Sealed Stucco System

The sealed stucco system was developed to provide a serviceable stucco system for both residential and light commercial construction applications. The sealed stucco system is designed for Climate Zones 1, 2, and 3, as defined by the International Energy Conservation Code with special emphasis on Zones 1, and 2. These zones are particularly susceptible to high-wind storm events (tropical storms, hurricanes, or other weather extremes) and a high airborne salt concentration.

For over 40 years residential stucco systems in the Florida region were not being installed as a code-required wall-covering system. They were not being installed to provide structural shear values or fire resistance values. Local stucco contractors and experts recognized that international standards and the codes referencing international standards need regional modification for some (or many) of their “boilerplate” international requirements.

Differences in regional climate, regional construction methodologies, and regional building envelope needs ultimately required the locally-trained construction specifier to modify or eliminate some of these international provisions for better service performance of the product.

Stucco standards allow the stucco finish to be installed over “open framing” without any painting. As a result the stucco can be applied with white or gray material, but also tinted with a cement dye to offer a complete range of possible color hues and tints for the consumer. Installing stucco in this manner provides the additional marketing benefit of a “maintenance-free” exterior.

In such instance a standard might require a “drain plane” behind the stucco to protect the underlying wood sub-framing members. This “drain plane” can manage minor amounts of water that would, or could, migrate through the stucco and the underlying metal lath by way of normal and anticipated cracking of the stucco plane. The water eventually migrates back out to the surface of the stucco at the “weep screed” placed at the foundation wall.

In Florida applications, local experts have long recognized that this process cannot be applied in our salt rich environment. Migrating water carries migrating salts and the migrating salts create rusting of the metal lath behind the stucco plane. Therefore water that might be harmless in a different environment is not harmless in Florida’s environment.

Accordingly, stucco systems in Florida need a “face barrier system” which includes proper sealants of all penetrations. The goal has always been to absolutely bar and prevent the passage of any water through the stucco system or around stucco penetrations. With such system in place there is no need for a “drain plane” system since any water that might reach it for its intended purpose will lead to the demise of the system itself.

Air barriers are required and can be sequenced so as to serve as both an air barrier and a secondary water barrier depending upon their type, application, and integrated construction detailing. In the 1980’s control homes built in Southeast Florida were constructed using an air barrier and water barrier placed directly underneath the wire lath and stucco. Final testing results yielded excellent performance as an air barrier and stucco substrate.

As time went along, new inventions such as plastic corner beads and accessories evolved creating some of their own unique problems. Traditional techniques of “rodding” the corners seemed to vanish. Precast accent trim (which was previously attached after the stucco and waterproofing) started to be applied in a faux fashion by using newly developed plastic casing beads “back-to-back” to create leak paths directly to the metal underlayment and wood sub-framing. The placement of foam bands in similar situations followed suit and yielded the same complications.

Fenestration changed. Screens that were inside, moved outside. Mechanical joints became stressed by improper installation. Unintended hydraulic heads were caused by screen blockage. Reduction of overhangs and wall stresses also acted on the mechanical joints, creating pathways for water intrusion.

Traditionally rolled applications of coatings providing the required millimeter thickness were replaced with airless sprayers and extension wands. These have allowed the exterior coating to appear properly painted but, when millimeter thickness is measured, the covering is only 10% of the code-required thickness. This, of course, does not bridge the underlying cracking of the stucco, nor does it provide the required waterproofing capabilities necessary for a face barrier system.

Quality sealants and tool joint preparation also fell by the wayside. It was replaced by inexpensive caulks and improperly prepared bases. Provided that an initial house was properly repainted to the correct mil thickness after the recommended five years, the stucco system suffered little or no harm. However, after the fifth year problems manifested themselves exponentially in relation to time. Simple stucco repairs became much more cost- and labor-intensive.

The required maintenance and re-coating after five years was usually only casually advised to the consumer and was not given the proper gravity. Many homeowners were not told that if they did not re-coat after five years, their building could suffer more severe damage and costly repairs than would have otherwise been incurred. Not surprisingly, these problems led to an abundance of stucco problems, finger-pointing, and litigation.

The sealed stucco system is a technique to applying stucco that entirely avoids the aforementioned stucco problems. It has over 40 years of time-honored, complication-free service life. It was developed to fulfill the specific requirements that are necessary for a successful stucco installation in Florida or similar environment.

The details and protocols contained in its installation instructions restore the time-old traditions of quality installation. They require the elimination of plastic-type corner beads with inhibitive phalange embedment properties. They require the stucco contractor to provide the waterproofing contractor the grooves and reliefs necessary to obtain a subsequent seal with a quality sealant. They require the coding to be installed to the proper thickness using proper methodology. They require the sealant type and grade. But most importantly, they require the work be done by way of someone trained to either install or supervise the installation of the system to ensure uncompromising quality and performance.

Please follow the links for the system installation requirements and certified installer requirements.