How to Identify, Assess, and Repair Cracks in Buildings
Published: 03 Mar 2025
Building cracks can be worrying, but not all cracks are the same. Some are harmless, while others could signal serious structural problems. Identifying, assessing, and repairing cracks is key to keeping your home or building safe and secure.
This guide will walk you through the steps to spot dangerous cracks, understand their causes, and take the right action to Repair Cracks. Whether it’s a small crack in the wall or a more significant issue in the foundation, you’ll learn how to handle it effectively.
By the end, you’ll know when to Repair Cracks yourself and when to call in a professional. Let’s dive in and ensure your building stays strong and stable for years.
How to Identify and Assess Cracks in Your Building
Not all cracks in your building are the same. Some are harmless, while others could signal serious problems that need immediate attention. It’s essential to know how to identify and assess cracks so you can decide whether they need professional help. Here’s how you can do it.
How to Spot Dangerous vs. Cosmetic Cracks
Cracks can appear anywhere, but not all of them are a cause for concern. Knowing the difference between a cosmetic crack and a dangerous one is key.
- Cosmetic Cracks:
These are usually small, shallow cracks that don’t affect the building’s structure. They are often the result of normal settling, temperature changes, or minor humidity issues. Cosmetic cracks are common in drywall and plaster. - Structural Cracks:
These cracks are more serious. They may be more significant, more profound, or growing over time. Structural cracks often show up in places like the foundation, load-bearing walls, or ceilings. If the cracks change shape, widen, or let water in, they could indicate an underlying structural problem. - Key Signs of Dangerous Cracks:
- Cracks wider than 1/8 inch
- Cracks that are diagonal or horizontal in the foundation
- Cracks that appear near windows, doors, or corners
- Water leaking through cracks
- Visible movement or bulging of walls or floors
How to Identify Cracks in Walls, Ceilings, and Foundations
Cracks can appear in various places, and the location often gives clues about their seriousness.
- Walls and Ceilings:
Look for small, vertical, or hairline cracks. These are often not serious. However, pay attention to large cracks, predominantly horizontal or diagonal ones. Cracks near doors and windows are also a red flag. - Foundation Cracks:
Foundation cracks can be more concerning, especially if they are horizontal or widen over time. Small vertical cracks are usually normal, but horizontal cracks could indicate pressure or movement in the foundation. - What to Look For:
- Vertical cracks in walls: These are often settling cracks, which are usually harmless.
- Diagonal or horizontal cracks are more serious and may indicate structural issues.
- Cracks in the foundation: Pay attention to their size and location. Widening cracks or cracks that leak water are more concerning.
Using Crack Monitors to Track Cracks
If you’re worried about a crack, you can track its growth over time to see if it’s worsening.
- What is a Crack Monitor?
A crack monitor is a small, inexpensive tool that you can stick on the crack. Its scale measures the width of the crack, allowing you to track whether it grows, stays the same, or is shrinking. - How to Use a Crack Monitor:
- Stick the monitor on the crack in an area where you can easily see it.
- Mark the current position of the crack.
- Check the crack regularly to see if it’s changing.
- Measure the width and note any changes over time.
- When to Use One:
If you notice a crack and want to keep an eye on it, a crack monitor can give you valuable information. If the crack grows or changes, it’s time to call a professional.
When to Contact a Professional Based on Crack Behavior
It’s important to know when a crack is something you can fix yourself and when it’s time to call in a professional.
- Signs You Need Professional Help:
- The crack is widening over time.
- You notice water or moisture coming through the crack.
- The crack is large, horizontal, or diagonal, especially in the foundation.
- The crack is accompanied by other signs of damage, like sloping floors or doors/windows that don’t close properly.
- You’re unsure about the severity of the crack and want an expert opinion.
A professional, such as a structural engineer or contractor, can assess the crack, determine the cause, and recommend the right solution.
By monitoring cracks in your building, you can take action before minor issues become big problems. If you are ever in doubt, don’t hesitate to contact a professional to ensure your building remains safe and stable.
Solutions and Repairs for Cracks in Buildings
Cracks in your building can be concerning, but the good news is there are solutions for many of them. Whether it’s a small crack in the drywall or a more significant foundation issue, you can take steps to fix the problem.
Here’s a guide to help you handle cracks and ensure your building stays strong and safe.
Fixing Minor Cracks
Small cracks, like those in drywall or plaster, are easy to repair.
- DIY Methods for Minor Cracks:
- Use a putty knife to fill the crack with joint compound for Drywall Cracks. Smooth it out, let it dry, and then sand it smooth. Finally, paint over the area to match the rest of the wall.
- For larger Plaster Cracks, Use a plaster patching compound. Apply the compound, smooth it out, and allow it to dry before sanding and painting.
These simple repairs can fix hairline or small settling cracks and prevent them from worsening.
Repairing Structural Cracks
Structural cracks, particularly in foundations or load-bearing walls, are more serious and usually require professional help.
- Professional Solutions for Structural Cracks:
- Epoxy Injections: This method is often used to seal foundation cracks. Epoxy is injected into the crack, filling it and restoring the wall’s strength.
- Carbon Fiber Straps: Carbon fiber straps can be applied to cracks in walls or foundations to reinforce the structure and prevent further damage.
