When to Worry: Reading Foundation Cracks in Your Michigan Home
- Erik Hodge
- 4 days ago
- 8 min read
Part 3 of 3: A Visual Guide to Foundation Crack Assessment
Not All Cracks Are Created Equal
At HHI Services, one of the most common question we get during basement inspections is: "Is this crack bad?"
The answer? It depends.
Some cracks are normal settling. Others indicate serious structural problems requiring immediate attention. Learning to read foundation cracks can save you thousands in unnecessary repairs—or alert you to problems before they become catastrophic.
This guide will help you understand what you're looking at and when to call a professional.
Missed the earlier parts?
The Three Factors That Matter Most
When evaluating any foundation crack, consider:
1. Direction and Pattern
Vertical cracks: Often least concerning
Horizontal cracks: Most serious
Stair-step cracks: Potentially serious
Random pattern: Can indicate widespread issues
2. Width
Hairline (under 1/16"): Usually minor
Narrow (1/16" - 1/8"): Monitor
Medium (1/8" - 1/4"): Evaluate professionally
Wide (over 1/4"): Professional evaluation needed
3. Movement
Static: Hasn't changed in years (lower concern)
Growing: Getting wider or longer (major concern)
Seasonal: Changes with seasons (may be normal or problematic)
Pro Tip: Take dated photos with a ruler for scale every 3-6 months. Document any changes.
Vertical Cracks: Usually Least Concerning
Characteristics:
Run straight up and down
Common in poured concrete foundations
Often appear in first few years after construction
Usually result from concrete curing and shrinking
Typical Causes:
Concrete shrinkage during curing
Settlement in first 1-2 years
Temperature changes
Minor foundation movement
When Vertical Cracks Are Okay:
✓ Hairline to 1/8" wide
✓ Not growing over time
✓ No water intrusion
✓ No displacement (both sides at same level)
✓ Appear within first few years of construction
When to Worry About Vertical Cracks:
⚠ Wider than 1/4"
⚠ Growing over time
⚠ One side displaced from other
⚠ Water leaking through
⚠ Multiple cracks throughout basement
⚠ Accompanied by other issues (sticking doors, etc.)
Action Plan:
Under 1/8": Monitor annually, seal if water intrusion
1/8" - 1/4": Monitor quarterly, consider professional evaluation
Over 1/4": Professional structural evaluation
Any width but growing: Professional evaluation
Cost to Seal: $300-600 typical
Cost if Ignored and Structural: $2,000-10,000+
Horizontal Foundation Cracks: MOST SERIOUS
Characteristics:
Run horizontally across wall
Often accompanied by inward bowing
Indicate lateral soil pressure
Most common 4-8 feet below grade
What Causes Horizontal Cracks:
Hydrostatic pressure from saturated soil
Freeze-thaw expansion of soil
Poor drainage around foundation
Clay soil expansion
Can lead to wall failure if not addressed
Why They're Serious:
Foundations are designed to carry vertical loads (weight of house). Horizontal cracks indicate lateral pressure that foundations aren't designed to handle. This can lead to:
Progressive wall bowing
Wall collapse (in extreme cases)
Catastrophic structural failure
Unsafe living conditions
Warning Signs with Horizontal Cracks:
🚨 Call Professional Immediately If:
Crack is horizontal
Wall is bowing inward (even slightly)
Crack is at 4-8 feet below ground level
Multiple horizontal cracks
Crack is wider than 1/8"
Any horizontal crack with water intrusion
Action Plan:
ANY horizontal crack = professional evaluation ASAP
Do not wait. Do not "monitor." Get a structural engineer or foundation specialist immediately.
Repair Options:
Carbon fiber straps: $300-600 per strap, multiple needed
Wall anchors: $400-800 per anchor, multiple needed
Steel I-beams: $400-1,000 per beam, multiple needed
Wall replacement (worst case): $10,000-30,000+
Average Stabilization: $5,000-15,000 depending on severity
Important: These repairs typically stop further movement but don't straighten walls. Address when bowing is minimal.
