How much concrete cracking is normal?

If the crack is larger or larger (an “active crack”), or if one side of the crack is higher than the other, you may need a structural engineer to review the work. Email address required Invalid email address Invalid email address ACI Resource Center Southern California Midwest The page may have been updated, moved or deleted. Also be sure to check your spelling. How do I find the page I wanted? Search the site with our specific Topics page.

Talk to a customer service representative now to help you find what you're looking for. Use the main navigation at the top of this page to find what you're looking for. Enter this 5-digit unlock code on the website. Read here about methods for curing concrete and understand how your contractor will cure concrete.

These control joints are designed to weaken concrete in certain areas, so that concrete cracks in a straight line in these spaces. Basically, a cold joint is where you pour one section of concrete and then, once it has hardened, another section of concrete is poured next to it. If a structural contractor drives a piece of heavy equipment loaded with wood onto a 4-inch thick concrete slab, it can crack green (not fully cured) concrete. They can be troweled into concrete or thin strips of plastic can be embedded in fresh concrete to weaken it.

However, a large majority of concrete used in residential work has too much water added to the concrete on the job site. If these sublayers are not well compacted, when concrete is poured onto them, the heavy weight of the concrete will cause these areas to sag a little, and then cracks can occur. In general, cracks wider than a credit card and running through the depth of concrete are structural in nature and could be a sign of more serious problems (see Evaluating Concrete Crack Repair). But it's important for concrete contractors to follow well-established guidelines regarding concrete placement.

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