Historic Preservation - Technical Procedures
Painting Exterior Stucco
Hspg Prepared For Nps - Sero
Painting Exterior Stucco
PAINTING EXTERIOR STUCCO
A. This procedure includes guidance on painting exterior
B. Unlike wood and metal, painting a stucco surface does not
afford any extra protection.
C. Early stucco was generally left unpainted. The natural
colors of the sands and aggregates used in the stucco
mixture provided the color. However, repairs may require
the stucco to be painted when a perfect color match
between the original material and the patches cannot
otherwise be achieved.
D. See 01100-07-S for general project guidelines to be
reviewed along with this procedure. These guidelines
cover the following sections:
1. Safety Precautions
2. Historic Structures Precautions
4. Quality Assurance
5. Delivery, Storage and Handling
6. Project/Site Conditions
7. Sequencing and Scheduling
8. General Protection (Surface and Surrounding)
These guidelines should be reviewed prior to performing
this procedure and should be followed, when applicable,
along with recommendations from the Regional Historic
Preservation Officer (RHPO).
1.02 SYSTEM DESCRIPTION
A. Paint manufacturers have developed paint systems which
are made to work together. These systems include primers
and appropriate, compatible top coats which can vary
depending on the substrate and can vary between
manufacturers. As a result appropriate primers and
compatible top coats, both from the same manufacturer
should be used. A paint film is in good condition when
it is clean and free of any peeling or cracking. It is
not chalking, and it retains its color and gloss.
1.03 DELIVERY, STORAGE AND HANDLING
A. Packing and Shipping: Paints shall be in sealed
containers that legibly show the designated name, formula
or specification number, batch number, color, quantity,
date of manufacture, manufacturer's formulation number,
manufacturer's directions including any warnings and
special precautions and name of manufacturer. Pigmented
paints shall be furnished in containers not larger than
five gallons. Paints shall be stored on the project site
and shall be stored to prevent freezing. All paints
shall be kept covered and safeguards taken to prevent
1.04 PROJECT/SITE CONDITIONS
A. Environmental Requirements:
1. Unless otherwise recommended by the paint
manufacturer, the ambient temperature shall be at
least 50 degrees F. Consult manufacturer for upper
temperature limits. Do not apply latex based
paints when the temperature is expected to fall
below 50 degrees F during the first 24 hours after
2. Do not apply paint when the relative humidity
exceeds 85%. Drying times are also affected by
relative humidity. Those stated by manufacturers
generally are based on 50% RH and approximately 77
3. Do not apply any of the coats of paint in the
direct sun. It shall be applied only when the
surface to be painted is in the shade and the sun
is shining on the opposite elevation. The west
elevation should be painted in the morning when the
sun is shining on the east elevation; the north
elevation should be painted around noon when the
sun is shining on the south elevation; the east
elevation should be painted in the afternoon when
the sun is shining on the west elevation; and the
south elevation should be painted late in the
afternoon when it is in full shade.
4. Do not apply paint to damp surfaces, in misty or
rainy weather, in the snow or where there is
visible ice or frost on the surfaces.
A. The Sherwin Williams Co.
101 Prospect Ave. N.W.
Cleveland, OH 44101
B. Benjamin Moore
51 Chestnut Ridge Road
Montvale, NJ 07645
NOTE: Chemical products are sometimes sold under a common
name. This usually means that the substance is not as pure as
the same chemical sold under its chemical name. The grade of
purity of common name substances, however, is usually adequate
for stain removal work, and these products should be purchased
when available, as they tend to be less expensive. Common
names are indicated below by an asterisk (*).
A. Acrylic Latex Paint such as those from Sherwin Williams,
Benjamin Moore or approved equal.
1. All paint used shall be from the same manufacturer
and shall be appropriate for the conditions
encountered on the job site.
