.
H. Attach trim accessory joints to concrete surface with low-velocity, power-actuated
pins or drill-and-drive fasteners. Fastener heads minimum of 3/8-inch (10-mm)
diameter, length of fasteners 3/4 inch (19 mm); spacing of fasteners 12 inches (300
mm) o.c.

NOTE:
• Attachment method depends on type and function of trim accessory
joints.
• The recommendation is for the control joints be installed over the
continuous lath, except at specified locations requiring an expansion-type
trim accessory joint.

I. Installation of expansion joints requires lath to be cut and attached to both sides of
the expansion joint flange staggered 12 inches (300 mm) o.c., attach with wire ties or
appropriate fasteners into concrete surface. (Control joints installed on top of lath.)
NOTE:
• Expansion joints are recommended where there are concrete expansion
joints (construction joints).

J. Install galvanized self-furring diamond-mesh metal lath, 2.5 or 3.4 pounds per
square yard (1.4 kg/m 2 or 1.8 kg/m 2 ) to vertical concrete surface (walls). For
horizontal concrete surfaces (ceilings), use 3.4-pound-per-square-yard (1.8 kg/m 2 )
self-furring lath.

NOTE:
• Lath shall be applied with the long dimension of sheets horizontal.
• Diamond-mesh lath is recommended rather than other styles of stucco
reinforcement lath because of the smaller size of opening in the lath
provides for easier and more positive securing of fasteners into a concrete
surface.

K. Attach lath to concrete surface with hardened concrete stub nails; low-velocity,
power-actuated pins or drill-and-drive fasteners. Fastener heads minimum of 3/8-
inch (10-mm) diameter, length of fasteners 3/4 inch (19 mm).
L. Spacing of fasteners for 2.5-pound-per-square-yard lath to walls shall be 16 inches
(400 mm) o.c. horizontally and 7 inches (180 mm) o.c. vertically. Spacing of
fasteners for 3.4-pound-per-square-inch lath to walls shall be 24 inches (600 mm)
o.c. horizontally and 6 inches (180 mm) vertically. Spacing of fasteners for lath to
ceilings shall be 16 inches (400 mm) and 7 inches (180 mm) o.c.
3.27 Stucco Assembly Attached to Concrete/Application of Stucco Basecoat
—Refer to section 3.39 in this Stucco Resource Guide.
3.28 Curing of Basecoat—Refer to section 3.40.
3.29 Stucco Finish Coat—Refer to section 3.41.
3.30 Acrylic Finish Coat—Refer to section 3.42.
3.31 Additional Types of Finishes—Refer to section 3.43.
3.32 Stucco Assembly Attached to Concrete Masonry—Refer to “Stucco Wall Assem-blies”

NOTE:
• This system is used if a greater thickness of stucco is required than is
recommended for stucco directly applied or if the concrete masonry
surface will not provide an adequate bond with the cement plaster.
• A concrete masonry wall must have been cured in accordance with
industry standards (a minimum of 30 days) before application of stucco
assembly.
• A concrete masonry surface is to be in good condition, no spalling or
delamination, and no large voids.
• Do not tool the mortar joints of the concrete masonry assembly. It is
recommended to have mortar joints struck flush with the surface.
• A concrete masonry substrate shall be aligned in accordance with its
application standards.
A. Install trim accessories—termination trim accessories (casing beads), corner
reinforcements (corner beads); trim accessory joints (control joints) and other
specified accessories in accordance with sections 3.03 and 3.04.

NOTE:
• Install per related detail sections of this Stucco Resource Guide.
• Delete trim accessories not applicable to project.
• Install per manufacturer’s recommendations.
• Depth (grounds) of trim accessory to be in accordance with the
thickness of stucco. (Refer to Plaster Thickness Tables)
• Install so as to provide the required screed and ground in accordance
with a nominal stucco thickness or 3/4 inch (19 mm) and to create a true
and level surface. (Refer to Plaster Thickness Tables)

