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How to Detect, Diagnose, & Evaluate Horizontal Foundation Movement, Cracks, Damage StructAPedia © Enter your search terms Submit search form   Search This Website - InspectAPedia.com

• How to Evaluate and Diagnose Horizontal Foundation Movement by Type & Location of Cracks, Bends, Leans, or Shift in Foundation Walls
• How to recognize foundation impact damage
• How to recognize foundation creep or footing movement

This chapter of the "Foundation Crack Bible" discusses in detail How to Evaluate and Diagnose Horizontal Foundation Movement by Type & Location of Cracks or Shift in Foundation Walls. Horizontal foundation wall movement may be caused by earth pressure, vehicles driving too close to a building wall, water and frost, and even footing movement or foundation wall creep on hillsides.

We distinguish among vertical movement, horizontal movement, leaning, tipping, bending, differential and uniform settlement, earthquake and storm damage, and other foundation damage patterns. Our "Foundation Crack Bible" document, of which this web page is a chapter, describes how to recognize and diagnose various types of foundation failure or damage, such as foundation cracks, masonry foundation crack patterns, and moving, leaning, bulging, or bowing building foundation walls.

Also see FOUNDATION CRACK EVALUATION for a discussion of the diagnosis of specific crack patterns in masonry foundations, and see FOUNDATION BULGE or LEAN MEASUREMENTS which explains a simple method for determining how much bulge or lean is present in a foundation or wall, then see FOUNDATION MOVEMENT ACTIVE vs. STATIC which helps determine if the foundation movement is ongoing, and see FOUNDATION DAMAGE SEVERITY for a discussion of just how much foundation movement is likely to be a concern.

To be used properly, this information must be combined with specific on-site observations at the particular building in order to form a reliable opinion about the condition of that building's foundation. Anyone having concern regarding the structural stability, safety, or damage of a building, foundation or other components, should consult a qualified expert. Photographs of types of foundation cracks and other foundation damage: we have a large library of photographs which we're in process of adding to this document. Pending completion of that work, contact the author if assistance is required.

Horizontal Movement in Foundations & Masonry Building Walls

Horizontal foundation wall movement includes leaning, tipping, or bulging foundation walls as well as movement of an entire wall in a single direction such as hillside slippage or creep. Knowing just how a foundation wall is moving and just what is causing damage are important in deciding on how to repair the damaged foundation wall and how to prevent further foundation movement. Typical causes of horizontal foundation movement include:

• Frost pressure (in freezing climates)
• Soil pressure (depending on the amount of backfill & soil characteristics)
• Soil pressure + water pressure caused by extra weight from water (rain, surface runoff, or flood conditions)
• Soil pressure + live loading caused by extra weight from vehicles driven near the foundation wall
• Impact pressure caused by a vehicle or a storm-driven object like a tree
• Earthquake/Storm movement: Horizontal shift during earthquake or storm damage

How Soil Pressure vs. Frost & Water Pressure Cause Different Damage to a Foundation Wall

Two Cases Where Frost Heave is Unlikely - Foundations on Bedrock & Well-drained Soils

How Lateral or Horizontal Foundation Pressure Shows Up as Damage

Horizontal movement in building foundations or walls is generally caused by an external lateral or "sideways" force applied to some portion of the wall. Depending on the construction materials used and the strength of a foundation wall, a force applied to the wall can cause it to move in any of several ways:

• Bulging foundation wall movement: the wall may bend or "bulge", tending to bulge away from the force (usually inwards into the building from earth, water, or frost pressure), with the greatest amount of inwards movement at or near the point of greatest pressure or force being applied.
  
  If the wall is constructed of concrete block, for example, it may bulge inwards and crack or break horizontally along its mortar joints high on the wall if the damage is due to pressure from a heavy vehicle driving close to the wall, or it may crack in the top 1/3 of the wall if the damage is due to pressure from frost. As you can see in our soil pressure sketch above on this page, a break lower in a foundation wall (assuming it is buried to near the wall top) suggests earth pressure or wet earth pressure more than frost pressure problems.
  
