Dallas Fort Worth Flood Damage to Foundations

Below we give a detailed list of questions to ask and inspections to make in assessing whether or not a building foundation damage or crack was caused by flooding

A catalog of types of damage that occur in masonry block foundation walls is atBLOCK FOUNDATION & WALL DEFECTS .

In sum, the building inspector seeing this structure after flooding has occurred needs to:

• Determine if the building was exposed to flood waters, and if so, determine the level of flood water that was encountered.
• Compare flood water levelsto the depth of the foundation below grade.
• Look for evidence of damageto the building: Examine the size, shape, pattern, age, and location of foundation cracks or other evidence of movement (such as tipping or leaning), and relate that evidence to the location of water and earth pressure on the building. Also relate that evidence to the history of foundation damage, movement, and water entry in the building.
• Identify both non-structural cracksor damage (such as a crack in a basement floor slab poured inside of a perimeter foundation) as well as cracks that involve the structure.
• Decide if the building is unsafe. If the inspector is not trained to make this assessment, a foundation engineer of an experienced foundation repair contractor should be consulted if there is evidence of foundation damage or movement that in the inspector's judgment affects the structure and its stability or safety. Certain types of masonry wall or foundation damage such as broken bond courses in a structural brick wall, can make a building very unsafe and could justify evacuation an immediate temporary support.-- BRICK FOUNDATION & WALL DEFECTS .
• Decide if the building needs repair, and understand the cause of the damage sufficiently to suggest an effective repair if repair work is necessary.

Fine Vertical Cracks in a Masonry Block Foundation Wall - Caused by Flooding?

Complaint/observation: hairline vertical crack in a masonry block garage wall. This photo shows the interior surface of the garage wall in the picture we provided above.

The building owner did not know if these cracks were present before the building had been subjected to flooding, but he posed that the damage was due to flooding and had pressed an insurance claim.

The foundation inspector has multiple obligations: she or he has a general obligation to protect the safety of a building's occupants by being able to recognize if the structure is unsafe and needs repair (if that is within the scope of the inspector's expertise). The inspector needs to accurately diagnose the cause of the damage, not only for insurance claim purposes, but also because without an understanding of the cause, the need for repair, and the proper repair may not be specified.

Key diagnostic observations:In this foundation wall there was no bulging, bowing, or leaning observed in the wall. Other walls in the same building were not damaged.

This masonry block foundation crack photo was provided by Bob Maltempo , an engineer who inspects foundations for damage. Maltempo observed vertical hairline cracks in the masonry block foundation, at regular intervals of this building which was constructed in the 1950's on Long Island in New York

Fine vertical or near-vertical cracks in a masonry block foundation may be caused by shrinkage in the concrete blocks - a condition that occurs shortly after construction. Shrinkage cracks in masonry tend to be uniform in width, top to bottom, but might be more narrow at the crack bottom where the masonry blocks are pinned to a (presumably not shrinking) footing.

Fine vertical or near-vertical cracks in a concrete block wall may also be caused by footing settlement. If that cause is present, careful measurement should find that the wall is not at exactly the same height on both sides of the vertical crack.

Floodwaters around a building, if they press principally on only the wall exterior, can cause a wall to buckle, bend, or lean inwards. These pressures often cause horizontal cracking in a masonry block wall; vertical cracks would be unusual. That pattern of movement was absent from this home.

How would a flood cause a vertical crack in a masonry block foundation wall? Floodwaters or even wet soils around a building might cause footing settlement, particularly in a newer building whose footings may have been placed on poorly-compacted soil. That pattern of movement was also absent from the home.

Since floodwaters would be expected to surround a home built on a relatively flat lot, one would also seek to determine why only one wall of the building was affected. There could be explanations for that asymmetry.

Our opinion was that the cracks in this masonry block wall were chiropractors of masonry block shrinkage, that they were most likely caused by that effect and not caused by flooding.