All stucco walls have cracks. They may be hairline and only noticeable on close examination, but they are there. The only time we inspect stucco that doesn’t have any cracks is shortly after the homeowner has had the walls caulked and painted. 

Let’s start with the width of the crack:

• Hairline - Can be sealed with a coat of paint if exposed to the weather, but no repair necessary if not. Monitor to be sure that it does not continue to open.
• 1/16” - Caulking or masonry caulk recommended. Again, check later to confirm that it does not open further. 
• 1/8” to 3/16” - Cracks of this diameter are considered very likely to be structural, and we recommend evaluation for cause, and monitoring after repair. Any crack with surface differential (one side forward of the other) indicates a structural problem, except that buckling of the both sides (as in the photo above) is more likely to be result of a moisture issue in the wall.
• 1/4” and above - Definitely a structural problem, requiring evaluation and repair.

    Is it a concrete block wall with a stucco finish, or stucco over a wood frame wall? See our blog post How can I tell if the exterior walls of a house are concrete block (CBS) or wood or brick? when you are not sure which one. If the wall is stucco over wood frame, go to Why is my stucco cracking? for problems that cause cracking with this type of wall construction.

What direction does the crack run?

• Diagonal - See our blog post What causes stair-step cracks in a block or brick wall?
• Horizontal -  See our blog post What causes a horizontal crack in a block or brick wall?  
• Vertical - See our blog post What causes a vertical crack in an exterior concrete block or brick wall?
• Along Concrete Tie Beam - See our blog post There's cracks running along the home's concrete tie beam. What's wrong?  

    If you plan on checking your walls carefully for cracks, see our blog post Where are the places to look to find structural cracks in a house? and How do I recognize serious structural problems in a house? for tips on where and how to look. And, if you want to monitor the problem to see if it is progressing, read How can I tell if cracks in the wall or floor are getting worse or staying the same? 

    Although crack patterns can often lead you directly to the underlying problem, sometimes a more in-depth analysis is necessary. See our blog post How do you analyze a crack from cause to effect? for more on this.

    Then again, sometimes you don’t need any special training to recognize a structural problem in a stucco wall.

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To learn more about exterior walls and structures, see these other blog posts: 

• How do I pick the right contractor to fix my stucco?

• What is the average lifespan of a house foundation?

• What causes vertical cracks in fiber cement siding planks?

 • What causes raised white lines of residue on a block wall that are crusty and crumbling? 

• What is the difference between soil subsidence, heave, creep, and settlement? 

• How much ventilation is required for the under-floor crawl space of a home? 

• How can I tell if a diagonal crack in drywall at the corner of a window or door indicates a structural problem?

• What causes the surface of old bricks to erode away into sandy powder? 

• What are the pros and cons of concrete block versus wood frame construction?

• Should I buy a house with a crawl space? 

• Why is my stucco cracking? 

• What would cause long horizontal lines of brick mortar to fall out?

• How do I recognize structural problems in a retaining wall? 

• What is engineered wood siding?

• Should I buy a house that has had foundation repair? 

• What is a "continuous load path”?

• Should I buy a house with asbestos siding?   

• How can I tell if cracks in the garage floor are a problem or not? 

• What do you look for when inspecting vinyl siding?

• Why is housewrap installed on exterior walls under the siding? 

• Why did so many concrete block homes collapse in Mexico Beach during Hurricane Michael? 

• How can I tell if the concrete block walls of my house have vertical steel and concrete reinforcement?

• Should I buy a house with structural problems? 

• What are those powdery white areas on my brick walls?

• What causes cracks in the walls and floors of a house?

• How can I tell if the exterior walls of a house are concrete block (CBS) or wood or brick?

• What are the common problems of different types of house foundations? 

• What are the warning signs of a dangerous deck?

    Visit our EXTERIOR WALLS AND STRUCTURE page for other related blog posts on this subject, or go to the INDEX for a complete listing of all our articles.