  Heavy or heavy and wet soils may also produce inwards movement and crackng lower on a wall when pressure is primarily due to earth pressure rather than frost. Of course the height of such bending or cracking depends on the height of the entire wall, how much of the wall is below ground level, and where the force is being applied.
• Leaning foundation wall movement: the wall may lean away from the force being applied (usually into the building from the same forces listed above). A reinforced concrete wall or a vertically-reinforced concrete block wall may tend to lean rather than break in response to the same forces we've listed. When force is closer to the top of such a wall, the top will lean inwards. When the forces are closer to or greatest at the bottom of the wall, the bottom may tend to lean inwards and the top of the wall lean "outwards".
• Shifting or creeping foundation wall movement: a foundation wall, or portions of it, may remain close to vertical, without leaning or bulging, but forces applied to the wall may cause the entire wall (or a portin of it) to move horizontally.
  
  We see horizontal shift or creep occuring in several cases: The wall may be sliding off of its footing, or an entire footing and wall may be sliding downhill over rock or clay soils; in this case vertical cracks may appear where the moving wall is or was joined to its neighboring side walls. Forces applied to a wall may cause a portion of it to break and slide horizontally over another portion.
  
  For example a masonry wall may become pushed inwards from soil or frost, but where the first course of blocks is held in place by a concrete floor slab, that course may remain un-moving. Depending on where the wall breaks from outside forces, upper courses of the masonry block wall will slide horizontally over and "hang over" the lower course(s) of block.
• Complex foundation wall movement: most of the drawings we see at seminars on foundation damage or used by companies offering foundation repair products are clear and helpful for understanding the concept of foundation damage and movement, but often they do not describe what we actually find in the field. Very often the forces that are causing a building foundation to move will cause a combination of bulging, cracking, leaning, and shifting of foundation or wall components.

We illustrate horizontal foundation wall movement patterns below.

Bulging or Leaning and Sliding Horizontal Wall Movement - Masonry Block "Overhang"

Inspectors or building owners may also encounter a foundation wall which has moved inwards in a combination of forms, both bulging at its most-pushed-in point (with horizontal cracks in the foundation wall) and the wall may have also been pushed inwards sliding some of the masonry blocks inwards past others which have remained in place. In this case you'll see both that some masonry wall blocks will overhang or protrude past others in the wall (usually upper inwards pushed blocks hang over lower more stable blocks closer to the floor), and there may be bulging and cracking at another elevation of the wall. This is a photograph of frost push and horizontal overhang or sliding between horizontal courses of a masonry block wall.

Impact Damage to Foundation Walls - horizontal movement

Impact damage from a vehicle or from unusual weather such as a hurricane which lifts and tosses large objects, can lead to severe foundation or masonry wall damage and may even render the wall unstable and unsafe. In the photograph shown here the cause of damage to the foundation wall is pretty obvious. Almost certainly a delivery truck has backed into this concrete block wall, perhaps even more than once. The damage to this wall was extensive, extending nearly to the top of the structure. The wall needs extensive repairs, probably reconstruction.

