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STRUCTURAL INSPECTIONS & DEFECTS
AGE of a BUILDING - how to determine
BRICK FOUNDATIONS & WALLS
CHIMNEY INSPECTION DIAGNOSIS REPAIR
COLD POUR JOINTS, CONCRETE
COLUMNS & POSTS, DEFECTS
DISASTER BUILDING INSPECTION & REPAIR
EARTHQUAKE DAMAGED FOUNDATIONS
FLOOD DAMAGE ASSESSMENT, SAFETY & CLEANUP
FLOOD DAMAGE TO FOUNDATIONS
FOOTING & FOUNDATION DRAINS
FOOTINGS EXPOSED, Repair Methods
FOUNDATION BULGE or LEAN MEASUREMENTS
FOUNDATION CONSTRUCTION TYPES
FOUNDATION CONTRACTORS, ENGINEERS
FOUNDATION CRACKS & DAMAGE GUIDE
FRAMING DAMAGE, INSPECTION, REPAIR
GRADING, DRAINAGE & SITE WORK
GUTTERS & DOWNSPOUTS
INSECT INFESTATION / DAMAGE
MOBILE HOMES, DOUBLEWIDES, TRAILERS
MODULAR HOME CONSTRUCTION
MOISTURE CONTROL in BUILDINGS
RETAINING WALL DESIGNS, TYPES, DAMAGE
RETAINING WALL GUARD RAILINGS
STRAW BALE CONSTRUCTION
STRUCTURAL DAMAGE PROBING
STRUCTURAL WOOD ASSESSMENT
THERMAL EXPANSION of MATERIALS
TIMBER FRAMING, ROT
WATER BARRIERS, EXTERIOR BUILDING
WATER ENTRY in BUILDINGS
WINTERIZE A BUILDING
Guide to foundation damage repair methods for bowing, cracking, leaning, settling or other types of foundation damage: This article series discusses How to Repair Damaged Foundations, Foundation Cracks, Slab Cracks, Bowed, Buckled, Leaning Foundation Walls, Settled Floors.
The photo above shows a bowed masonry block foundation wall with horizontal cracking that occurred due to earth loading at the time of construction, probably by vehicles driving too close to the foundation wall shortly after it was constructed 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 and the repair methods needed for foundation damage, cracks, leaning, buckling, bowing, settlement.
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Repair Methods for Foundation Shrinkage Cracks
Before repairing a foundation crack it is important to diagnose the cause of the crack and its effects on the building structure.
The significance of any foundation crack depends on the crack's cause, size, shape, pattern, location, foundation materials, extent of cracking, impact of the crack on the building, and possibly other factors as well. If there is an underlying ongoing problem causing foundation movement or damage, that problem needs to be corrected too.
Cracks in poured concrete walls that are larger than 1/4", cracks which are increasing in size, or cracks which are otherwise indicative of foundation movement should be evaluated by a professional.
At Do we need to repair shrinkage cracks in foundation walls or slabs? we discuss how we decide if a foundation crack needs repairing the first place.
The diagnosis and evaluation of foundation cracks and structural foundation damage and repair methods are discussed extensively at FOUNDATION REPAIR METHODS
Suggestions for Repairing Concrete Foundation Shrinkage Cracks
Repairs to foundation cracks which are not traced to building movement, structural problems, site problems, or other conditions which require site or structural repairs may be attempted for cracked foundations and other cracked concrete structural elements using a variety of products and materials such as masonry repair epoxy or sealant products.
These products, some of which include even structural repair epoxies, might be used to seal against water leakage as well, and may be used for repairing certain cracks in concrete foundations following evaluation and advice from a foundation professional. An evaluation of the presence, absence, or condition of reinforcing steel in cracked concrete foundations should be a part of such an inspection.
Shrinkage cracks, which are not normally a structural defect in a building, may nonetheless need to be sealed against water entry. Common repair methods include chipping out the crack and applying a masonry patching compound to the surface, use of epoxies, or other sealants.
Water entry leaks at foundation cracks: Polyurethane foam sealant is used for foundation crack repairs to stop water entry. (Also find and correct outside water sources). See our article on Using Polyurethane Foam for Foundation Repairs for details on using this product to seal foundation cracks against leakage.
For various methods and products used to seal cracks in concrete floors or walls, see SEAL CONCRETE CRACKS, HOW TO a description of various products and methods used to seal or repair cracks in poured concrete walls, foundations, floors, & slabs.
