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• How to Perform Visual Diagnostic Inspection of a Foundation Wall or Slab
• Types of foundation damage
• Extent of foundation damage
• Photographs of foundation crack patterns

This document provides inspection methods useful in recognition & diagnosis of 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. © 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 INSPECTION METHODS
StructAPedia ^©

The general procedural steps and major topics in a foundation inspection include these steps. Links to discussions of each of these topics are at the left side of this page.

The photo at the top of this page shows a badly-cracked masonry block foundation wall with severe bulging and dislocation - this wall needs to be rebuilt and the cause of this movement corrected before the wall collapses. At this website we explain how it is sometimes possible to be confident about the cause of foundation damage which in turn helps assess the risk presented to the building. Contact us if you have questions, suggestions, or content contributions for this material. We are pleased to give full citation credit for technical reviewers and content contributions.

Below we list the broad categories of topics that a foundation inspector may need to consider when inspecting and evaluating the condition of a building foundation.

1. Site Factors: Observe site factors affecting the structure such as slope, drainage, rock, or nearby activities such as blasting. See SITE FACTORS AFFECTING FOUNDATIONS.
2. Construction: Identify construction type, materials, sequence of construction - the history of the site, the foundation, and its construction details. See FOUNDATION CONSTRUCTION TYPES.
3. Defects of Occurrence: Observe defects of occurrence - things that have happened to the structure such as signs of movement, history, other clues. A foundation crack, foundation movement, foundation lean or foundation bulge, or foundation damage due to impact, frost, or point loads are all defects of occurrence. Damage that occurs to foundations is organized according to several viewpoints. See these major topics, each of which you'll see is subdivided into more detail:
   1. FAILURES by FOUNDATION TYPE & MATERIAL
   2. FAILURES by FOUNDATION MOVEMENT TYPE
   3. FLOOD DAMAGE TO FOUNDATIONS
   4. FOUNDATION CRACK EVALUATION
   5. SLAB CRACK EVALUATION
      
4. Defects of Omission: Observe defects of omission - things that have been left-out or removed (harder to spot) such as possible absence of supporting posts, piers, footings, or other critical components. Defects of omission are not an event that happened to a foundation, but rather things that were forgotten or removed, such as omitting footings or removing a supporting Lally column in a building. See FOUNDATION DEFECTS OF OMISSION.
5. Evaluate Observations: Evaluate the information which has been collected (history, observations, clues), visual evidence of their impact on the structure, and their importance. Any building inspector, building contractor, masonry repair contractor, or carpenter needs to be able to recognize when additional expert evaluation or repair is needed by a foundation or structural engineer or foundation repair specialist.
   
   All of these people are called-on to make first-level inspections and to form opinions about all sorts of building components. Often very simple non-engineering analysis can be helpful or even essential in deciding when more expert help is needed. Examples include simply making a measurement to establish that a foundation wall has moved or is leaning. See
   1. FOUNDATION CRACK EVALUATION
   2. FOUNDATION BULGE or LEAN MEASUREMENTS
   3. FOUNDATION DAMAGE SEVERITY
   4. FOUNDATION MOVEMENT ACTIVE vs. STATIC
   5. SLAB CRACK EVALUATION
6. Report Observations & Make Foundation Repair Recommendations: Communicate the observations and recommendations to the client with clarity so that the client understands the implications of the findings and the need for action (if any). See FOUNDATION DAMAGE REPORTS
7. Repair the Damaged Foundation: depending on the condition of the foundation system, repairs may be needed, and in emergency cases such as the threat of imminent collapse, other measures such as installation of temporary foundation support, or even evacuating an unsafe structure and keeping people away from it could be in order. An example is the discovery of a bulged structural brick wall - a condition that can cause sudden catastrophic building collapse. See FOUNDATION REPAIR METHODS

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Use links just below or 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 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

• "Quality Standards for the Professional Remodeling Industry", National Association of Home Builders Remodelers Council, NAHB Research Foundation, 1987. See our books at "Structure" at the InspectAPedia Bookstore
• "Concrete Slab Finishes and the Use of the F-number System", Matthew Stuart, P.E., S.E., F.ASCE, online course at www.pdhonline.org/courses/s130/s130.htm
• 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
• Aaron Kuertz aaronk@appliedtechnologies.com, with Applied Technologies regarding polyurethane foam sealant as other foundation crack repair product - 05/30/2007
• 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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