How to Evaluate the Significance or Amount of Foundation Movement when a foundation is leaning, bulging, bowing, or settling.

This document 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.

Types of foundation cracks, crack patterns, differences in the meaning of cracks in different foundation materials, site conditions, building history, and other evidence of building movement and damage are described to assist in recognizing foundation defects and to help the inspector separate cosmetic or low-risk conditions from those likely to be important and potentially costly to repair.

Foundation DAMAGE SEVERITY - How to Evaluate the Significance or Amount of Foundation Movement when a foundation is leaning, bulging, bowing, or settling

The photo above shows a cracked, bulged, leaning stone foundation wall at the edge of an embankment - a condition we discuss further at this website.

Historical data is a key observation or data that needs to be collected to assess the significance of any evidence of foundation movement

• New or sudden foundation movement:
  
  If foundation cracking or movement is new, recent, or sudden: serious, prompt action is needed and you should consult an expert, in particular if the amount is more than trivial.
  
  Trivial movement would be the discovery of a hairline crack (less than 1/16" in width) or a shrinkage crack in a building foundation wall or floor slab.
  
  A word of caution: sometimes a crack has been present for a long time at a building but has simply not been noticed by the building owner or occupants.
  
  The first time such a crack is seen it may be mistaken for "new" and "sudden" when that's not the case. See our discussion
  
  of SHRINKAGE vs EXPANSION vs SETTLEMENT for some examples.
• Recurrent foundation cracking or movement:
  
  action is probably needed since recurrent movement can lead to cumulative damage to some structures even if the amount of movement is not great.
  
  In particular, if you have made cosmetic repairs to a foundation or to plaster or drywall finished areas above and supported by such a foundation you may see that the cracks you repaired have simply recurred.
• Long term, continuing, but slow 
  
  foundation movement: action may be needed, particularly if the effects of long term foundation movement are cumulative.
• Initial foundation cracking
  
  or other limited damage occurring at time of construction such as foundation cracks in a masonry block wall which occurred during backfill may not need other than cosmetic repairs,
  
  in particular if there is no evidence of subsequent foundation movement and still more likely if the initial damage and amount of movement was minor (say less than 1/2" of inwards foundation wall bulge in the cracked areas.)
• Foundation damage due to being struck:
  
  in this case the foundation will certainly need repair if the damage to it was extensive with collapsed or severely dislocated components. Trivial foundation damage, say cracking a masonry block on the corner of a garage with no basement below, is less likely to be significant.
• Initial foundation settlement may not require additional repair.
  
   A hairline to 1/16" vertical crack in a concrete wall or similar dimension step cracking in a masonry block wall may need cosmetic and sealant repair (to reduce leakage through the wall, but if the initial amount of settlement was very small and is not ongoing, repair is unlikely to be needed.

These examples of foundation damage are almost always very important and need expert attention

• Dislocated gas, plumbing, or electrical wiring or piping:
  
  NOTE: ANY foundation damage or crack associated with significant displacement of original structural or mechanical (gas/sewer lines) components is likely to be significant. Even slight displacement is significant if mechanical systems may be unsafe (earthquake).
  
  Watch out: Dislocated gas lines means gas leaks are likely and there is serious damage of catastrophic explosion. Vacate the property, and immediately call the gas company from a telephone that is not exposed to gas fumes.
• Dislocated or broken structural connections 
  
  such as a building which has shifted off of its foundation or has broken sill bolts or straps connecting the foundation to the building framing needs expert investigation and repair.
  
  Watch out: broken structural connections, particularly supporting floors or roofs, risk a catastrophic structural collapse.
• Bulging foundation walls
  
  in response to area flooding, earthquake, or other forces are at risk of collapse;
  
  temporary support of the building and other measures to relieve stress on the foundation may be needed. Do not delay in seeking expert advice in this situation.
• Watch out: Bulging brick structural or veneer walls 
  
  are very serious as the breakage of bond courses - which allows bulging - can indicate imminent or sudden and catastrophic structural collapse.

This list is not complete. Suggestions welcomed.

Some simple "rule of thumb" for evaluating the seriousness of foundation damage

Amount, type, & direction of foundation movement

• Bulging brick 
  
  if broken bond courses, as we said above this is very serious/dangerous
  
  (1/3 "rule" without breakage -A. Carson; author opinion: this needs clarification. 1/3 of wall thickness looks like much too much movement to allow--DF.)
• Bulging masonry block
  
  risk of collapse or sudden collapse, particularly if additional force such as water, melting snow, or vehicular traffic are applied
• Diagonal cracks 
  
  usually indicate footing settlement or frost heave or frost lensing and in extreme cases may risk wall collapse.
• Leaning foundation walls
  
  may risk collapse if the amount of lean is significant (amounts are discussed in this and companion articles) or if movment has separated structural connections, with greater risk if additional force is applied just as cited above.
• Vertical & horizontal dislocation in the foundation wall
  
  depends on amount.
• Horizontal cracks
  
   in a masonry unit (block or brick) present a higher risk of collapse than vertical cracks in the same walls, depending on the amount of disclocation.
• Vertical cracks
  
  usually indicate footing settlement and may also need repair but usually present less risk of sudden catastrophic collapse unless the amount and nature of movement have separated structural connectors or supports such as posts or column footings.