B. Trim accessory and lath attachment

NOTE:
• The installation and pullout resistance of fasteners shall be in accor-dance
with manufacturer’s recommendations and safety requirements.
• Fasteners shall be placed in the crotch of the trim accessory flange and/
or the crotch of the lath.
• The type and condition of the concrete masonry surface affect the selection
of proper fasteners for the attachment of trim accessories and lath.
• If there is any question on the pullout strength of the fasteners, sample
testing on the wall is recommended.
• Bend lath and continue around corners, a minimum of 12 inches (300
mm), or install a corner reinforcement.
• Apply so as long dimension or lath is horizontal. Apply lath taut.
• Attachment of lath should be at furring points.
• Fasteners shall be placed in the crotch of the flanges and or the crotch
of the lath.
• Spacing of fasteners may depend on type and size of the concrete
masonry units.
• For substrates of concrete masonry units, brick or tile, it is recom-mended
that the fasteners be placed in the mortar joints. (This will
minimize damage to the individual units).
C. Indicate type of termination trim accessory (casing bead/foundation weep screed):
___________________________________________________________________
Indicate name of manufacturer (optional): _________________________________
D. Attach termination trim accessory to concrete masonry surface with hardened
concrete stub nails; low-velocity, power-actuated pins or drill-and-drive fasteners.
Fastener heads minimum of 3/8-inch (10-mm) diameter, length of fasteners 3/4 inch
(19 mm); spacing of fasteners 12 inches (300 mm) o.c.
E. Indicate the type of corner reinforcement (corner bead): ______________________
and name of manufacturer (optional): _____________________________________

NOTE:
• Corner reinforcement is recommended at vertical exterior and slanted
corners.
• Selection of proper type in accordance with specified finish coat.
• A welded wire plastic-nose or PVC corner bead is recommended if finish
coat is a sand-finish stucco or acrylic finish coat.
F. Attach corner reinforcement to concrete masonry surface with hardened concrete
stub nails; low-velocity, power-actuated pins or drill-and-drive fasteners. Fastener
heads minimum of 3/8-inch (10-mm) diameter, length of fasteners 3/4 inch (19 mm);
spacing of fasteners 12 inches (300 mm) o.c. staggered.
G. Indicate type of trim accessory joint (control joint, expansion joint, reveal or other
style): ______________________________________________________________
Indicate name of manufacturer (optional): _________________________________

NOTE:
• Control or expansion joints are recommended at locations of concrete
masonry expansion joints (construction joints).
• Trim accessory joints (control joints) are recommended, but not as
frequently as for framed construction.
• Control joints are recommended for areas greater than 200 square feet.
Maximum recommended length of a panel is 20 feet (6 m). Panel size
should not exceed a 3-to-1 ratio.
• The location of trim accessory joints and the type are by the architect.
H. Attach trim accessory joints to concrete masonry surface with hardened concrete
stub nails; low-velocity, power-actuated pins or drill-and-drive fasteners. Fastener
heads minimum of 3/8-inch (10-mm) diameter, length of fasteners 3/4 inch (19 mm);
spacing of fasteners 12 inches (300 mm) o.c. staggered.
I. Installation of expansion joints requires lath to be cut and attached to both sides of
the expansion joint 12 inches (300 mm) o.c. staggered, with appropriate fasteners,
into concrete masonry joints.
J. Installation of lath reinforcement to concrete masonry

NOTE:
• Do not begin lathing work until all unsatisfactory conditions are
resolved.
• A water-resistant barrier is not normally required or recommended for
this stucco assembly. A combination self-furring lath and water-resistant
barrier (paper-backed lath) is the style of lath recommended if the
project documents specify a water-resistant barrier over the concrete
masonry substrate.
• Lath shall be applied with the long dimension of rolls and/or sheets
horizontal.
K. Indicate type of self-furring lath: _________________________________________
Indicate name of manufacturer (optional): _________________________________
Refer to section 2.07 for lath selection.

NOTE:
• Delete lath types not applicable.
• If type of lath is not specified, it is the contractor installing the lath who
selects the type for the project. Lath selected by contractor is to be
installed only after it has been approved.
• All lath to be in accordance with this Stucco Resource Guide and its
reference standards. Refer to section 1.04.

