Stucco cracks when it expands, shrinks, or shifts more than it should. These movements occur when the wall dries too quickly, is subjected to extreme cold or heat, or isn’t applied properly in the first place. If the base coat dries unevenly or the cement mix is too weak, small gaps start to form. These cracks can grow larger over time if water seeps in and freezes.
Even normal things like a settling foundation or nearby traffic vibrations (called seismic stress) can cause stucco to crack. Some cracks are thin and shallow, while others go deeper and may mean the wall is damaged underneath. Most stucco cracks form near corners, around windows, or in places where the wall bends or flexes more than usual.
This guide helps you understand why your stucco is cracking, so you know what to do for repairs. If you still have more questions or need stucco crack repair in Edmonton, AB, call (780) 710-3972.
Poor Stucco Installation Leads to Early Cracking
Stucco cracks when it’s not applied correctly during installation. If the stucco mix is too dry or too wet, it won’t set properly. Bad weather, such as hot sun, wind, or freezing cold, also interferes with drying. If workers rush the job or skip steps like layering and curing, it can cause hairline cracks to appear weeks after installation.
Sometimes the stucco coat is too thin or too thick, and that also weakens the wall. Proper stucco installation requires clean surfaces, metal lath or fiberglass mesh, even layers, and a correct drying time.
Wrong Stucco Mix or Thin Coats Increase the Risk of Cracking
Stucco cracks when the mix lacks the right balance of cement, sand, water, and bonding agents.
A weak mix or poor surface bonding creates a fragile wall. Also, if the base coat is too thin, it can’t hold up over time. A good stucco mix must be applied in layers with the correct thickness and pressure. In colder climates like Edmonton, using the wrong type of stucco or skipping reinforcement mesh will increase the risk of early cracking.
Foundation Settling Causes Vertical Stucco Cracks
Stucco cracks when your home’s foundation shifts or settles unevenly. This stress pulls the surface in different directions.
When a house settles, the movement puts pressure on stucco walls, especially at corners and window frames. This usually creates vertical stucco cracks or step-pattern fractures. These cracks are wider at the top and follow the stress line. Foundation settling is common in Edmonton due to soil moisture changes. You might see these cracks months or years after construction.
Moisture Intrusion Weakens Stucco From Inside
Stucco cracks when water gets behind the wall and breaks down the inner layers. This is called moisture intrusion.
Water from rain, snow, or plumbing leaks can sneak in through gaps or flashing failures. Over time, this causes the base coat to swell and crumble. You might see bubbling, peeling paint, or bulging areas on your wall. If the wall feels soft or sounds hollow when tapped, moisture is likely trapped behind it. This can lead to bigger problems if ignored.
Freezing Weather and Temperature Changes Cause Stucco Cracking
Freezing weather and big changes in temperature cause stucco cracking. In Edmonton, the weather goes from warm to freezing very fast. When water gets into small cracks and freezes, it turns to ice and pushes the stucco out. This happens again and again, making the cracks worse. You might see spider cracks, flaking, or big chunks breaking off. Acrylic stucco bends better than cement stucco, but both need sealing to keep water out in winter.
Drying Too Fast Causes Surface Hairline Cracks
Stucco cracks when it dries too fast after application, especially in hot, dry, or windy weather.
When the top layer dries faster than the inside, it causes tiny surface fractures called hairline cracks. These are thin but common. If the wall wasn’t misted or shaded properly after application, the surface becomes brittle. Cracks like these might not cause structural issues, but can allow moisture to enter over time.
Ground Shaking or Vibrations Can Crack Stucco
Stucco cracking occurs when the ground moves or nearby vibrations shake the wall. This can happen during small earthquakes, heavy traffic, or nearby construction. The shaking puts pressure on the stucco, which makes it crack in lines or steps across the wall. Homes near highways or busy work areas get these cracks more often, especially on tall or narrow walls.
Bad Window and Door Joints Can Make Stucco Crack
Stucco cracks around windows and doors when builders don’t install proper joints. These areas move more than flat walls because of how frames shift with temperature and pressure.
