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STRUCTURAL INSPECTIONS & DEFECTS
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CHIMNEY INSPECTION DIAGNOSIS REPAIR
COLUMNS & POSTS, DEFECTS
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DECK & PORCH CONSTRUCTION
DEFINITIONS of MOBILE HOME, DOUBLEWIDE, MODULAR, PANELIZED CONSTRUCTION
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DISASTER BUILDING INSPECTION & REPAIR
EARTHQUAKE DAMAGED FOUNDATIONS
FIRE DAMAGE vs MOLD DAMAGE
FLOOD DAMAGE ASSESSMENT, SAFETY & CLEANUP
FOOTING & FOUNDATION DRAINS
FOUNDATION CRACKS & DAMAGE GUIDE
FRAMING DAMAGE, INSPECTION, REPAIR
GRADING, DRAINAGE & SITE WORK
HOUSE PARTS, DEFINITIONS
INSECT INFESTATION / DAMAGE
KIT HOMES, Aladdin, Sears, Wards, Others
LOG HOME GUIDE
MOBILE HOMES, DOUBLEWIDES, TRAILERS
MODULAR HOME CONSTRUCTION
MOISTURE CONTROL in BUILDINGS
PORCH CONSTRUCTION & SCREENING
PRE-CUT & KIT HOMES
RETAINING WALL DESIGNS, TYPES, DAMAGE
ROT, FUNGUS, INSECT DAMAGE
SINKHOLES, WARNING SIGNS
STAIRS, RAILINGS, LANDINGS, RAMPS
STRAW BALE CONSTRUCTION
STRESS SKIN INSULATED PANELS
STRUCTURAL WOOD ASSESSMENT
TIMBER FRAMING, ROT
TRUSSES, Floor & Roof
WATER ENTRY in BUILDINGS
WOOD STRUCTURE ASSESSMENT
How to repair concrete foundation shrinkage cracks: this article describes how to repair shrinkage cracks in poured concrete foundations. The photo above shows a typical shrinkage crack in poured concrete.
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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Diagnose the Concrete Crack Before Repairing It
Before repairing a foundation crack it is important to diagnose the cause of the crack and its effects on the building structure.
Our photo (left) shows a shrinkage crack (horizontal in the photo) near the corner of two control joints in a poured concrete floor of a Tucson Arizona home. (The insect fragments on the crack were left for scale).
We suspect that at this job the control joints were not properly formed, perhaps not deep enough. But of course a shrinkage crack could have occurred even with perfect control joints, depending on the concrete mix, site preparation, and the conditions at the time the mix was poured.
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.
Our photo (above-left) shows concrete shrinkage cracks in a new home in Pawling, New York. There was no water entry and no vertical movement in the slab (no trip hazard). Absent water or radon leaks or a trip hazard, these cracks were, in our opinion, of cosmetic concern only and did not need to be repaired for structural reasons.
Watch out: even an apparently harmless crack in a poured concrete floor should be repaired or bridged with an appropriate mesh tape and sealant product before installing ceramic tile over the floor, to reduce the chances that the crack later telegraphs through the tile.
How are Concrete Shrinkage Cracks Repaired?
Stopping 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.
Watch out: best practice in stopping water entry at any foundation crack (shrinkage, settlement, etc) is to find and correct the root cause: the source of water. See WATER ENTRY in BUILDINGS. Or if your foundation is excavated from outside, see WATER BARRIERS, EXTERIOR BUILDING.
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). See Polyurethane Foam Injection.
Repair of Foundation Cracks
For detailed information about foundation repair methods, including repairs to various kinds of cracks in concrete, see:
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Frequently Asked Questions (FAQs) about the repair of shrinkage cracks in foundations
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