What is Stucco?

Stucco is a masonry product that is applied to the exterior of buildings as an attractive and weather resistant finish. Modern stucco is made by mixing cement, sand, and water together to form a paste. Manufacturers also include their own proprietary ingredients. Once applied to a building’s wall, it will dry to form a solid hard coating.

Stucco Application Process

Traditional Masonry Stucco is most commonly applied using the following basic method:

• A water resistant barrier is applied over top the of exterior sheathing (most often plastic “house wrap” over OSB plywood sheathing)

• Trim accessories are added around elements such as windows, door, and corners. Control joints are put in place to reduce cracking due to expansion and contraction.

• Then, a metal screen (lathe) is attached over top of the entire surface area of the wall. This gives the stucco something to adhere to.

• Finally, the Stucco is applied in (3) coats. A scratch coat, brown coat, and finish coat. The last coat can be tooled to achieve a variety of different textures and finished looks.

• Paint can be applied to stucco and is necessary to help to prevent moisture from entering the walls.

Why is stucco failing at an alarming rate?

All of the damage caused by defective stucco relates to one simple word – moisture. Two thing that Florida has in abundance are sunshine and moisture. Moisture is the most common cause of building degradation. It attacks the wood framing of a home causing decay and weakening of the structural integrity. Wood that remains wet is a perfect breeding ground for mold and fungus. So, why has stucco so often failed to protect buildings from moisture?

Water Intrusion

Moisture can seep through stucco in several ways. Bulk (liquid) moisture enters through cracks. Stucco can develop hairline cracks even under normal conditions. It may also enter around improperly sealed doors and windows. Incorrectly installed trim accessories provide another pathway for moisture.

Due to the many ways which water may infiltrate, stucco siding should not be considered a waterproof layer. This is also true of other siding options such as brick, hardie board, or vinyl. Once you accept that moisture will pass through stucco, you must make provisions that allow it to exit.

Improperly installed drainage system – Lack of air gap

A properly installed stucco siding system will have an air gap between the backside of the stucco and the wall sheathing (most often OSB plywood). This gap allows air movement behind the stucco. It also creates a “drain plane” that allows accumulated moisture, pulled by gravity, to drain down the wall. At the bottom of the walls should be drainage components known as “weep screeds”. This is where moisture needs to be able to exit the wall cavity. These drainage components should be found at the bottom of any vertical wall.

When stucco is applied without an air gap and drain plane, moisture that accumulates behind it remains trapped. It soaks into the wood framing and OSB plywood sheathing. Without the ability to dry, the wood rapidly molds and degrades. This can go on undetected for years. By the time evidence can be seen on the exterior surface of the stucco, the damage has already been done. This is the primary cause of stucco failures. Applicators who lack proper training and understanding of proper drainage often fail to provide an air gap and adequate drainage plane.

Stucco applied too thin

A correct stucco application results in a rendering that is 7/8″ thick. However, it is common to discover stucco applied as thin as 1/4″. Stucco this thin is prone to significant cracking and is much more permeable. Pair this with missing/incorrectly installed drainage provisions and you have a recipe for disaster.

Masonry (Hard Coat) Stucco vs. Synthetic (EIFS)

There are (2) siding systems that, when finished, are hard to distinguish from one another. Traditional hard coat stucco and “Synthetic Stucco” or EIFS (Exterior Insulation and Finish System). EIFS has the reputation of being more problematic and resulting in a greater number of failures than traditional hard coat.

EIFS has been the subject of several class action lawsuits. Plaintiffs allege that the EIFS siding system is inherently flawed. Synthetic stucco is much less permeable than masonry stucco. Moisture, even as a vapor, is not able to pass through the product layer. Because of its non-porous nature, it was considered to be a waterproof layer. Provisions for drainage were not thought to be necessary. Of course as you read earlier, moisture will inevitably penetrate. EIFS is not any better at keeping moisture out than masonry stucco. However, it is much better at keeping it trapped. This has led to a disproportionate number of failures in synthetic stucco homes. It is now recommended that all stucco, synthetic and masonry, be installed with an air gap and drainage.

Stucco Home Stigma

The current wave of stucco failures has really given stucco homes a bad reputation. This is especially true of homes clad in synthetic stucco. Some insurance companies will decline to write a policy on a stucco home. Relocation companies will often not allow transferees to purchase a home clad in stucco. Homeowners who go to sell their stucco home find that many buyers are wary and often end up discounting the price of their homes compared to similar non-stucco homes.

Should you avoid buying a stucco home then? Not necessarily. If you are someone who moves often then it could be problematic because stucco homes do tend to sit on the market a bit longer. However, if you plan to live in the home for awhile then you may be able to catch a great buy on a stucco home. Just be sure to have a thorough inspection performed prior to purchase.

Additional Inspections for Stucco Homes

If you are considering the purchase of a stucco clad property, you should definitely order a stucco inspection. This is a specialized and more intrusive inspection that goes above and beyond a typical home inspection. A certified stucco inspector will use methods such as:

• Infrared Thermal Imaging

• Electronic Moisture Scanning

• Invasive moisture testing

• Visual inspection to confirm drainage provisions

It is best to use an unbiased third-party inspection company that does not do remediation work. Some inspection companies will provide a warranty for your stucco.

Stucco Warranties

There are a variety of ways in which the stucco on a building may be warrantied. On new construction, the builder’s warranty should cover defects in workmanship. The state of Florida mandates that builders warranty their product against defects. Even if your builder does not offer a written warranty, one is implied under many states case laws, including Florida a state with many stucco Lawsuit cases. If a premixed stucco product is used then the manufacturer’s warranty should cover any problems with the material itself. (if applied according to the manufactures specifications)

On an existing structure, warranties can be purchased from specialized companies licensed and certified in your state. Offering a stucco warranty as a seller may reduce your time on market and preserve the value of your property. Buyers can purchase their own warranty if the seller is not offering one.

Summary

Thousands of stucco clad homes and building are silently rotting away only to be discovered once the damage is widespread. Repairs can often cost 20 – 40% of the value of the property. The problem is primarily due to defects in workmanship and not the product itself. Stucco applied without an air gap and provisions for drainage traps moisture inside of the wall cavity. Over time the moisture rots the plywood sheathing and framing components of the structure. Building officials do not examine the finished stucco as part of the normal inspection/permitting process. Untrained workers who were not being overseen applied stucco incorrectly to many homes during the Florida new construction boom. A stigma has developed among home buyers and real estate professionals in regards to stucco homes. A specialized moisture intrusion inspection is necessary when considering the inspection of a stucco clad property. Warranty options are available that will cover damage due to failed stucco siding.

Our products solve the recurrence of the cracks in stucco by creating a flexible, and permeable bond to the exterior of your home that will allow the moisture vapors trapped in your home to escape as needed.

Our certified crew repair any damage prior to the application process of one of our performance coatings.