Horizontal Foundation Wall Movement, Creep, non-leaning Lateral Shift

On less frequent occasions we've found that an entire masonry block wall (or portions of it) were pushed horizontally inwards by some outside force, without causing the wall to lean or bulge. In the photograph here we suspect that the cracks in this masonry block wall occurred as a defective wall footing began to creep down a steep hill behind the building. In a pure example of horizontal creep or movement without leaning in a masonry wall or foundation, all of the differential movement measured (wall to string) between the wall bottom point (held in place by the floor slab) and the inwards-pushed wall section, will be a horizontal movement of that portion of the wall, and if it's masonry block, you'll see that the inwards-moved blocks are "hanging over" or projecting past the surface of the masonry blocks that did not move. Other vertical or near vertical cracks in concrete block can occur in foundation wall without leaning or bulging if the entire wall is moving due to footing settlement or frost or, as we showed here, possible tipping or leaning of the footing itself. If the bottom of a wall is not pinned in place by a secure footing or a concrete slab, or if the entire footing itself begins to move, the entire wall, from top to bottom may move horizontally with no leaning and with no "overhang" of one portion of the wall over another. In this case we'd expect to see cracking or evidence of separation of this section of wall from its neighboring sides - as you can see in the upper vertical cracking at the left side of the masonry block wall in the photograph above.

Horizontal wall movement and step cracking in brick walls due to thermal expansion

Horizontal movement occurs in brick masonry walls due to thermal expansion, producing step cracking and potentially also verticl cracks through structural brick or brick veneer walls. If you are considering a brick masonry building, or a building carrying a brick veneer exterior, we discuss and illustrate thermal cracking in brick masonry in detail at Thermal Expansion Cracking of Brick Also see See SHRINKAGE vs EXPANSION vs SETTLEMENT for aid in distinguishing between these different conditions.

FOUNDATION DIAGNOSIS
EARTHQUAKE DAMAGED FOUNDATIONS
FOUNDATION CONSTRUCTION TYPES
FOUNDATION INSPECTION METHODS
FAILURES by FOUNDATION TYPE & MATERIAL
  Block Foundation & Wall Defects
  Brick Foundation & Wall Defects
  Brick Thermal Expansion Cracking
  Concrete Poured Foundation Wall & Slab Defects
  Concrete Pre-cast Foundation Defects
  Stone Foundation Defects
  Wood Foundation Defects
FAILURES by FOUNDATION MOVEMENT TYPE
  BULGED vs. LEANING FOUNDATIONS
  COMBINATIONS OF FOUNDATION MOVEMENT
    Bulge & step cracks
    Earthquake Damage to Foundations
    Flood Damage to Foundations
    Foundation Movement During Collapse
    Other Foundation Step cracks
  HORIZONTAL MOVEMENT IN FOUNDATIONS
    Bulging, Leaning & Sliding Wall
    Horizontal Foundation Creep
    Horizontal Movement & step cracks in brick
    Impact Damage to Foundations
    Thermal Expansion Cracking in Brick
  VERTICAL MOVEMENT IN FOUNDATIONS
    Diagonal Cracks in Concrete Foundations
    Diagonal Step Cracking in Masonry
    Differential vs. Uniform Settlement Cracks
    Leaning or Tipping Buildings
    Uniform Width vs. Tapered Foundation Cracks
    Vertical Cracks
FLOOD DAMAGE TO FOUNDATIONS
FOUNDATION DEFECTS OF OMISSION
FOUNDATION CRACK EVALUATION
  DIAGONAL FOUNDATION CRACKS
  HORIZONTAL FOUNDATION CRACKS
  SHRINKAGE vs EXPANSION vs SETTLEMENT
  Sinkholes & Building Damage
  VERTICAL FOUNDATION CRACKS
FOUNDATION BULGE or LEAN MEASUREMENTS
FOUNDATION DAMAGE SEVERITY
FOUNDATION DAMAGE REPORTS
FOUNDATION INSPECTION STANDARDS
FOUNDATION MOVEMENT ACTIVE vs. STATIC
FOUNDATION REPAIR METHODS
  Bulged foundation Repairs
  Crack Repair Methods
  Horizontal Movement Repairs
  Shrinkage Crack Repairs
  Vertical Movement Repairs
SITE FACTORS AFFECTING FOUNDATIONS
SLAB CRACK EVALUATION
  Control Joint Cracks in Concrete
  Freezing & Water Damage
  Frost Heave/Expansive Soil Cracks in Slabs
  Seal Cracks by Polyurethane Foam Injection
  Seal Cracks in Concrete, How To
  Settlement Cracks in Slabs
  Settlement Cracks vs. Frost Heaves
  Settlement Cracks vs. Shrinkage Cracks
  Shrinkage Cracks in Slabs
  Shrinkage Cracks Along Foundation Walls
  Standards for Repair of Cracks in Floors
WATER ENTRY in BUILDINGS
  SUMP PUMPS GUIDE
ADDITIONAL READING
More Information