The importance of the amount of foundation movement varies

These additional conditions change the importance of the amount of foundation movement

• Wall height
• Wall type of construction
• Wall construction materials
• Implications for building: structure-pulled framing apart?
• Site factors which increase risk: earth loading, such as from water, mud, snow, ice, frost, vehicle traffic

Climate, seismic, & other local foundation structural requirements

• Earthquake design requirements for reinforcement
• Cold-climate design requirements for reinforcement, drainage, frost protection
• Storm/High-wind (and earthquake) design requirements for connections to framing (not considered here)

Expert Views regarding Evaluating Foundation Crack Size / Width or Extent of Foundation Movement

British Royal Institute of Chartered Surveyors, RICS - Degree of Damage - per W.H. Ransom (RICS)

• Very slight/slight single, isolated cracks -
  
  Fine cracks, <5mm (.3") wide, slight sticking windows/doors
• Moderate - 5-15mm (.2"-.6") wide,
  
  point up brick, some local replacement, doors/windows stick, pipes may break, not weather tight
• Severe/very severe - > 15mm (.6") to > 25mm (1"),
  
  walls likely to lean, bulge, may require shoring; beams may lose bearing; windows distort, glass may break, pipes probably break. External repairs needed, partial or complete rebuild.
• Multiple small cracks,
  
  leaning, shifting can be serious too.

Foundation Damage Severity Terms Characterize Foundation Damage

Based on multiple national ASHI seminar polls conducted by the author - American Society of Home Inspectors (ASHI)

Minor, single, isolated, cosmetic, marketing concerns

• Cracks, hairline to 1/16" horizontal
• Cracks, hairline to 1/8" vertical and step; [1/4" ? per Alk - note that this is an unsubstantiated opinion]]
• Cracks in slabs, hairline to 1/8", not extending into foundation and with no significant vertical dislocation or settlement

Modest foundation damage, monitoring appropriate

• Horizontal bulge < 1.5",
  
  no signs of other significant damage
• Leaning wall < 1/3 of wall thickness,
  
  from wall base (In author's opinion 1/3 is way too much movement to tolerate; a conventional thickness masonry block wall that leans in one inch over an 8' ht. (or maybe 1.5" per some surveys) might be monitored depending on other site conditions, history, etc.
  
  Walls buckled in or leaning more than 1" (or 1.5" in some jurisdictions) should be professionally evaluated further and may require near-term or even immediate repair; Walls buckled in or leaning an inch or less should be monitored.
• If the cracks are old, with no sign of continuing/recurrent movement -
  
  the inspector is more likely to accept monitoring rather than requiring repair.
• Cracks described by "wavy mortar"
  
  which were caused by damage during backfill while mortar was still "green" or soft (un-cured) and which are not accompanied by other signs of ongoing or additional movement, can be attributed to a single-event and may not require repair (depending on total amount of wall dislocation).

Significant, expert foundation assessment needed. Foundation repair may be needed

• >1.5" horizontal bulge/lean
• > 1/4" Lateral dislocation
• Signs of active, recent, recurrent movement (may be seasonal or ongoing)
• Sudden appearance of cracks, particularly in areas known to have sink-holes (e.g. some areas of the U.S. such as in Florida.) requires immediate assessment.
• Signs of repeated repairs to foundation or interior
• Cracks 1/4" [ 3/8" per Alk] & larger
• Uncertainty? Investigate further any finding of which the inspector is uncertain or inexperienced.

Watch out: Don't make conclusions just based on crack size and location. The inspector must consider other site factors conditions, history, materials, external forces, etc. Sudden catastrophes CAN occur, especially where site drainage or other conditions risk undermining or sudden forces on the foundation.

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Reader Q&A - also see RECOMMENDED ARTICLES & FAQs

On 2019-10-1 - by (mod) -

Richard I want to help but don't dare with not a shred of information about your home, the type of construction, the cause, location, pattern, extent of cracking, how far in the wall leans, how much impact has occurred to the structure, what's the risk of continued movement.

We need to know whether the wall can be reinforced (pilasters, stitchers, steel or masonry), or needs to be reconstructed.

Watch out: a bulged horizontally-cracked wall such as made of concrete block or brick, depending on how far it's moved, risks sudden structural collapse- someone could be hurt or worse.

You need an onsite expert to tell you the condition of the wall, the cause of damage; then one can discuss the best repairs needed.

On 2019-10-13 by Richard Weitz

I have a major horizontal crack in my basement foundation wall. What would you recommend to repair the wall
Thank you, Richard

On 2018-12-31 - by (mod) - vertical crack in a concrete block foundation wall that is wider at the top than at the bottom

I see a vertical crack in a concrete block foundation wall that is wider at the top than at the bottom but appears to extend over a whole height of the wall. It makes me suspect that there is footing settlement going on and that such settlement may continue.