L. Attach lath to concrete masonry surface with hardened concrete stub nails; low-velocity,
power-actuated pins or drill-and-drive fasteners. Fastener heads minimum
of 3/8-inch (10-mm) diameter, length of fasteners 3/4 inch (19 mm).
M. Spacing of fasteners for attachment of woven wire lath, welded wire lath and 2.5-
pound-per-square-yard diamond-mesh lath: 16 inches (400 mm) o.c. horizontally.
For attachment of 3.4-pound-per-square-yard diamond-mesh lath: 24 inches (600
mm) o.c. horizontally. Vertical attachment of lath shall be 7 inches (180 mm).
3.33 Stucco Assembly Attached to Concrete Masonry/Application of Stucco Basecoat
—Refer to section 3.39 in this Stucco Resource Guide.
3.34 Curing of Basecoat—Refer to section 3.40.
3.35 Stucco Finish Coat—Refer to section 3.41.
3.36 Acrylic Finish Coat—Refer to section 3.42.
3.37 Additional Types of Finishes—Refer to section 3.43.
3.38 Stucco Assembly to Sheathed Construction—Refer to “Stucco Wall Assemblies”
section details A2 and A3 in this Stucco Resource Guide.

NOTE:
• Framed construction refers to a wood framing assembly or a light-gauge
steel framing assembly with appropriate sheathing.
• It is recommended that the minimum size of wood framing member the
stucco system is going over be 2x4 and standard or better grade.
• It is recommended that the minimum size of steel framing members be 3
1/2 inches (88 mm) and a minimum of 20-gauge (.0329)
• Open-frame construction is an approved framing method for attachment
of stucco assembly, but not recommended for best performance.
• Exterior sheathing board to have firm contact with framing members (no
gaps).
• Framing assembly (substrate) to be true, straight and level. Align in
accordance with its application standards.
• It is recommended that the wood framing and wood sheathing board
have a moisture content of less than 19 percent before starting the scope
of the stucco work.
• Stucco is classified as a brittle exterior cladding, which means the
cement plaster membrane is not flexible. The substrate to which the
stucco systems is attached must be rigid and a minimum design
deflection of L/360.
• The structure of the building to which the stucco system is installed can
be load or non-load bearing walls.
• It is recommended that the shear value of the wall to be created by the
structure itself, not the stucco system.
• Appropriate exterior sheathing boards over which to install the stucco
assembly:

1. Exterior gypsum sheathing
2. Glass-mat gypsum sheathing
3. Cementitious backer board (may require paperback lath)
4. Exterior-grade plywood
5. Oriented strand board

• Exterior-grade plywood and oriented strand board shall be installed with
a minimum of 1/8 inch (3 mm) gap along all panel edges and ends.
• Exterior sheathing boards to be installed per the manufacturer’s
recommendations and building code requirements.
• Exterior sheathing board, once installed, requires protection from
climatic conditions, until the installation of the stucco system.
• Do not begin stucco system work until all unsatisfactory conditions are
resolved.
• Sections of flashing or trim accessories that butt each other (at corners
or another condition) need to be lapped, caulked, or have a strip of self-adhering
membrane over the joints. This is to prevent moisture from
getting to the building structure.

A. The stucco contractor is to install stucco system component flashing (window head
flashing, expansion joint/weep flashing) only if this scope of work is indicated in the
project construction documents and stated in the stucco contractors performance
contract.

NOTE:
• Stucco system component flashing does not refer to standard roof or
other types of building flashing.
• Refer to the section details and “Scope of Work Responsibilities” section
of this Stucco Resource Guide.
• Delete if not applicable to project.

B. Install a water-resistant barrier “WRB” as part of the stucco assemby. Water-resistant
barrier, per F.S. UU-B-790A grade D 60-minute; spunbounded olefin housewrap for
a stucco system, or an approved weather-resistant barrier designed for a stucco
system.

NOTE:
• It is required to use water-resistant barriers with all wood or steel framed
structures.
• This guide requires two layers of Grade D 60-minute building paper or
two layers of olefin housewrap over the wood sheathing. A combination
of these two water-resistant barriers can be used. The first layer is to be
the housewrap water-resistant barrier.
• It is recommended that two layers of water-resistant barrier be installed
over all types of sheathing boards.
• All flashing and water-resistant barrier to be installed in such a manner
so as to prevent moisture from entering at all edges (tops and sides).
• Do not damage, in any way, the water-resistant barrier during installa-tion.
If damage occurs, repair before starting the trim and lathing work
and/or completely replace the water-resistant barrier.
• The water-resistant barrier is to be installed “shingle-fashion” so that
natural direction of water flow would be over and onto the next sheet.
• Install long dimension horizontal to framing.
• Water-resistant barrier shall have horizontal laps of 2 inches (50 mm)
minimum. Vertical laps shall be 6 inches (150 mm) minimum.

C. Attach water-resistant barrier to sheathing with small staples so as it is taut and flat.
Refer to details in the “Window Flashing Applications” section of this Stucco
Resource Guide.