Stair-Step Cracks: Potentially Serious
Characteristics:
Follow mortar joints in block foundation
Create step/zigzag pattern
Can be horizontal, vertical, or diagonal overall direction
Common in block (CMU) foundations
What Causes Stair-Step Cracks:
Differential settlement (one part settling more than another)
Expansive soil pressure
Poor compaction during construction
Inadequate footing
Tree roots (occasionally)
When Stair-Step Cracks Are Concerning:
⚠ Width over 1/4"
⚠ Growing over time
⚠ Accompanied by sticking doors/windows
⚠ Wall displacement visible
⚠ Cracks extending to other areas
⚠ Gaps at mortar joints
When They May Be Okay:
✓ Very narrow (under 1/8")
✓ Appeared in first year, haven't grown
✓ Limited to one corner
✓ No other signs of problems
✓ No water intrusion
Action Plan:
Under 1/8" and stable: Monitor semi-annually, tuckpoint mortar if needed
1/8" - 1/4": Professional evaluation recommended
Over 1/4": Professional evaluation required
Growing: Immediate professional evaluation
Tuckpointing Cost: $300-800 Foundation Repair: $2,000-10,000+ if structural
Diagonal Cracks: Evaluate Carefully
Characteristics:
Run at angle (typically 30-45 degrees)
Often from corner of window, door, or foundation
Can appear in poured concrete or block
Common Causes:
Settlement (normal in first 1-2 years)
Stress concentration at corners
Differential settlement
Foundation movement
Assessment:
Diagonal cracks require case-by-case evaluation:
From corner, narrow, not growing: Likely settlement, monitor
Wide or growing: Potentially serious settlement issue
Multiple diagonal cracks: Indicates widespread movement
Action Plan:
Hairline and stable: Monitor annually
Over 1/8" or growing: Professional evaluation
Multiple diagonal cracks: Professional evaluation required
Floor Cracks: Usually Not Structural
Basement Floor Cracks:
Extremely common
Usually not structural concern
Floor is not structural element (walls and footings are)
Can allow water/radon entry
When Floor Cracks Are Normal:
✓ Typical width (hairline to 1/8") ✓ Random pattern ✓ Not accompanied by heaving or displacement ✓ No water actively coming through
When to Address Floor Cracks:
⚠ Water enters through cracks ⚠ Floor heaving or displacement ⚠ Wide cracks (over 1/4") ⚠ Radon concerns
Action Plan:
Minimal, no water: No action needed
Water entry: Seal as part of waterproofing
Heaving/displacement: Professional evaluation (indicates soil pressure)
Sealing Cost: $200-500 typically included with waterproofing
Location Matters: Where Cracks Appear
Cracks at Top of Wall (Near Ceiling):
Often from house settling
Less concerning than mid-wall
Monitor for growth
Cracks at Mid-Wall (4-8 feet below grade):
Most concerning location
Maximum soil pressure zone
Especially serious if horizontal
Cracks at Bottom of Wall (Near Floor):
Can be from shrinkage or settlement
Monitor if widening
Common at cold joint (where wall meets footing)
Corner Cracks:
Stress concentrates at corners
Very common
Often from normal settlement
Monitor if widening or if multiple corners affected
Secondary Signs of Foundation Problems
Cracks don't exist in isolation. Look for these accompanying issues:
Doors and Windows:
Suddenly sticking or won't close
Gaps between door/frame
Windows won't open/close
Indicates foundation movement
Floors:
Sloping (marble rolls in one direction)
Bouncy or soft spots
Cracks in tile floors
Separation from walls
Walls:
Bowing or leaning
Gaps between walls and ceiling
Nail pops or drywall cracks above
Separating trim
Exterior:
Cracks in brick veneer (stair-step pattern)
Gaps at chimney
Separation of addition from main house
Cracks in garage floor
If You See Multiple Signs: Foundation movement is likely active and ongoing. Professional evaluation required.
Documentation: Your Best Tool
What to Document:
Photograph every crack:
Include ruler for scale
Take from multiple angles
Date all photos
Measure widths:
Use crack gauge or ruler
Measure at widest point
Record measurement and date
Mark crack ends:
Use pencil to mark where crack ends
Check if crack extends over time
Track changes quarterly:
Re-photograph with ruler
Compare to previous photos
Note any growth
Document water intrusion:
Photo after rains
Note if seasonal or always present
Why Documentation Matters:
Shows if cracks are stable or growing
Helps professionals diagnose issues
Valuable for insurance claims
Important for home sale disclosures
Tracks repair effectiveness
Pro Tip: Create a folder on your phone labeled "Foundation - [Address]" and set quarterly reminders to take photos.
When to Call a Professional
Call Immediately (Within Days):
Any horizontal crack
Bowing or leaning walls
Cracks wider than 1/4"
Rapidly growing cracks
Multiple new cracks appearing
Doors suddenly won't close
Active water intrusion
Schedule Evaluation Soon (Within Weeks):
Stair-step cracks over 1/8"
Multiple vertical cracks
Diagonal cracks from corners
Any crack that's growing
Secondary signs (sticking doors, etc.)
