Submitted by DonHester on Tue, 05/15/2012 - 07:03.
The two rules of Concrete- Chelan and Leavenworth Home Inspection
The two rules of concrete that are universally recognized as that it will get hard and it will crack.
A good concrete contractor will control those cracks and they should not be much of an issue.
But there are some other rules that are very important.
Rule 3- If you do not properly prepare the sub-surface for the concrete and control the water your concrete will act like tectonic plates and go into motion.
During a home inspection all too often I see where the sub-grade for the concrete pours have not been properly prepared and the home will suffer from concrete breaking up, settling and moving. This is not only unsightly but in many cases becomes hazardous.
(Here is an example of poor preperation)
If the ground (sub-grade) has been disturbed (like by the foundation) it will need to be compacted in lifts to create a stable surface. The sub-grade should be hard, level, uniform and free of debris.
Rule 4- Your concrete should not spall. This inflection is most common in northern climates where freeze/thaw cycles occur and deicers are used.
Concrete is porous and if the concrete does not have a proper admix, or there is too much water in the slurry, or has been over worked it will create a weak layer on the top of the concrete that is susceptible to water damage.
Concrete is really like a sponge and water is absorbed into the very fine capillary spaces and hairline cracks. When water freezes, it expands by 9%. This expansion will cause the surface layers to flake and come loose.
The biggest problem with these issues is it usually will not become apparent for some time. Hiring quality contractors will be your best insurance from some of these issues.
Here is a good video on concrete spalling- Spalling Video
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Albert Einstein
NCW Home Inspections, LLC is a Licensed Washington State Home Inspection service located in Wenatchee Washington serving Chelan County, Douglas County, Kittitas County, Okanogan County and Grant County Washington and the cities of Wenatchee, Leavenworth, Cashmere, Orville, Cle Elum, East Wenatchee, Quincy and many more… Your Wenatchee and Chelan Professional Real Estate, Home and Structural Pest Inspection Service