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Find & hire a foundation engineer or contractor:
This article describes how to choose a foundation crack diagnostic engineer or contractor, how to choose a foundation repair expert, and how the expert will evaluate building foundation damage. This article series describes how to evaluate and repair foundation damage.
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. The page to photo shows the author (a long time ago) pointing out two different types ir areas of foundation leakage.
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Sketch of differential settlement (below left) is provided courtesy of Carson Dunlop Associates.
I'm going a little nuts here about this foundation crack and would love some guidance. When I bought my 100 year old home in Brooklyn a year ago, the basement side-wall right near the front of the house had a diagonal crack from a window to the corner. it's about 4 feet and starts a little wider and gets smaller. This sidewall is on the detached side of the house.
A few weeks ago, I noticed a new, very thin horizontal crack. After researching it, I realized it goes almost the full length of the house. It wavers up and down a little, but is mostly a little above grade and near the middle of the wall. Next to this wall is an unused driveway (it's actually too small for a car...so it really hasn't been used).
I've now seen 4 contractors and gotten very different opinions.
Foundation contractor #1, Modesto (20 years experience in masonry -- though not foundation cracks) says not to worry. it's not serious.
Foundation Repair Contractor #2, Quality First, which specializes in foundation repair, says it's due to outward pressure from the soil under the driveway pushing horizontally against my basement wall and that eventually the wall could bow. They recommend a 5k fix including epoxy and carbon straps. The guy seemed very knowledgeable, had a great sales pitch and tons of materials and references.
Foundation repair contractors #3 and #4: Two other contractors suggest the cracks might be due to moisture and suggest taking out the broken areas, re pouring concrete and adding some steel in the area with the "more serious" diagonal crack. Neither specialize in foundation work., but both were experienced.
I'm kinda at my wits end with time and money and appreciate any advice. Best, - BL
A competent onsite inspection by an expert who is familiar with the causes and cures of foundation damage usually finds additional clues that help accurately diagnose a problem beyond what would occur to a homeowner to describe in email. Put another way, we cannot reliably diagnose the cause, nor evaluate the significance of a crack by email text description, though knowing the type of foundation material, site characteristics, drainage issues, and seeing some photos, measurements, and building history would help. That said, here are some things to consider:
Some foundation cracks are insignificant, and are easily and immediately recognized by an engineer, contractor, even most home inspectors who have experience. For example, most concrete slab or wall shrinkage cracks are not structural in nature.
Diagonal foundation cracks are often from settlement or on occasion frost heave at a building corner. On occasion, lensing - frost sticks to and lifts a foundation. In extreme cases of horizontal foundation movement, diagonal cracks may of course appear at building corners, especially in block or brick foundation walls.
at SETTLEMENT IN FOUNDATIONS
Horizontal cracks in foundations are typically from frost pressure, earth pressure, or other loading against the foundation wall. The height of the crack in your description, as it's closer to the top of soil, suggests it may be due to frost pressure on the wall (check roof drainage at that wall - notice if the wall is below a roof eaves (likely) or at the gable end of the home (no roof spillage, less likely).
Complex foundation damage includes multiple crack or movement patterns - that does not sound like your case.
Old Foundation cracks Can "Suddenly" Appear in Our Consciousness. Of course it's possible that that horizontal crack has always been there, caused by earth loading by heavy equipment that drove close to the foundation wall during the time that the driveway was constructed. Often a crack in a foundation is present for years but goes unnoticed until something gets people worried. Then it suddenly "appears". A careful inspection of the interior of a a crack can often tell us if it's new or old.
The total amount of foundation movement that has occurred
The rate of of foundation movement
The impact of foundation movement on the structure - water entry, or loss of structural stability.
The cause(s) of foundation movement
A foundation expert may also consider:
The foundation materials: what was used. For example, a crack in steel-reinforced poured concrete foundations has different implications from the same crack size, shape, location, pattern in a masonry block foundation. For non-trivial foundation damage, the inspector, engineer, or contractor may want to identify the building foundation construction type, materials, sequence of construction - the history of the site, the foundation itself, and its construction details.
Site factors affecting the structure such as slope, drainage, rock, or nearby activities such as blasting.
The construction type, materials, sequence of construction - the history of the site, the foundation, and its construction details.
Watch out: As we introduce at our home page for this topic
at FOUNDATION CRACKS & DAMAGE GUIDE, since certain masonry structure defects, such as even slightly-bulged structural brick masonry walls (above or below ground level |
see BRICK FOUNDATIONS & WALLS
or severely bulged below-ground masonry block or stone foundations,
See BULGED vs. LEANING FOUNDATIONS) can lead to sudden precipitous and catastrophic building collapse, dangerous conditions may be present at some properties.
While there are often hidden conditions which can disguise building conditions, the ability to recognize those potentially urgent or dangerous conditions which can be detected is important in a foundation inspection.
Watch out also and avoid or at least defer non-urgent repairs that may be unnecessarily costly in comparison with the impact of the crack on the structure or that fail to first identify and understand the cause of the foundation cracking and second to evaluate and understand its impact on the structure.
Some fellows who work in construction are very experienced, knowledgeable, and honest, but they were not English majors in school. You have to ask to hear more of the contractor's reasoning before you'll be comfortable with an answer like "Nah, don't worry about it!" much less "Yeaaah, this is a big problem and needs a big expensive repair."
In addition to the outline of how we approach foundation inspection found (described beginning
at FOUNDATION INSPECTION METHODS), here is some basic advice about how to evaluate foundation damage:
If it is not apparent that a major problem exists (see our Watch out: warnings throughout this website) it's ok to start with a contractor. 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 constantly 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.
Evaluate the information which has been collected (history, observations, clues), visual evidence of their impact on the structure, and their importance.
When the foundation expert you are consulting suggests that costly or dangerous conditions exist, it is important that you have an accurate understanding of the problem and that the repair is appropriate. A professional foundation inspector, engineer, architect, or contractor should be able to communicate her/his 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 for details.
For costly or potentially dangerous foundation damage, be sure that your "expert" really is one.
A civil engineer or structural engineer who is specifically experienced in building foundation diagnosis and repair can give reliable and often economical advice on what foundation repair is needed. So can some experienced foundation repair contractors.
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
Watch out for "foundation experts" who don't know foundations: OPINION-DF: even licensed professional engineers or architects who do not have specific experience and training in building foundations. Those experts can often design a repair that will be "safe" and "work" but we have found that some who are not familiar with foundations are not aware of repair products and procedures specifically designed for these problems.
The result can be "overkill" or a foundation repair design that was more complex, more disruptive, and more expensive than necessary.
At Vertical Foundation Movement Repairs we mention a case where just this problem occurred at a home built over a landfill.
FOUNDATION CRACK DICTIONARY - how do we evaluate and diagnose the type of crack in a foundation
FOUNDATION BULGE or LEAN MEASUREMENTS - how do I measure the amount of foundation movement that has occurred
FOUNDATION DAMAGE SEVERITY - how bad is the foundation crack? how urgent is repair
FOUNDATION MOVEMENT ACTIVE vs. STATIC - is the foundation crack a sign of ongoing movement?
CONCRETE SLAB CRACK EVALUATION - for evaluating cracks in concrete floors or in poured concrete monolithic slab-foundations
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