D. Install stucco system trim accessories—foundation weep screed, casing beads,
corner reinforcements (corner beads), trim accessory joints (control joints, expansion
joints, reveals) and other specified accessories in accordance with sections 3.03 and
3.04.

NOTE:
• Install per related detail sections of this Stucco Resource Guide.
• Delete trim accessories not applicable to project.
• Install per manufacturer’s recommendations.
• The depth (grounds) of trim accessory to be in accordance with the
thickness of stucco. (Refer to Plaster Thickness Tables)
• Install so as to provide the required screed and ground in accordance
with nominal stucco thickness requirements. (Refer to Plaster
Thickness section.)
• Install so as to produce a true and level surface for the cement plaster.

E. Trim accessory and lath attachment

NOTE:
• The type and condition of the sheathing board and framing members
affect the selection of proper fasteners for the attachment of trim
accessories and lath.
• The installation and pullout resistance of fasteners shall be in accor-dance
with manufacturer’s recommendations and safety requirements.
• Fasteners shall be placed in the crotch of the trim accessory flange and/
or the crotch of the lath.
• If there is any question on the pullout strength of the fasteners, sample
testing on the wall is recommended.
• The same fasteners can be used as a combination attachment for trim
accessories and lath (and in some construction, the sheathing board).
• Lath shall be applied with long dimension of the sheets or rolls
horizontal (perpendicular) to framing members. Apply lath taut.
• Bend lath and continue around corners to next framing member and/or
corner reinforcement.
• Attachment of lath should be at furring points.
• Thickness of sheathing board or boards dictates the length of fasteners.
• Fasteners to penetrate into wood or steel framing members. Attachment
into only the sheathing board is not recommended.
• Fasteners to penetrate a minimum of 3/4 inch (19 mm) into wood
framing members.
• The thickness of sheathing boards of plywood and oriented strand board
does not make up part of the minimum 3/4-inch (19-mm) fastener
penetration requirement.
• Fasteners to be centered on flange (ends) or framing member. A
minimum of 3/8 inch (10 mm) from edge. Both legs of staple to penetrate
framing member.
• Fasteners to penetrate a minimum of 2 full threads past the steel framing
member flange.
• All types of fasteners shall bear tight against attachment item.
• Construction methods and design (layout) may dictate that some
fasteners only penetrate into sheathing board in order to attach trim
accessory.
• Sheathed framed construction with vertical trim accessory joints that
require the lath to be terminated (cut) and installed on top of the flanges
shall be placed at framing member locations. Lath shall be attached with
appropriate fasteners through the trim accessory flange, sheathing and into
the framing member. The lath/flange on each side of the trim accessory
joint is recommended to be attached to a framing member. Double framing
supports may be required at these locations. This condition does not
pertain to control joints installed over continuous lath.

F. Indicate type of termination-at-foundation trim accessory (foundation weep screed,
as required by Building Code):___________________________________________
Indicate name of manufacturer (optional): _________________________________

NOTE:
• Refer to “Termination at Foundation” detail section of this Stucco
Resource Guide.
• Foundation weep screeds and in some design details casing beads can
serve as a termination for the stucco at the building foundation area.
• Building codes require a foundation weep screed.
• Finished edge of stucco surface to be no lower than 4 inches (100 mm)
from finished grade or 2 inches above a hard surface.

G. Fasteners for attachment of trim accessories, foundation trim and lath

NOTE:
• Refer to section 3.38-E.
• Length of fasteners depends on thickness of sheathing boards.
• Stucco contractor has the option of selecting appropriate fasteners from
list below.
Wood-sheathed framing:

1. Roofing nails: 11-gauge • 7/16-diameter head • 1 1/2 inches long (i.e., 1/2 inch
wood sheathing)
2. Staples: 16-gauge • 3/4-inch crown • 1 3/8 long (i.e., 1/2 inch wood sheathing)
3. Type W screws: wafer head • 1 1/2 inches long (i.e., 1/2 inch wood sheathing)
Sheathed steel framing:
1. Type S screws: wafer head • self-drilling • 1 inch (25 mm) long (i.e., 1/2 inch
sheating)

H. Indicate type of foundation trim accessory (foundation weep screed or casing bead):
___________________________________________________________________
Indicate name of manufacturer (optional): _________________________________
I. Attach foundation trim accessory to building structure, with appropriate fastener
selected from list in section 3.38-G. Spacing of fasteners 12 inches (300 mm) o.c.