Stucco needs special joints, called expansion joints, to let the wall move without cracking. If those joints are missing or badly done, the stucco can’t stretch. That’s when you start to see spider cracks or lines where the stucco pulls away at the corners. These spots are some of the first places where damage shows up, especially in homes with poor stucco installation.
Stucco Restoration vs. Patching: Which One Solves Cracking for Good?
Stucco restoration solves long-term cracking better than patching because it treats the root cause, not just the surface.
Patching is useful for small surface repairs, like fixing shallow dents or sealing hairline damage on newer walls. It works best when stucco cracking is limited and hasn’t affected the base layers. However, patching doesn’t address deeper issues like moisture buildup, structural failure, or expansion stress. If patching is done over stucco that’s already compromised, the cracks often come back.
Stucco restoration is more thorough. It involves removing damaged sections, checking for water damage or mould behind the wall, and rebuilding with proper mesh, drainage layers, and coatings. You likely need complete stucco restoration if:
- You see horizontal stucco cracks running across the wall. These usually come from movement or stress behind the surface.
- Gaps are forming near the ground. This could be from foundation settling as the house slowly shifts.
- You notice dark spots, bubbling, or soft plaster. These are signs of water intrusion in stucco cracks that might be hidden inside the wall.
These problems usually start small but worsen when left untreated, especially during Alberta’s freeze–thaw cycles or in homes with poor flashing.
Another cause of widespread gaps is thermal expansion that causes stucco cracks. When walls heat up and cool down too fast, like on south-facing sides, restoration becomes necessary to prevent future repairs. If there’s damaged drywall inside or signs of shifting walls, patching won’t fix the problem. That’s when complete repair with restoration protects your home and helps the finish last longer.
If you’re dealing with isolated cracks, patching might work. However, if cracking persists or spreads rapidly, restoration is a more reliable solution.
Depend Exteriors Offers Stucco Repair in Edmonton AB
Stucco cracking in cold weather is common in Edmonton, especially when moisture gets trapped and freezes. That’s why Depend Exteriors focuses on repairing damage before it spreads.
We handle everything from minor cracks to large sections of failed stucco. If your wall shows signs of blistering, soft spots, or crumbling edges, these may indicate deeper moisture issues. Our process includes inspecting for hidden damage, sealing weak areas, and matching the texture to ensure repairs blend in perfectly. Call (780) 710-3972 for a full inspection.
FAQs
Is there a difference between spider cracks and hairline cracks in stucco?
Hairline cracks are straight, thin lines caused by shrinking or drying too fast. Spider cracks look like a web and usually form from pressure or surface stress. Both types of cracks may seem small, but they lead to bigger problems if water gets in.
What causes hairline cracks to show up after stucco installation?
Hairline cracks often appear when the stucco wasn’t mixed or cured properly during installation. If the coat dries too fast or is too thin, it can shrink and leave tiny lines across the wall. These cracks usually show up within weeks of finishing the job.
Are spider cracks in stucco a sign of deeper damage?
Yes. Spider cracks can mean more than just surface issues. If you see web-like cracks spreading out in different directions, it might be from poor bonding or pressure inside the wall. It’s best to check early so the damage doesn’t grow worse.
Why is my stucco cracking around windows and doors?
Your stucco may be cracking near windows and doors because of weak joints or missing expansion gaps. These areas move more than flat walls, making them more likely to crack if not installed correctly.
What does stucco cracking repair involve?
Stucco cracking repair usually includes grinding out the damaged area, adding mesh, and applying new stucco that matches the texture. For deep or spreading cracks, moisture checks and base repairs might also be needed.
What are the most common causes of stucco cracks in homes?
Stucco cracking is caused by things like poor installation, foundation movement, moisture trapped behind the walls, or extreme temperature changes. Over time, these issues create minor cracks or larger gaps that need attention.
Can you prevent stucco cracks from forming in cold climates?
Yes, you can help prevent stucco cracking by using flexible coatings, sealing gaps, and choosing the right materials for cold-weather performance. Regular checks for moisture buildup and movement also reduce the chances of cracking over time.