Monitor and Document:
Hairline vertical cracks (stable)
Single small corner crack
Floor cracks without displacement
Minor settling cracks in first 1-2 years
Types of Professionals
Home Inspector (HHI Services):
What: Comprehensive assessment, identify issues, recommend specialists
Value: Identifies problems, prioritizes concerns, connects you with right specialist
Structural Engineer:
When: Serious cracks, bowing walls, settlement issues
What: Structural analysis, load calculations, repair design
Cost: $500-1,500 for evaluation and report
Value: Expert diagnosis, engineer-stamped reports for permits
Foundation Specialist:
When: Ready to repair, need multiple quotes
What: Repair proposals, installation, warranty
Cost: Free evaluation (with hope of getting repair job)
Value: Repair options and costs, but may oversell
Best Approach:
Start with home inspector for objective assessment
Get structural engineer if serious concerns
Get 3+ foundation specialist quotes for repairs
Crack Repair Options
DIY Crack Sealing (Exterior):
Best For: Hairline vertical cracks, preventing water entry
Materials:
Hydraulic cement: $10-20
Polyurethane caulk: $8-15
Concrete crack filler: $15-30
Process:
Clean crack thoroughly
Apply filler according to directions
Smooth and finish
Allow to cure
Cost: $20-50 per crack Effectiveness: Good for water prevention, not structural
Professional Crack Injection:
Best For: Active leaks, wider cracks, permanent seal
Methods:
Epoxy injection (structural repair)
Polyurethane injection (water seal, flexible)
Cost: $400-800 per crack Warranty: Usually 5-10 years
Structural Repairs:
Options:
Carbon fiber straps
Steel I-beams
Wall anchors
Helical piers (underpinning)
Cost: $5,000-15,000+ depending on extent
Michigan-Specific Considerations
Freeze-Thaw Factors:
Cracks may open wider in winter (soil expansion)
May close slightly in summer
Seasonal variation is normal to a point
But overall growth year-over-year is concerning
Clay Soil Issues:
Common in SE Michigan
Expands when wet, shrinks when dry
Can create seasonal movement
Requires excellent drainage to minimize
When to Seal Cracks:
Spring/Summer: Best time for exterior sealing
Fall: Seal before winter to prevent freeze-thaw in crack
Winter: Emergency only (most products require 40°F+)
How HHI Services Can Help
Foundation Crack Assessment:
Identify all cracks and rate severity
Evaluate secondary indicators
Provide written assessment with photos - see sample report here
Recommend monitoring vs. repair
Connect with trusted structural engineers or foundation specialists
Pre-Purchase Inspections:
Comprehensive foundation evaluation
Identify existing cracks and issues
Assess repair needs and costs
Help negotiate repairs or credits
Pre-Listing Inspections:
Find and document cracks before buyers
Get professional assessment and quotes
Make informed decisions on repairs
Proper disclosure protects you legally
Key Takeaways
✓ Horizontal cracks = immediate professional evaluation
✓ Vertical cracks under 1/8" usually okay if stable
✓ Document all cracks with photos and measurements
✓ Growing cracks are more concerning than width
✓ Multiple signs together indicate active problems
✓ When in doubt, get professional evaluation
✓ Small investment in evaluation prevents big repair bills
Foundation Series Wrap-Up
You've now completed our comprehensive foundation protection series:
Part 1: Proper drainage and freeze-thaw prevention
Part 2: Waterproofing solutions for Michigan basements
Part 3:Understanding and assessing foundation cracks
The Foundation Protection Formula:
Maintain proper drainage (gutters, grading, downspouts)
Install and maintain waterproofing systems
Monitor foundation regularly for changes
Address small problems before they become big
Get professional help when needed
Annual Foundation Care Budget:
Preventive maintenance: $200-500
Monitoring/inspections: $0-600
Minor repairs as needed: $200-1,000
Total: $400-2,100/year
Cost of Neglect:
Major foundation repair: $5,000-30,000+
Structural failure: $20,000-50,000+
Decreased home value: 10-20% of home value
Prevention is always cheaper than repair.
Take Action Today
Foundation Crack Check (15 minutes):
Walk entire basement with flashlight
Photograph all cracks with ruler
Measure widest points
Note any water staining
Check for secondary signs
Create folder to track over time
If you find concerning cracks or want professional assessment:
📞 Call HHI Services: 248-388-4783
📧 Email: erikhodge@hhiservice.com
Schedule Your Buyer's or Seller's Inspection Today.
Knowledge is power, and early detection saves thousands.
Serving Southeast Michigan: Oakland County • Macomb County • Wayne County • Livingston County • Washtenaw County
Read the Complete Foundation Series:
Part 1: Foundation Protection: Michigan Freeze-Thaw Survival Guide
Part 2: Basement Waterproofing Solutions
Part 3: Reading Foundation Cracks (You Are Here)
Next Series Coming Soon: Winter Protection for Michigan Homes
Ice Dam Prevention
Frozen Pipe Protection
Winter Preparation Checklist