- Wall Anchors: In some cases, wall anchors can pull shifting walls back into place and provide long-term support.
Structural cracks require careful attention, and hiring an expert specialising in foundation or structural repairs is always best.
How to Repair Foundation Cracks
Foundation cracks are a significant concern, but various methods exist to fix them.
- Epoxy Injections are used to fill cracks and prevent water from leaking through. This method is effective for repairing small to medium cracks in the foundation.
- Underpinning: If the foundation has settled or shifted, underpinning may be necessary. This involves strengthening the foundation by adding new support beneath it.
- Foundation Stabilization: Stabilization methods such as helical piers or steel beams can reinforce the structure in severe shifting or bowing foundation walls.
To determine the best solution, it’s essential to evaluate the size and severity of the crack. For larger cracks or cracks that allow water in, always contact a foundation repair expert.
When to Seek Professional Help
Some cracks can be repaired quickly, but others require expert intervention. Here’s when you should call in the professionals.
- Guidelines for Seeking Professional Help:
- Large or Widening Cracks: Call a professional if the crack is more significant than 1/8 inch or grows over time.
- Cracks in Load-Bearing Walls or Foundations are more serious and can affect the building’s overall stability.
- Water Leaking Through Cracks: Water coming through a crack could be a sign of water damage or foundation issues that must be addressed immediately.
- Visible Movement or Bulging Walls: If you notice bulging walls or sloping floors, it could signify significant structural damage.
A structural engineer or foundation repair specialist can assess the problem and recommend the right action.
Long-Term Solutions
Preventing cracks from returning is as important as fixing the ones you already have.
- Preventative Measures and Repairs:
- Proper Drainage ensures water flows away from the foundation. Poor drainage is one of the leading causes of foundation cracks.
- Soil Stabilization: If your soil is unstable or shifting, consider soil stabilisation techniques to prevent foundation problems in the future.
- Regular Inspections: Inspect your building periodically to catch small cracks before they become big problems.
- Repairing the Root Causes: If cracks are caused by moisture or settling, fix the underlying issues, such as leaks or improper settling, before they cause more damage.
Addressing the root causes of cracks can keep your building in good shape for years.
FAQs
1. How to assess building cracks?
- Inspect the crack: Check its size, shape, and location.
- Monitor changes: Use a crack monitor or mark the crack to track if it’s growing.
- Look for signs of damage: Check for water leaks, bulging walls, or uneven floors.
- Consult a professional: If the crack is large, widening, or in a critical area like the foundation.
2. How to identify structural cracks?
- Look for key signs: Horizontal or diagonal cracks, cracks wider than 1/8 inch, or cracks near load-bearing walls or foundations.
- Check for movement: Bulging walls, sloping floors, or doors/windows that don’t close properly.
- Monitor water leaks: Cracks that let water in are often structural.
3. How do you repair cracks in a building?
- Small cracks: Fill with joint compound, plaster, or sealant.
- Larger cracks: Use epoxy injections or patching materials.
- Structural cracks: Seek professional help for solutions like carbon fiber straps, wall anchors, or underpinning.
4. How do you monitor building cracks?
- Use a crack monitor: A small tool that measures crack width over time.
- Mark the crack: Use a pencil or tape to track changes.
- Take photos: Document the crack’s progress regularly.
5. How do you diagnose cracks?
- Examine the crack: Note its size, shape, and location.
- Check for causes: Look for signs of settling, moisture, or temperature changes.
- Consult a professional: A structural engineer can assess the crack’s impact on the building.
6. How do you check for cracks?
- Inspect walls, ceilings, and foundations: Look for visible gaps or splits.
- Use a flashlight: Shine light along surfaces to spot small cracks.
- Check for signs of damage: Water leaks, bulging walls, or uneven floors.
7. How to check cracks in walls?
- Look for patterns: Vertical cracks are often harmless, while horizontal or diagonal cracks may be severe.
- Measure the width: Use a ruler or crack monitor to check if the crack is widening.
- Monitor changes: Track the crack’s growth over time.
8. What tool is used to measure cracks?
- Crack monitor: A small, adhesive tool with a scale to measure crack width.
- Caliper or ruler: For manual measurement of crack size.
9. How do you detect cracks in concrete?
- Visual inspection: Look for visible gaps or splits.
- Tap test: Use a hammer to tap the concrete, hollow sounds may indicate hidden cracks.
- Use a crack monitor: To measure and track crack width.
10. Who assesses cracks in walls?
- Structural engineers: Experts who evaluate cracks and determine their impact on the building.
- Contractors or foundation specialists: Professionals who can repair cracks and address underlying issues.
Conclusion
Cracks in buildings can be worrying, but with the proper knowledge, you can handle them effectively. By learning to identify, assess, and repair cracks, you can protect your home or building from serious structural issues. Remember, small cracks are often harmless, but larger or growing cracks may need professional attention.
Regular inspections and timely repairs are key to keeping your building safe and stable. Whether it’s a minor crack in the wall or a major foundation issue, taking action early can save you time, money, and stress in the long run.
If you are ever unsure about a crack, don’t hesitate to call a professional. With proper care, you can ensure your building stays firm and secure for years. Stay vigilant, stay informed, and keep your structure in great shape!