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FOUNDATION DIAGNOSIS Chapter Index

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FOUNDATION DIAGNOSIS - how to inspect and diagnose foundation problems, in-depth diagnosis, and evaluation of all types of structural and non-structural cracks in residential foundations [Brick, Concrete, Masonry Block, Stone]
EARTHQUAKE DAMAGED FOUNDATIONS - examples of earthquake-damaged building foundations
FOUNDATION CONSTRUCTION TYPES - identify different foundation types, construction materials, effects of sequence of construction
FOUNDATION INSPECTION METHODS - what to look for when inspecting any building foundation
FAILURES by FOUNDATION TYPE & MATERIAL- unique failure characteristics of each foundation material
  Block Foundation & Wall Defects
  Brick Foundation & Wall Defects
  Brick Thermal Expansion Cracking
  Concrete Poured Foundation Wall & Slab Defects
  Concrete Pre-cast Foundation Defects
  Stone Foundation Defects
  Wood Foundation Defects
FAILURES by FOUNDATION MOVEMENT TYPE -recognize & diagnose types of foundation damage by the nature of foundation movement
  BULGED vs. LEANING FOUNDATIONS - distinction of foundation bulging from foundation leaning has important implications for stability
  COMBINATIONS OF FOUNDATION MOVEMENT - the real world of foundation cracks and movement: often more than one force is at work
    Bulge & step cracks
    Earthquake Damage to Foundations
    Flood Damage to Foundations
    Foundation Movement During Collapse
    Other Foundation Step cracks
  HORIZONTAL MOVEMENT IN FOUNDATIONS - detection, causes, effects, evaluation of horizontal or lateral foundation movement; hillsides
    Bulging, Leaning & Sliding Wall
    Horizontal Foundation Creep
    Horizontal Movement & step cracks in brick
    Impact Damage to Foundations
    Thermal Expansion Cracking in Brick
  VERTICAL MOVEMENT IN FOUNDATIONS - detection, causes, effects, evaluation of vertical foundation movement, differential settlement
    Diagonal Cracks in Concrete Foundations
    Diagonal Step Cracking in Masonry
    Differential vs. Uniform Settlement Cracks
    Leaning or Tipping Buildings
    Uniform Width vs. Tapered Foundation Cracks
    Vertical Cracks
FLOOD DAMAGE TO FOUNDATIONS - examples of flood damaged foundations, flood damage case analysis: were these cracks due to flooding?
FOUNDATION DEFECTS OF OMISSION - recognize things that were left out, like footings, reinforcement, soil compaction, during foundation construction
FOUNDATION CRACK EVALUATION- recognize & diagnose types of foundation cracks, movement, damage, by the size, shape, location, pattern of cracks
  DIAGONAL FOUNDATION CRACKS - causes and significance of diagonal foundation cracks, varies by foundation type & material
  HORIZONTAL FOUNDATION CRACKS - causes and significance of horizontal foundation cracks, varies by foundation type & material
  SHRINKAGE vs EXPANSION vs SETTLEMENT - which foundation materials shrink, which expand, & their characteristic crack patterns
  Sinkholes & Building Damage - sinkhole recognition, significance, cause, underlying geology, areas where sinkholes are worst
  VERTICAL FOUNDATION CRACKS - - causes and significance of vertical foundation cracks, varies by foundation type & material
FOUNDATION BULGE or LEAN MEASUREMENTS - procedure for documenting the amount of lean or bulge in a foundation or other building wall
FOUNDATION DAMAGE SEVERITY - rules of thumb for deciding how much foundation movement requires further action
FOUNDATION DAMAGE REPORTS - how to report foundation inspection results and damage
FOUNDATION INSPECTION STANDARDS - definition of scope of what a foundation inspector
FOUNDATION MOVEMENT ACTIVE vs. STATIC - determine if foundation movement was a one-time event or an ongoing problem
FOUNDATION REPAIR METHODS - catalog of methods used to repair damaged foundations and masonry building walls
  Bulged foundation Repairs
  Crack Repair Methods
  Horizontal Movement Repairs
  Shrinkage Crack Repairs
  Vertical Movement Repairs
SITE FACTORS AFFECTING FOUNDATIONS - drainage, rock, soil compaction, slope or grading, bedrock, sloping bedrock, proximity to roads
SLAB CRACK EVALUATION - recognize and diagnose different types of slab or concrete floor cracks and movement
  Control Joint Cracks in Concrete - what are control joints, why they are needed, what happens when they're omitted; are they structural?
  Freezing & Water Damage - recognize frost and water damage to concrete slabs, distinguish from other crack types
  Frost Heave/Expansive Soil Cracks in Slabs - distinguish between frost damage and expansive clay soil damage to slabs
  Seal Cracks by Polyurethane Foam Injection - stop basement or crawl space leakage
  Seal Cracks in Concrete, How To - products and methods used to seal or repair cracks in poured concrete walls, foundations, floors, & slabs.
  Settlement Cracks in Slabs - recognize slab settlement, assess risk, assess potential impact on structure
  Settlement Cracks vs. Frost Heaves - how to tell the difference between frost heaves and foundation settlement; does it matter?
  Settlement Cracks vs. Shrinkage Cracks - critical identification of shrinkage cracks (non-structural) compared with foundation movement
  Shrinkage Cracks in Slabs - causes, prevention, assessment of concrete slab shrinkage cracks
  Shrinkage Cracks Along Foundation Walls - why do we see a gap between a poured concrete slab and its abutting foundation wall?
  Standards for Repair of Cracks in Floors - when does a floor or slab crack need to be repaired? why?
WATER ENTRY in BUILDINGS
  SUMP PUMPS GUIDE - how a sump pump can avoid foundation damage and reduce building water entry
ADDITIONAL READING
More Information