2. Acrylic latex paints are recommended over vinyl
acetate latex paints because the acrylics are more
alkali resistant, important when painting stucco
(or brick). They are more flexible and "breathe"
more than the oils do. Many are also self-priming
so the same paint can be used for both the prime
coat and top coat. Latex paint can also be applied
to slightly damp surfaces, though they must be
absolutely clean and free of any chalking paint.
3. Oil/alkyd based paints may also be used as
described in Part 3 Execution.
B. Masonry conditioner/sealer if recommended by paint
manufacturer and RHPO.
CAUTION: SEALER MAY TRAP MOISTURE WITHIN THE STUCCO,
CAUSING SPALLING OR PAINT/SEALER FAILURE.
1. The sealer will prevent old stucco from absorbing
the water from the latex top coat which would
prevent the paint from adhering properly.
2. Conditioners/sealers are also alkali-resistant and
will prevent adverse chemical reactions from
occurring between the stucco and oils in oil/alkyd
C. Mineral Spirits (as recommended by paint manufacturer to
1. A petroleum distillate that is used especially as a
paint or varnish thinner.
2. Other chemical or common names include Benzine*
(not Benzene); Naphtha*; Petroleum spirits*;
3. Potential Hazards: TOXIC AND FLAMMABLE.
4. Safety Precautions:
a. AVOID REPEATED OR PROLONGED SKIN CONTACT.
b. ALWAYS wear rubber gloves when handling
c. If any chemical is splashed onto the skin,
wash immediately with soap and water.
5. Available from construction specialties
distributor, hardware store, paint store, or
printer's supply distributor.
A. Brushes: Use nylon bristle brushes for water-based
paints; use natural bristle brushes (pre-conditioned by
soaking in linseed oil for 24 hours) for oil-based
paints. DO NOT USE THE SAME BRUSH FOR BOTH TYPES OF
B. Garden hose or low pressure water spray equipment
C. Paint rollers
D. Paint spray
A. Surface Preparation:
1. Make sure all stucco repairs have been made and the
surfaces to be painted are sound and dry.
2. Using scrapers and stiff bristle brushes, remove
any loose, flaking paint.
3. To remove any old chalking paint:
a. Wash surfaces with a non-ionic detergent using
low pressure water (80-100 psi) or a garden
hose. If mildew is a problem, add bleach to
the detergent. For guidance on cleaning
exterior masonry and stucco, see 04200-02-R.
NOTE: DO NOT USE DETERGENT CONTAINING
b. Thoroughly rinse the surface with clean, clear
water and allow to dry.
4. If recommended by the paint manufacturer, apply a
masonry conditioner/sealer which has been thinned
if necessary according to manufacturer's
a. Apply using brush, roller, or spray, only as
much as surface will absorb.
NOTE: DO NOT ALLOW A VISIBLE GLAZE TO APPEAR
ON THE SURFACE OF THE STUCCO. DO NOT APPLY TO
A DAMP SURFACE AS THIS WILL PREVENT PROPER
b. Allow to dry as per manufacturer's
5. Scrape or brush off all loose paint. Spot prime
before reapplying paint.
3.02 ERECTION, INSTALLATION, APPLICATION
A. Follow manufacturers instructions when selecting and
1. Brush apply 2 coats of paint to insure complete
coverage. Spray equipment may also be used.
NOTE: SOME PAINT MANUFACTURERS DO NOT RECOMMEND
ROLLER APPLICATION SO CHECK FOR PROPER APPLICATION
2. Allow adequate drying times between each coat of
NOTE: FOR OPTIMAL RESULTS WHEN USING ACRYLIC LATEX
PAINTS, MAINTAIN A TEMPERATURE OF 50OF. FOR AT LEAST THE
FIRST 24 HOURS AFTER APPLICATION.
B. If using oil/alkyd paint, unless a masonry
conditioner/sealer has been used, any new patches must be
allowed to cure for at least a year before painting.
Apply two top coats, using a brush for complete coverage.
END OF SECTION