Cracks in your home’s stucco can be concerning. They often raise questions about potential underlying issues, such as problems with the foundation. While not all stucco cracks indicate a serious problem, some can indeed be a sign of foundation issues.
Understanding the types of stucco cracks, their causes, and when to take action is crucial for maintaining your home’s structural integrity.
Understanding Stucco and Its Purpose
Stucco is a popular home exterior finish known for its durability and aesthetic appeal. It is made from a mixture of cement, sand, and water, sometimes with the addition of lime plaster additive. Stucco is applied in multiple layers over a lath (a framework of wood or metal) to create a hard, protective surface. This material is valued for its ability to withstand harsh weather conditions and its versatility in achieving various textures and finishes.
Types of Stucco Cracks
Not all cracks in stucco are created equal. They can vary in size, pattern, and location, each potentially indicating different underlying issues. Here are some common types of stucco cracks:
- Hairline Cracks: These are very thin cracks, usually less than 1/16 inch wide. Hairline cracks are often caused by the natural settling of the house, minor shrinkage of the stucco as it cures, or slight movements in the foundation that are not necessarily problematic.
- Spider Cracks: These cracks resemble a spider web and are usually caused by the rapid drying of the stucco or improper application. While spider cracks may not always indicate serious issues, they can allow moisture to penetrate the stucco, potentially leading to more significant problems over time.
- Diagonal Cracks: Cracks that run diagonally across the stucco surface can be more concerning. They often indicate structural stress and movement, which could be related to foundation issues. Diagonal cracks are commonly found around windows and doors, where structural weakness is more likely.
- Horizontal and Vertical Cracks: These cracks can be signs of significant foundation movement. Horizontal cracks may indicate shifting or settling, while vertical cracks could suggest that the foundation is sinking or heaving.
- Map Cracking: This type of cracking resembles a road map and is typically caused by the shrinkage of the stucco material. While not always a sign of foundation issues, map cracking can lead to moisture infiltration if not addressed.
Causes of Stucco Cracks
- Natural Settling: All houses settle to some extent over time. This settling can cause minor cracks in the stucco, particularly hairline cracks, which are generally not a cause for concern.
- Foundation Movement: Significant movement of the foundation, such as settling, shifting, or heaving, can lead to larger and more serious cracks in the stucco. This movement can be caused by various factors, including soil conditions, water drainage issues, and seismic activity.
- Improper Application: If the stucco is not applied correctly, it can lead to cracks. This includes issues such as insufficient curing time between layers, incorrect mixing of materials, or inadequate application techniques.
- Weather Conditions: Extreme weather conditions, such as heavy rain, freeze-thaw cycles, and intense heat, can cause the stucco to expand and contract, leading to cracks.
- Structural Stress: Areas of the house that experience significant structural stress, such as around windows and doors, are more prone to cracking. This stress can be due to normal use, such as opening and closing windows and doors, or more significant structural issues.
When Do Stucco Cracks Indicate Foundation Issues?
Not all stucco cracks indicate foundation problems, but some can be. Here are some indicators that your stucco cracks may be related to foundation issues.
The first indicator you want to look for is the location of the cracks.
Cracks around windows, doors, and corners of the house can be more concerning, especially if they are diagonal or extend from the corners. Next, you want to look at the size and width of the cracks…
Larger cracks, typically wider than 1/16 inch, are more likely to be related to foundation issues. If you notice that the cracks are growing over time, it could be a sign of ongoing foundation movement.
You also want to look around your house for other signs of foundation issues:
- Uneven or sagging floors
- Sticking doors and windows
- Gaps between walls and ceilings
- Tilting or leaning chimney
- Bowing or bulging basement walls
- Water leaks in the basement
What to Do if You Suspect Foundation Issues
If you suspect that your stucco cracks are related to foundation problems, you need to take immediate action. It’s unsafe to live in a home with dangerous foundation issues. If you want to sell your home with foundation issues, it’ll usually command 10-15% less.
The first thing you need to do is consult a professional.
Contact a qualified foundation specialist or structural engineer to assess your home’s foundation. They can perform a thorough inspection and recommend foundation repairs if needed.
In the meantime, you want to do immediate damage control.
This means addressing water drainage issues which can compound the structural instability. Ensure that your gutters and downspouts are functioning correctly and direct water away from your home’s foundation. Consider grading the soil around your home to slope away from the foundation.
From there, follow the structural engineer’s recommendations. Remember that fixing cosmetic issues like stucco cracks will NOT fix your foundation.
Once any foundation issues have been addressed, you can repair the stucco cracks. For minor cracks, you can use a stucco repair product to fill and seal the cracks. For larger or more extensive cracks, you may need to hire a professional to reapply the stucco.