I wouldn't expect there to be a sudden catastrophic collapse but the damage May indeed continue. Keeping water away from the foundation may slow the process.

They're on site investigation of all of the foundation and structure would put this particular piece of damaged in context and help decide on priority of action. In other words without that I don't know how urgent this problem is but I suspect it's not an emergency.

Remember that no one can accurately nor completely assess Foundation damage by a brief a text and let some photos. A great deal of additional site information that needs to be considered.

On 2018-12-31 by Theresa

I am wondering if these photos show any cause for concern. There are numerous other structural issues with this property, but I have noticed that these cracks have grown in less than 2 years. Built in 2009, photos are of 2nd and 3rd floor stairwell. Thanks!
IMAGE LOST by older version of Clark Van Oyen’s Comments Box code - now fixed. Please re-post the image if you can. Sorry. Mod.

On 2018-12-17 - by (mod) -

babu_narsim

Unfortunately I cannot be as smart or informed as an expert who could come to inspect the temple and site directly - that is what is needed.

However from just your photographs - taken from your video of the temple, it appears to me as if there are several types of damage:

1. settlement - moving down of supporting soil from drying out of the clay soil as you suggested, that can explain walls leaning out of level or that have moved downwards in some spots.

Sometimes an engineer will decide that it is possible to pump concrete under high pressure to lift such structures but in your case I doubt that that is a useful solution for several reasons including - correct me if I'm mistaken - the following:

1. no one nearby has that pumping technology
2. the structure is so damaged that simply pushing it up won't fix that damage and risks further cracking and even collapse

2. Some of the damage such as the vertical cracks in pillars appear to me to be breaks from failure of the original columns due to weight or loading from above. I suspect that the original structure was built of cement and stone without any interior reinforcement.

I would expect repairs to those columns to require making temporary support - heavy vertical beams that themselves are placed on heavy horizontal members to distribute the weight - to hold the upper structure while the column is disassembled and re-built in place.

At that time you may need to dig down sufficiently to prepare a supporting concrete pad or footing for each column to prevent further settlement.

Please also see

EXPANSIVE CLAY SOIL DAMAGE to FOUNDATIONS

at https://inspectapedia.com/Energy/Expansive_Clay_Soil_Foundation_Damage.php

On 2018-12-17 - by (mod) -

IMAGE LOST by older version of Clark Van Oyen’s Comments Box code - now fixed. Please re-post the image if you can. Sorry. Mod.

On 2018-12-17 - by (mod) -

Additional image
IMAGE LOST by older version of Clark Van Oyen’s Comments Box code - now fixed. Please re-post the image if you can. Sorry. Mod.

On 2018-12-17 - by (mod) -

Re-posting without disallowed video link (for site security)

babu_narsim@yahoo.com said:
greetings
i am very happy to see the discussion points related to a heritage 230 year old temple at our place.A small riverlet flowing nearby was stopped leading to the clay or aluvial soil adjoining the temple becoming dry and the the structure had fractured.

Now, we are renovating the structure without comprising the heritage archaelogical designs. unfortunately not able to get the right way to reclaim the distorted portion of the structure. Can you suggest way and means to bring back the distorted settled structure to its original level. Your inputs will greatly help the community to revive back their heritage.

From the link given by Mr. Narsim:

IMAGE LOST by older version of Clark Van Oyen’s Comments Box code - now fixed. Please re-post the image if you can. Sorry. Mod.

...

Continue reading at FOUNDATION REPAIR METHODS or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.

Or see FOUNDATION DAMAGE SEVERITY FAQs - questions and answers posted originally on this page.

Or see these

Recommended Articles

• BULGED vs. LEANING FOUNDATIONS
• BULGE or LEAN MEASUREMENTS
• FOUNDATION CRACK DICTIONARY for a discussion of the diagnosis of specific crack patterns in masonry
• FOUNDATION DAMAGE & REPAIR GUIDE - home
• FOUNDATION DAMAGE REPORTS
• FOUNDATION DAMAGE by ICE LENSING
• FOUNDATION DAMAGE by MATERIAL or INCLUSIONS
• FOUNDATION DAMAGE SEVERITY
• FOUNDATION FAILURES in CLAY SOIL
• FOUNDATION FAILURE by INSULATION - insulation causing foundation buckling or damage
• FOUNDATION FAILURES by MOVEMENT TYPE - home
• FOUNDATION FAILURES by TYPE & MATERIAL - home
• FOUNDATION INSPECTION METHODS
• FROST HEAVES, FOUNDATION, SLAB
• HORIZONTAL MOVEMENT IN FOUNDATIONS
• STONE FOUNDATION DEFECTS
• STRUCTURAL COLLAPSE HAZARDS
• VERTICAL MOVEMENT IN FOUNDATIONS

Suggested citation for this web page

FOUNDATION DAMAGE SEVERITY at InspectApedia.com - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.

Or see this

INDEX to RELATED ARTICLES: ARTICLE INDEX to BUILDING STRUCTURES

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