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This chapter of the "Foundation Crack Bible" discusses in detail the process of recognizing & evaluating vertical foundation cracks and foundation damage.

Foundation cracks and movement are discussed by type and location of foundation cracks, vertical foundation cracks, horizontal cracks, and diagonal foundation cracks, and shrinkage cracking.

Foundation cracks, which are signs of foundation damage, can mean very different things depending on the material from which a foundation is made, the location, size, and shape of the foundation crack, and other site observations. Also 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

© Copyright 2009 Daniel Friedman, All Rights Reserved. Information Accuracy & Bias Pledge is at below-left. Use links at the left of each page to navigate this document or to view other topics at this website. Green links show where you are in our document or website.

FOUNDATION CRACK EVALUATION - How to Inspect & Evaluate Building Foundation Cracks & Movement & Foundation Crack Patterns

This is a chapter of "The Foundation Crack Bible". Use links at page left to read other document sections.

VERTICAL FOUNDATION CRACKS - Vertical Foundation Crack Patterns

In the photos shown here, substantive cracks appeared and continued to increase in size in this poured concrete foundation used to support a modular home which had recently been completed. The cracks and foundation movement were probably due to a combination of: poorly prepared foundation footings, blasting on an adjacent building lot to prepare that site for new construction, and possibly omission of steel reinforcement in the poured wall.

The cracks in this building foundation wall were visible shortly after construction as vertical hairline openings (less than 1/16" wide) in the right hand foundation wall, above grade and inside in the basement. Within a year the owner reported several times that the cracks were becoming noticeably wider.

A careful inspection of the building interior suggested that the front foundation wall and portions of the right foundation wall were settling. There were no corresponding cracks in the finished surfaces of the structure, probably because this was very stiffly-framed modular construction. Notwithstanding the absence of damage upstairs, this was a problem that deserved further evaluation and repairs. The builder may have repaired the foundation by supporting it from below using one of the methods described at FOUNDATION REPAIR METHODS.

This settlement crack probably occurred during initial footing settlement. Notice that it is wider at the top than the bottom of the crack. This suggests that the footing to the left or right of the crack has moved downwards, with further downwards movement as we move further from the crack itself. If this is new construction and the crack does not change in width the site conditions may have stabilized.

How to Diagnose the significance of types of vertical cracks in foundations

• Vertical foundation cracks in masonry between two structures - differential settlement or thermal movement, often seen where an add-on garage is built on more shallow footings on backfill next to a full foundation.
• Vertical, nearly straight or wandering cracks in poured concrete, generally even width, intermittent, or more often straight - shrinkage / thermal - low risk
• Vertical cracks, straight generally even width, in a masonry block wall, in mortar joints but possibly right through concrete block - shrinkage / thermal - low to modest risk
• Vertical foundation cracks that are straight or stepped in brick, especially near ends of wall - expansion / thermal, potentially dangerous if wall bond courses are broken, collapse risk.
• Vertical cracks in a foundation wall, wider at bottom than top - settlement under building. These cracks may be less serious than horizontal when found in a masonry block wall. These cracks could be quite serious when found in a brick wall, especially if bond courses are broken and there is risk of collapse.
• Vertical cracks in a foundation wall, uniform in width, one side of crack/wall higher than the other: differential settlement in footings, possibly a serious defect; this crack may have the same cause as the tapered crack above but suggests that the footing has both broken and settled straight down at one side of the crack

Multiple vertical cracks in building foundations

Vertical foundation cracks often appear in multiples multiple cracks in one or more area.

While a vertical foundation crack could be serious depending on its cause and on the type of foundation in which it appears (stone, brick, masonry block, concrete), these are often the least threat to the building. If there is significant vertical dislocation or signs of ongoing movement, further investigation is more urgent. If the cause is shrinkage (concrete, masonry block) it is probably less of a concern than if due to settlement. A vertical crack due to earth loading or frost would be unusual.

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FOUNDATION DIAGNOSIS
INTRODUCTION
FOUNDATION INSPECTION METHODS
SITE FACTORS AFFECTING FOUNDATIONS
FOUNDATION CONSTRUCTION TYPES
FAILURES by FOUNDATION TYPE & MATERIAL
FOUNDATION DEFECTS OF OMISSION
FOUNDATION CRACK EVALUATION
  VERTICAL FOUNDATION CRACKS
  CRACK MONITORING Methods
  DIAGONAL FOUNDATION CRACKS
  HORIZONTAL FOUNDATION CRACKS
  SHRINKAGE vs EXPANSION vs SETTLEMENT
  Sinkholes & Building Damage
SLAB CRACK EVALUATION
FAILURES by FOUNDATION MOVEMENT TYPE
FOUNDATION BULGE or LEAN MEASUREMENTS
FOUNDATION MOVEMENT ACTIVE vs. STATIC
FOUNDATION DAMAGE SEVERITY
FOUNDATION DAMAGE REPORTS
FOUNDATION REPAIR METHODS
ADDITIONAL READING
FOUNDATION INSPECTION STANDARDS

• 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
• 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

Technical Edits, Changes, Amendments to This Document

• 9/23/2006 editing to clarify text and add content; Technical review (partial) by Arlene Puentes.
• 4/17/2006 editing to clarify text in several sections.
• 2/6/99 editing updates, soliciting additional reviews
• 2/3/99 Converted working text file to MSWord97 .doc and .htm files for easier review on Internet
• 6/26/95 text updates per comments from Al Carson, Terry Carson, Mark Cramer 6/16/95 text updates for Calgary July 1995
• cc's sent to reviewers
• 3/28/95 uploaded to ASHI's Internet site - asfoun01.txt
• 11/19/93 Ed Seaquist - telecon 11/19/93, likes, will write up one of our sections for my/our target of series of journal articles or a book.
• © Dan Friedman 1999, original 1992 All Rights Reserved -- foundation.htm

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