Stucco is a popular exterior finish for homes, known for its durability and aesthetic appeal. While many people are starting to view fiber cement board as the new high-quality exterior finish, stucco is still one of our preferred choices at Leisure Villas. It is durable and requires less maintenance over time than painted surfaces like fiber cement board.
In Utah, since we experience a wide range of climate change, and since our homes are primarily built out of wood, this can affect your stucco. One of the most frequent questions we get, is: “What can I do about stucco cracks?”
Stucco Cracks
Stucco cracks can appear for various reasons, including natural settling of the house, temperature fluctuations, or improper installation. These cracks can range from tiny hairline fractures to more significant splits. Identifying the type and severity of the crack is the first step in determining the appropriate repair method. There are also different types of stucco applications, so for our purposes, we’ll be focusing on a hard-coat style of stucco application.
Most stucco cracks. A lot of people don’t like to hear this, especially if they have stucco cracks. Think of it like concrete—in your sidewalk, you have undoubtedly noticed that there are control joints built into the concrete. These lines that segment the sidewalk into squares are to control where the cracks happen, because concrete will crack. You see this most exterior concrete applications. If you look closely at those joints, you’ll notice that the concrete in many instances, did in fact crack in those areas.
Stucco is like concrete. When applied, it goes on wet, then hardens as it cures. As it hardens, it becomes more brittle and subject to cracking. Unlike concrete, there are very few control joints placed in stucco. This means that the cracks often go where they want, rather than following a pre-defined course.
Most Stucco Cracks Aren’t a Problem
The good news is that most stucco cracks are not a cause for alarm. Hairline cracks, which are less than 1/16 inch wide, are typically cosmetic and do not affect the structural integrity of your home.
Many people will insist on these small fractures to be caulked. While there is nothing structurally wrong with applying a stucco patch or acrylic caulk, these “fixes” tend to look worse than letting the cracks remain. I’ve visited homes before, where the homeowner did their best to match the color, yet they caulked every hairline crack in their wall, and a wall that looked perfectly fine now looks like a jig-saw puzzle that makes you think the whole wall is being held together by little more than glue and a good intentions.
How Is Stucco Applied?
Understanding how stucco is applied can help you appreciate why cracks might occur, and set your mind at ease when you see a crack. Stucco is typically applied in the following layers:
- Weather barrier: The first layer is a weather barrier. This might be done out of a couple layers of tar paper or some other membrane to keep water from penetrating to the wood behind.
- Lath: This is a wire mesh that is stapled onto the weather barrier. At Leisure Villas, we insist on our installers caulking in all the staples so that we maintain a weatherproof barrier.
- Brown Coat: This is a layer that somewhat resembles thin set. It is a cementitious layer that is troweled over the lath. As it hardens, the lath holds it in place. Once fully hardened, it acts much like concrete. This is the layer that is subject to cracking.
- Finish Coat: The final layer is the finish coat, which gives the stucco its texture and color. This layer is what you see on the exterior of your home. Naturally, if a crack develops in the brown coat, this will transfer through the finish coat.
As you can see, even when the brown coat receives a hairline crack, there is still a weather barrier behind it. This keeps the wood of your house safe from water penetration, as a crack in the cementitious layers rarely are able to transfer to the weather barrier.
When It Becomes a Serious Problem
While most stucco cracks are of minor concern, some can indicate more serious issues. Larger cracks, especially those wider than 1/8 inch, may suggest underlying structural problems. These cracks can allow moisture to penetrate the stucco, leading to water damage, mold growth, and even structural deterioration.
If you notice wide cracks, discoloration, or mold, it’s crucial to take action immediately. Here are the steps to address serious stucco cracks:
- Inspect for Moisture: Check for signs of moisture behind the stucco. This might involve using a moisture meter or consulting a professional.
- Consult a Professional: For significant cracks, it’s best to consult a stucco repair specialist or a structural engineer. They can assess the extent of the damage and recommend the best course of action.
- Repair and Seal: Depending on the severity, repairs might involve removing the damaged stucco, addressing any underlying issues, and reapplying the stucco layers. Ensure that the repaired area is properly sealed to prevent future moisture intrusion.
In our experience, most stucco issues that actually required a repair came from one of two causes: a water penetration above the stucco, such as from bad flashing of the roof or soffits; the other cause is from somebody crashing their car into the stucco wall.
Conclusion
Stucco cracks are a common issue but unless the gap is so large that water is getting in, freezing and chipping away at the stucco, they are more often than not, better left alone. By understanding the types of cracks and their implications, you can maintain the integrity and appearance of your stucco, ensuring it continues to protect and beautify your home for years to come.