NOTE:
• Refer to the “Termination at Foundation” detail section of this Stucco
Resource Guide.

J. Indicate type of termination trim accessory (casing bead):_____________________
Indicate name of manufacturer (optional): _________________________________
K. Attach termination trim accessory to building structure, with appropriate fastener
selected from list in section 3.38-G. Spacing of fasteners 12 inches (300 mm) o.c.

NOTE:
• Refer to detail sections of this Stucco Resource Guide.
L. Indicate type of corner reinforcement (corner bead): _________________________
Indicate name of manufacturer (optional): _________________________________

NOTE:
• Refer to the “Corners” detail section of this Stucco Resource Guide.

N. Indicate the type of trim accessory joint (control joint, expansion joint, reveal or
other style): _________________________________________________________
Indicate name of manufacturer (optional): _________________________________
O. Attach trim accessory joints to building structure, with appropriate fastener selected
from list in section 3.38-G. Spacing of fasteners 12 inches (300 mm) o.c. staggered.

NOTE:
• Refer to “Trim Accessory Joints” detail section of this Stucco Resource
Guide.
• Joints are recommended if the area is 150 to 180 square feet (14 to 17
m 2 ). Maximum recommended length of a panel is 18 feet (6 m). Panel
size should not exceed a 3-to-1 ratio.
• The location of trim accessory joints and the type are by the architect.
• The design layout of the trim accessory joints and the location of framing
members may require the control joints to be attached to the sheathing
and/or attached with tie wire to the lath.
• The application of sealants is recommended in conjunction with the
installation of trim accessory joints. Refer to section 3.04 and details in
the “Trim Accessory Joints” section of this Stucco Resource Guide.
• A continuous (unbroken) water-resistant barrier is required behind all
trim accessory joints.
• Control joints are the type of trim accessory joints recommended for
installation over continuous (unbroken) lath. Expansion joints and
reveals are types of trim accessory joints which require the lath to be
broken behind the joint.
• If attachment of control joint is to lath or other trim accessories, use 18-
gauge wire tie 12 inches (300 mm) o.c. to each flange, staggered.
• Aluminum and/or PVC reveals require that when the lath is installed
over the flange, it totally covers it. The welded wire and woven wire lath
shall be installed so as the crotch of the lath is over the flange.
P. Installation of expansion joints and reveals requires lath to be cut and attached to
both sides of the joint flange.
Q. Indicate type of self-furring lath: _________________________________________
Indicate name of manufacturer (optional):__________________________________
(Refer to section 2.07 for lath selection.)

NOTE:
• If type of lath is not specified, the contractor installing the lath selects
the type for the project. Lath selected by contractor is to be installed
only after it has been approved.
• Over sheathing board, lath must be self-furring type and or use furring
fasteners.
• It is recommended that paperback lath not be used on framed sheathed
construction. Installing the water-resistant barrier separate from the
lath installation provides a better flashing method and a uniform
thickness of the stucco. On vertical open-frame construction, paperback
lath or line wire and paper are required.

R. Attach lath to building structure, with appropriate fastener selected from list in
section 3.38-G.

NOTE:
• Refer to detail section of this Stucco Resource Guide.
• Install lath with long dimension of sheets/rolls horizontal, perpendicular
to framing members.
• Install so overlapping areas are uniform and per manufacturer’s
recommendations and building code requirements.
• Install so as lath is level, flat and taut.
• Bend lath and continue around corners to next framing member or
install corner beads..

S. For attachment of 2.5-pound-per-square-yard diamond-mesh lath, the spacing of
framing “studs” shall be 16 inches (400 mm) o.c. For attachment of woven wire
lath, welded wire lath and 3.4-pound-per-square-yard diamond-mesh lath, the
spacing of framing “studs” shall be 24 inches (600 mm) o.c. Vertical fasteners for
attachment of all lath to studs shall be 6 inches (150 mm) o.c. (fasteners to pentrate
into framing supports studs).

NOTE:
• Refer to section 3.36 on trim accessory and lath attachment.
• All spacing is maximum.

