How to Measure a Foundation Crack

Which DIY Concrete Crack Repair Kit Do I Need?

Some concrete cracks are uniform in width and others may range from being wider at top than the bottom or vice versa. It is important to measure the smallest width of the crack as the injection material needs to be able to penetrate this portion of the crack. A quarter coin is approximately 1/16" thick, so you can use one as a guide.

Example of a hairline crack
Example of a larger concrete crack


Single Component:

Measure the smallest width of the crack. If you try placing a quarter inside the thinnest part of the crack and it fits, use the FLEXKIT-100. Otherwise, use FLEXKIT-200.


Measure the smallest width of the crack. If the smallest width measures:

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Less than 1/16" wide
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Between 1/16” and 5/16”
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Wider than 5/16”


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Very hairline to very wide
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3/32" to 1/2"
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Hairline to 3/32"

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