Photograph of - bowed foundation wall, probably from frost cracking. Drop a plumb line to measure total inwards bulging of this block foundation wall.Block Foundation Wall Backfill Damage
wavy mortar in joints

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Horizontal-cracked block foundation damage:

Horizontal cracks, bulging, leaning due to damage during construction: this article describes the types & causes of horizontal cracks in the mortar joints of a concrete block wall or foundation wall that is damaged during original construction, typically during backfill.

We point out a special type of crack showing wavy, unbroken mortar as compelling evidence of the time of damage occurrence: before the mortar had hardened. The article notes that combinations of block foundation wall damage may be present and should be identified and evaluated. The page top photo shows a combination of open mortar joint in the block foundation wall and significant inwards bowing of the wall; this wall may be in danger of collapse.

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Wavy Mortar in Concrete Block Walls - is the wall collapsing?

Concrete block foundation damaged during construction Wavy mortar in concrete block wall (C) Daniel Friedman

Wavy mortar indicates damage to the block foundation during backfill (C) Daniel FriedmanWavy mortar foundation cracking: Our photo at left and the photos shown above right illustrate open crack sin the concrete block foundation wall of three different older homs. These wavy mortar cracks were detected in a home's basement.

The wavy mortar is not a shrinkage crack.

The photos include another nice clue that forms a compelling argument about when and probably how this foundation crack occurred.

The un-broken but wavy mortar in the joint between the concert blocks tells us that this wall was pushed inwards at the time of new construction, before the mortar had hardened.

Perhaps if the builder had waited for her block foundation wall to cure before pouring the garage slab (or had reinforced the block wall) this crack would not have occurred.

Watch out: because combinations of forces can be at work on a foundation wall that seems "cracked" or damaged in any way, it is possible to have both old movement that occurred at the time of backfill or construction (wavy mortar that is not broken) and more recent ongoing movement and damage from any of a variety of causes.


Continue reading at BULGED FOUNDATION REPAIR METHODS or select a topic from the More Reading links or topic ARTICLE INDEX shown below.


Or see FOUNDATION CRACK DICTIONARY for descriptions of different crack patterns, causes, repairs

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BLOCK FOUNDATION BACKFILL DAMAGE at - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.

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