Stucco siding has been around for decades and continues to remain a popular choice in many regions of the country. Despite its many wonderful qualities, you may often hear about stucco failure. While failure does occur sometimes, it is usually due to an identifiable and preventable reason. Thus, it is possible to avoid major stucco failure. However, it is important to understand common issues that impact stucco and how to avoid bigger problems. Continue reading to learn more about the ins and outs of stucco siding.
What is the main problem with stucco?
While there are several reasons that stucco may fail, one of the most significant reasons for failure is improper installation. Improper installation in and of itself, does not cause failure but the residual impact of poor craftmanship, leads to problems that may eventually cause complete failure of the stucco. Once this occurs, you can count on issues related to deterioration and the necessity of costly repairs.
The Impact of Thermal Resistance
You may be aware of the sturdy and durable stucco of years past and wonder how a contractor could mess this up. For one thing, the energy movement across assemblies has been reduced, in recent years, due to something called thermal resistance. In layman's terms this simply means walls are better insulated in modern times then they were in the past. While this is a positive for energy savings, this better insulation keeps heat from drying out necessary parts of the wall assembly and stucco. As such, it is necessary that stucco's absorption of moisture must be reduced, in order to compensate for its reduced ability to dry.
Understanding Reservoir Cladding
Stucco has properties of absorption, better known as reservoir cladding in the siding world. Simply put, stucco absorbs much more water during a rain or snowstorm than other siding options available. Thus, it is necessary for water to properly evaporate. When this cannot happen, water issues will be the secondary impact.
With this in mind, it is critical that the correct type of sheathing is used during the installation process. If a contractor chooses gypsum sheathing, there will be problems down the road because it is overly vapor permeable. The converse is true of OSB sheathing, which is vapor impermeable, causing another set of issues.
This may all sound a bit confusing, but it is a simple principle. Reservoir cladding releases internally, allowing vapor to easily penetrate through the permeable nature of the gypsum sheathing. Once, it has fully penetrated the sheathing, it has nowhere else to go but into the wall cavity and interior finishes, leading to damage.
On the other hand, when OSB sheathing is used, it prevents the wall assembly from drying out properly leading to moisture related damage.
Stucco materials have changed greatly since its introduction. Thus, modern day stucco is vastly different in composition than those used in years past. Henceforth, these changes require contractors to adapt and use different techniques for stucco installation in order to mitigate moisture issues.
Simply put, due to the changes in modern day stucco composition, moisture sticks around longer. The natural consequences are issues of rot, mold, loss of structural integrity, shifting, and cracking, which are all symptoms of a larger failure.
Thus, is imperative that stucco contractors are aware of the importance of keeping moisture from penetrating behind the stucco and causing decay to the underlying structure. To ensure a dry underside, contractors must be properly educated on methods that prevent moisture from getting behind and ruining the structural integrity of a building.
Mitigating the Problem
Despite these changes in the composition of stucco, a skilled stucco contractor will employ a method that will allow for proper drainage to occur. This is typically achieved by adding a drainage mat, sandwiched between the WRB and the bond break. The stucco is also suspended from the wall, with the addition of a vented/drained airgap. When these measures are properly implemented, moisture will no longer be able to infiltrate behind.
Improper stucco installation is often first evidenced when issues of moisture appear. Very often, serious, and costly damage will occur as a direct result of moisture penetration. Moisture itself is a secondary impact of improper installation; however, it also causes additional residual impacts like rot, mold, and decay. If moisture penetration is left unresolved for extended periods of time, it will ravage a structure, subsequently weaken it, and steal its beauty.
Initially you may be blissfully unaware that your stucco has a moisture problem. However, given enough time, it will present itself clearly in multiple manifestations. Some identifying marks of water damage include dark spots, foul odors, cracking, missing sections, stained or discolored areas, and bulging. You should also be aware of any staining that appears under windows as this is often a clear indicator that water damage is occurring behind your stucco. Sadly, by the time you realize what is occurring the damage is likely already done.
If you've noticed any of these alarming signs, it is crucial that you speak with an experienced stucco contractor as soon as possible. Allowing the damage to continue further will eventually take its toll on the structural integrity of your home. Not to mention, the serious nature of black mold that can lead to a series of severe medical conditions. If the damage done is not yet too severe, a skilled contractor can restore your stucco so you can get on with living.
A Job Done Right
Despite all the potential failures that can result when stucco is not installed properly, when done right, stucco can be one of the most long-lasting siding options available on the market today. Stucco provides a timeless elegance to any home or business. It also offers many practical and attractive benefits like durability, fire resistant properties, and curb appeal. It remains one of the top choices for homeowners across America, year after year.
If fear of stucco failure has been holding you back, you can rest assured that a job completed by a trained stucco contractor will result in a hardy and attractive exterior for years to come!