3.39 Application of Stucco Basecoat

NOTE:
• Verify that trim accessories and lath are properly secured.
• Verify trim accessories and lath are installed so as to provide proper
screeds, thickness and alignment for the plastering operation.
• Do not begin plastering work until unsatisfactory conditions are
resolved.
• Cement plaster can be applied by trowel or machine.
• Apply basecoat to entire wall panel and/or section without interruption
or “cold joints.”
• Install stucco basecoat in accordance with the requirements and
references in this Guide Specification and the project construction
documents.

A. Indicate the permissible mix number and its proportions to be used for the basecoat:
___________________________________________________________________
Refer to Section 2.15.

NOTE:
• Delete basecoat mixes not applicable to this project.
• Do not change selected mix or proportions after plastering operation has
started.
• Measurement of ingredients (materials of the mix) to be done with
devices of known volume, accurate, and successive batches proportion-ally
alike.
• Use only enough mix water to make plaster a workable consistency.
• Admixtures are for improving the basecoat mix or enhancing the plaster
application. Use products manufactured strictly for this purpose and in
accordance with manufacturer’s recommendations.
B. Apply stucco first (“scratch”) coat in a nominal thickness of 3/8 inch (10 mm).
Refer to Plaster Thickness Tables in this Stucco Resource Guide. First coat to
completely embed the lath. First coat to be thick enough to go beyond lath so as to
allow for scoring of cement plaster surface.

NOTE:
• Scoring of the first coat should be uniform and shallow, 1/8 inch (3 mm).
C. Apply stucco second (“brown”) coat in a nominal thickness of 3/8 inch (10 mm)
over stucco first coat. Second coat thickness to bring the combined basecoats (first
and second) thickness to a nominal thickness of 3/4 inch (19 mm). (Refer to Plaster
Thickness Tables).

D. Apply the second coat with sufficient material and pressure to ensure a tight uniform
bond to the first coat.
E. The “double-back” method of applying successive coats is recommended. This
procedure has little or no delay between applying the second coat over the first coat.

NOTE:
• Advantages of this method are that it creates a better bond between the
two coats, it provides for uniform and better curing of the basecoat and it
reduces delay on the project.
• Apply second coat as soon as the first coat is rigid enough to receive it.
• This method is not recommended for open-frame construction (vertical
and horizontal surfaces).

F. Rod the second coat to a true, even plane, filling surface defects with cement plaster.
G. Trowel-float the second coat surface uniformly.

3.40 Curing of Basecoat

A. Climatic conditions dictate the need for moist-curing.

NOTE:
• Cement plaster gains its strength in the first day or two.
• Moist-curing enables the cement materials to hydrate properly and the
stucco membrane to reach its desired physical properties.
• Moist-curing helps prevent “craze cracking.”
• Cement plaster basecoat to cure for a minimum of seven days before
starting finish coat application. Moist cure for the first two days.

B. Moist-curing is recommended when the ambient temperature is 77....F (25....C) or
higher and/or when the ambient relative humidity is below 70 percent and the
conditions are windy.

NOTE:
• Moist-cure in the morning and/late afternoon for a period of two days.
• Moist-cure with a fine mist of clean water; do not saturate.
• Moist-cure only after the basecoat has set and is hard.
• Extreme weather conditions may require plastic sheets to retard
evaporation.

C. The stucco basecoat should be protected from freezing for a period of 24 hours after
application.
NOTE:
• Do not moist-cure if basecoat is subject to freezing.
• Do not use frozen materials in mix.
• Do not apply cement plaster to a surface that is frozen or contains frost.

3.41 Stucco Finish Coat

NOTE:
• “Stucco finish coat” in this specification refers to the cement plaster
finish of which there are two types: (1) Job-site stucco finish coat, and (2)
manufactured stucco finish coat.
• For colored (integral color) stucco finish coat, the use of a manufactured
stucco finish is recommended.
• It is recommended that the lighter tones of color (pastel colors) be used
for mineral stucco finishes.
• Stucco finish coat color uniformity cannot be guaranteed because of a
variety of uncontrollable factors (suction of basecoat and the application
of the finish coat will vary with climatic conditions). Manufactured
stucco finish coat will produce the most consistent color.
• Time necessary between the completion of basecoat (brown coat) and the
application of finish coat will vary with climatic conditions.
• It is recommended that the basecoat which is to receive the finish coat
cure for a minimum of seven days. (This does not pertain to section 3.14
“Finish Coat Direct to Concrete”)
• For job-site finish coat, it is recommended that the coloring agents be
from a stucco finish-coat manufacturer.
A. Stucco basecoat (or concrete surface) is required to be in a proper condition before
application of stucco finish coat or acrylic finish coat.