Technical Content Reviewersfor Foundation Crack and Movement Damage Evaluation, Diagnosis, & Reporting

• Daniel Friedman - ASHI (1986-2006) - author of this website and article, building failures researcher.
• Sal Alfano - Editor, Journal of Light Construction*
• Thanks to Alan Carson, Carson Dunlop, Associates, Toronto, for technical critique and some of the foundation inspection photographs cited in these articles.
• Thanks to Alan Carson and Bob Dunlop, Carson Dunlop, Associates, Toronto, for permission to use illustrations from their publication, The Illustrated Home which illustrates construction details and building components. Carson Dunlop provides home inspection education, publications, report writing materials, and home inspection services. Alan Carson is a past president of ASHI, the American Society of Home Inspectors.
• Terry Carson - ASHI
• Mark Cramer - ASHI
• JD Grewell, ASHI
• Duncan Hannay - ASHI, P.E. *
• Bob Klewitz, M.S.C.E., P.E. - ASHI
• Ken Kruger, P.E., AIA - ASHI
• Bob Peterson, Magnum Piering - 800-771-7437 - FL*
• Arlene Puentes, ASHI, October Home Inspections - (845) 216-7833 - Kingston NY
• Greg Robi, Magnum Piering - 800-822-7437 - National*
• Dave Rathbun, P.E. - Geotech Engineering - 904-622-2424 FL*
• Ed Seaquist, P.E., SIE Assoc. - 301-269-1450 - National
• Dave Wickersheimer, P.E. R.A. - IL*
• *These reviewers have not returned comment 6/95

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