Once any concrete cracks it is possible for water to leak into the building through the crack. There are several ways to repair a basement crack leak. An easy, quick, and effective measure to stop basement or crawl space water entry through a foundation crack is to perform an injection of polyurethane foam into the basement crack. [Also be sure to find and fix the sources of water outside.]
Water entry leaks at foundation cracks: Polyurethane foam sealant is used for foundation crack repairs to stop water entry. (Also find and correct outside water sources).
Cracks at Control Joints in Concrete explains how we prevent shrinkage cracks in poured concrete floors and walls
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.
As movement appeared to be ongoing over more than a year, the builder might have repaired the foundation by supporting it from below using one of the methods listed at Vertical Foundation Movement Repairs.
Additional details provided at Vertical Foundation Movement Repairs include descriptions of grout pumping to stabilize soils or elevate slabs, slab jacking to stabilize or lift settled slabs over deeper unstable soils, the use of driven steel pins to stabilize settling foundation walls or footings, the use of helical piers or "screw piers" such as those provided by A.B. Chance to repair sinking foundations or to level floor slabs, and a similar use of friction piers such as those provided by Magnum piering - are driven piles which rely on soil friction against the sides of the pile.
Since it's sometimes the only appropriate repair method for foundation damage, we also illustrate foundation reconstruction.
The motive for a decision to reinforce a building foundation rather than rebuild it can be easily understood by noticing the difference in cost between bolting a few vertical steel beams to a building or building a pilaster and the cost to add temporary support to the floors above, remove an existing foundation, and rebuild a new one in its place.
However the decision to support or reinforce a foundation wall versus rebuilding it is often made by the wall itself. If the amount of bulge or bow is sufficiently severe the wall needs to be rebuilt.
If the underlying source of wall damage cannot be reliably addressed without excavating outside to add drainage and perhaps water proofing, there is additional motivation to perform a more costly repair.
The foundation bulge or lean repair methods listed below are shown roughly in order of their most common appearance in residential buildings. The sketch shown here describes application of a steel I-beam against a masonry block wall for reinforcement. More details are given below.
Repair methods for bulged foundation walls are illustrated and discussed in detail at Bulged foundation Repairs where we describe the use of pilasters, reinforcing steel I-beams, foundation anchors, sister walls, steel cables, and even complete foundation wall reconstruction to deal with foundation wall bulging, cracks, leaning, or movement.
Opinions herein are the responsibility of the author. Most of this material has been subject to ongoing peer review but is without any professional engineering analysis. Home inspections may include the discovery of defects involving life, safety, and significant costs. Home inspectors who are not both qualified and certain of the authoritative basis of their conclusions should obtain their own expert advice from qualified experts.
This work is also based on the author's construction & inspection experience, training, research, and survey of material from ASHI, and from N. Becker, R. Burgess, J. Bower, D. Breyer, A. Carson, J. Cox, A. Daniel, M. Lennon, R. Peterson, J. Prendergast, W. Ransom, D. Rathburn, E. Rawlins, E. Seaquist, and D. Wickersheimer. Some useful citations are at the end of this paper.
FOUNDATION INSPECTION STANDARDS - Foundation Inspection Standards - ASHI Standards of Practice (American Society of Home Inspectors)
4.1.A.1. The inspector shall ... observe foundation
4.2.A.1. ... describe the type of foundation
4.2.E. ... report signs of water penetration/harmful condensation
Notice that in some Standards there was no mention of observations of damage or unsafe conditions!
But notwithstanding Section 4.1 above, the following section requires the inspector to observe and report evidence of significant damage, including to visible portions of the foundation. Significant in this case means in need of immediate major repair; it might also mean in need of further evaluation by a qualified expert.
2.2 inspectors shall ... 2.2.b.3. ... state ... any ... components
... in need of immediate major repair
2.3 These Standards are not intended to limit inspectors from
2.3.A. reporting observations and conditions in addition
Strategy for Building Foundation or Floor or Slab Crack, Damage, or Movement Assessment
To understand the cause, effect, and remedy for all types of building foundation or masonry wall damage or movement we have categorized foundation damage into these broad categories:
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Frequently Asked Questions (FAQs) about repair methods for cracked or damaged foundations or slabs
Questions & answers or comments about foundation repair methods and procedures: repairs to foundation cracks, gaps, movement, tipping, leaning, settlement, or footing damage
Check the FAQs just above, try the search box just below, or if you prefer, post a question or comment in the Comments box below and we will respond promptly.
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Technical Reviewers & References
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NOTE: Journal of Light Construction articles are available on CD ROM from the Journal of Light Construction, www.bginet.com, 802-434-4747