NOTE:
• Do not apply finish coat until all irregularities in the basecoat have been
addressed.

B. Apply stucco finish coat to damp cement plaster basecoat.

NOTE:
• Dampen the basecoat with a mist of clean water to obtain uniform
suction. Do not saturate: there should not be any visible water on the
surface when the finish coat is applied.

C. Apply stucco finish coat in a nominal thickness of 1/8 inch (3 mm). (Refer to Stucco
Thickness Tables).
D. Apply stucco finish with sufficient material and pressure to ensure a tight bond with
basecoat (brown coat) or concrete surface.
E. Apply stucco finish to a uniform thickness and in a consistent finish in accordance
with style of finish specified.

NOTE:
• Apply finish coat starting from the top of the wall surface and work
down.
• Apply finish coat with no interruptions; no cold joints.
• Apply finish coat so there are no “scaffold” lines or joint stains.

F. Moist-curing of finish coat is not recommended, except in severe climatic conditions
(e.g., extreme heat, strong winds and low relative humidity).

NOTE:
• Moist-curing of the stucco finish coat can cause discoloration.
G. Indicate the type of stucco finish coat:
Job-site mixed stucco finish __________________________________________
Manufactured stucco finish __________________________________________

NOTE:
• Delete the type of finish not applicable
H. Indicate the style of stucco finish _________________________________________
(Refer to 3.41-I)

NOTE:
• Smooth trowel finish is not recommended when the material is cement
plaster.
• Very heavy textures may have to be applied in the basecoat because a
nominal stucco finish coat is not thick enough.
• It is recommended that a sample of the finish coat be applied to a wall at
the project site if possible.
• Provide style and color sample of stucco finish coat for approval before
starting the application of finish coat. Delete if not applicable.
• The approved sample to be maintained on project site until the scope of
stucco work is completed and approved.
• Use only enough water in stucco finish coat mix to make it workable.

I. Styles of stucco finish

1. Sand Float Finish (fine, medium or course)
2. Machine Dash Finish (light/medium/heavy)
3. Knockdown Dash Finish
4. Lace Finish
5. Light Comb Finish
6. English Finish
7. Frieze Finish
8. Spanish Finish.

NOTE:
• Delete finish styles not applicable.

J. Indicate the color of stucco finish ________________________________________

3.42 Acrylic Finish Coat

NOTE:
• The acrylic finish to be 100-percent acrylic polymer base.
• Acrylic finish coat and manufacturer to be recommended by NWCB and/
or regional Wall and Ceiling Association.
• Basecoat of cement plaster that is to receive an acrylic finish coat shall
have been floated and/or have a stucco sand-finish.
• Do not apply finish until all irregularities in the basecoat or concrete
surface have been addressed.
A. Indicate style of acrylic finish: __________________________________________
Indicate color of acrylic finish: __________________________________________
Indicate approved manufacturers: ________________________________________

NOTE:
• Refer to manufacturer for different styles and color selection.

B. Apply acrylic finish over stucco basecoat (brown coat) or concrete surface a
minimum of 1/16 inch (2 mm) dry thickness.

NOTE:
• Acrylic finish to be applied per the manufacturer’s recommendations.
• Stucco basecoat shall be free of efflorescence. Apply acrylic finish coat
only at an ambient temperature of 40 °F (4 °C) and rising. This
temperature is recommended for a minimum of 24 hours after applica-tion.
• Acrylic finish shall maintain a wet edge at all times. The finished
surface shall have no scaffold or stain lines.
• Protect finished surface from climatic conditions until dry.
• It can be difficult to achieve a uniform color using a spray-applied acrylic
finish. Therefore, it is recommended that a troweled application of the
acrylic finish be applied first.
• Do not moist-cure acrylic finish.

C. Apply acrylic finish coat with sufficient material to uniformly and completely cover
the basecoat.

3.43 Additional Types of Finishes

NOTE:
• To be approved by NWCB.

A. Factory-mixed 100-percent acrylic-based elastomeric finish
B. High-quality exterior acrylic paint.Portland Cement

NOTE:
• Applied per manufacturer’s recommendations over a stucco finish or
acrylic finish.

C. High-quality exterior elastomeric paint

NOTE:
• Applied over a stucco finish coat or acrylic finish coat.