SA-DS2015-084

DEC REQUEST DS-2015-084 STAFF ANALYSIS

ISSUE: DS2015-084. Petitioner, John Farinelli on behalf of Puzzitiello Builders, LLC. seeks a Declaratory Statement concerning section R703.6.4 Application, R703.6.5 Curing, and ASTM C 926, Standard Specification for Application of Portland Cement-Based Plaster, as referenced in Chapter 46 of the 5th Edition (2014) Florida Building Code, Residential.

Petitioner seeks clarification of the following question:
Question #1: When stucco applications are installed per ASTM C 926 as permitted under the
Exception to Section R703.6.4, is compliance with Section 703.6.5 also required?

Background

Situation:

Puzzitiello Builders, LLC is a general contractor serving Palm Beach and Broward Counties. The company specializes in custom home building. The company is currently in the design stages of several residential projects. Building designs comprise both masonry and wood frame construction. Portland cement plaster (stucco) is intended as the exterior finish. As such, Sections R703.6.4 and R703.6.5 of the 5th Edition (2014) Florida Building Code, Residential Volume are of concern to the petitioner.

5th Edition (2014) Florida Building Code, Residential

R703.6.4 Application. Each coat shall be kept in a moist condition for at least 48 hours prior to application of the next coat.

Exception: Applications installed in accordance with ASTM C 926.

R703.6.5 Curing. The finish coat for two-coat cement plaster shall not be applied sooner than seven days after application of the first coat. For three-coat cement plaster, the second coat shall not be applied sooner than 48 hours after application of the first coat. The finish coat for three coat cement plaster shall not be applied sooner than seven days after application of the second coat.

5th Edition (2014) Florida Building Code, Building

TABLE 2512.6
CEMENT PLASTERS

a. The first two coats shall be as required for the first coats of exterior
plaster, except that the moist-curing time period between the first and second coats shall not be less than 24 hours. Moist curing shall not be required where job and weather conditions are favorable to the retention of moisture in the cement plaster for the required time period.
b. Twenty-four-hour minimum interval between coats of interior cement plaster. For alternative method of application, see Section 2512.8.
c. Finish coat plaster is permitted to be applied to interior cement plaster base coats after a 48-hour period.

2512.8 Alternate method of application. The second coat is permitted to be applied as soon as the first coat has attained sufficiently rigidity to receive the second coat.

2512.2 Curing. Curing of the first coat is permitted to be omitted and the second coat shall
be cured as set forth in ASTM C 926 and Table 2512.6.

2512.9. Finish Coats. Cement plaster finish coats shall be applied over base coats that
have been in place for the time periods set forth in ASTM C 926. The third or finish coat
shall be applied with sufficient material and pressure to bond and to cover the brown coat
and shall be of sufficient thickness to conceal the brown coat.

ASTM C 926

8.2 Sufficient time between coats shall be allowed to permit each coat to cure or develop
enough rigidity to resist cracking or other physical damage when the next coat is applied.
{SeeX1.4.2)

X1.4.2 Time Between Coats and Curing for Portland Cement-Based Plaster:
X1.4.2.1 The timing between coats will vary with climatic conditions and types of plaster base. Temperature and relative humidity extend or reduce the time between consecutive operations. Cold or wet weather lengthens and hot or dry weather shortens the time period. Moderate changes in temperature and relative humidity can be overcome by providing additional heating materials during cold weather and by reducing the absorption of the base by pre-wetting during hot or dry weather.

X1.4.2.2 In order to provide more intimate contact and bond between coats and to reduce
rapid water loss, the second coat should be applied as soon as the first coat is sufficiently
rigid to resist cracking, the pressures of the second coat application, and the leveling process. (Emphasis Added)

X1.4.2.3 The amount of water and the timing for curing portland cement plaster will vary
with the climatic conditions, the type of base, and use or nonuse of water-retentive
admixtures. (Emphasis Added)

Analysis:

Question #1: When stucco applications are installed per ASTM C 926 as permitted under the
Exception to Section R703.6.4, is compliance with Section 703.6.5 also required?

Petitioner Proposed Answer: The petitioner believes the answer to Question #1 is "NO". When considering the intent of the code, the petitioner can only conclude that the exception allowing compliance strictly with ASTM C 926 as contained in Section R703.6.4 Application would not require compliance with Section R703.6.5 Curing.

In support of this conclusion, the petitioner offers the following rationale:

1} As ASTM C 926 is referenced in its entirety in Section R703.6.4 Application, it stands to
reason that applications are intended to be installed as a complete system in compliance
with the entire referenced standard. Therefore, applications installed per the provisions
of the standard would not require compliance with Section R703.6.5, Curing;

2} The requirements for stucco application as contained in Section 2512 of the 5th Edition
Florida Building Code, Building Volume, defer to applications installed per ASTM C 926, as
follows:

2512.6 Curing and interval. First and second coats of cement plaster shall be applied and

moist cured as set forth in ASTM C 926 and Table 2512.6

Although the Table requires a minimum moist curing time of 48 hours and a minimum interval
between coats of 48 hours, Table Footnote b provides for an alternate method of application
under Section 2512.8, as follows:

2512.8 Alternate method of application. The second coat is permitted to be applied as soon as the first coat has attained sufficiently rigidity to receive the second coat.

2512.2 Curing. Curing of the first coat is permitted to be omitted and the second coat shall
be cured as set forth in ASTM C 926 and Table 2512.6.

3} Portland Cement Plastering (Stucco) product manufacturers reference ASTM C 926 for application of materials, as stated in ICC-ES Report ESR-2535, a copy of which is attached for review.