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Historic Preservation - Technical Procedures

Spectitle:

Painting Exterior Stucco

Procedure code:

0991006R

Source:

Hspg Prepared For Nps - Sero

Division:

Finishes

Section:

Exterior Painting

Last Modified:

02/24/2012

Details:

Painting Exterior Stucco



PAINTING EXTERIOR STUCCO


PART 1---GENERAL

1.01 SUMMARY

    A.   This procedure includes guidance on painting exterior
         stucco surfaces.

    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

         3.   Submittals

         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
         fire.

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
              application.

         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
              degrees F.

         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.


PART 2---PRODUCTS

2.01 MANUFACTURERS

    A.   The Sherwin Williams Co.
         101 Prospect Ave. N.W.
         Cleveland, OH  44101
         216/566-2000

    B.   Benjamin Moore
         51 Chestnut Ridge Road
         Montvale, NJ 07645
         201/573-9600

2.02 MATERIALS

    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
              based paints.

    C.   Mineral Spirits (as recommended by paint manufacturer to
         thin conditioner):

         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*;
              Solvent naphtha*.

         3.   Potential Hazards:  TOXIC AND FLAMMABLE.

         4.   Safety Precautions:

              a.   AVOID REPEATED OR PROLONGED SKIN CONTACT.

              b.   ALWAYS wear rubber gloves when handling
                   mineral spirits.

              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.

2.03 EQUIPMENT

    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
         PAINT.

    B.   Garden hose or low pressure water spray equipment

    C.   Paint rollers

    D.   Paint spray


PART 3---EXECUTION

3.01 PREPARATION

    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
                   AMMONIA.

              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
              instructions:

              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
                   PENETRATION.  

              b.   Allow to dry as per manufacturer's
                   instructions.

         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
         applying paint.  

         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
              METHODS.

         2.   Allow adequate drying times between each coat of
              paint.

         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