Expansive soil and cracks in exterior walls

[Jeffrey R. Pope]

http://geology.com/articles/expansive-soil.shtml

[Randy L. Mayo, PE]

Jeffrey

Those links you have listed contain the general soils map I referred to as misleading.

In southern Missouri where I live the map shows (brown) or no expansive soil.

This could not be further from the truth. Next to getting a site specific soils test the USDA soil survey I referred to will give you a much better idea of the local soil types. The attached picture shows a section of a soils map from the county I live in and you can see the lines outlining the different soil types in a small area. My county has 55 different soil types listed and each soil type is composed of several layers with each layer having different soil properties. So don't use that US soils map to make any assumptions about the soil in any specific location.

[Randy L. Mayo, PE]

Jeffery

I forgot the map....

[Tim Spargo]

Is this http://websoilsurvey.nrcs.usda.gov/a...oilSurvey.aspx the resource your talking about Randy?

[Randy L. Mayo, PE]

Tim

That is a source for the data. I have not use their web site but the data is there. Once you identify your location I would look under the Soil Properties & Qualities tab then on the left click on the Properties and Qualities Rating section, then Soil Physical Properties, Then Linear Extensibility. You will have to just plow your way through this web site. I got the actual maps and book from my USDA office for my area, its much faster than going online.

[Tim Spargo]

Thanks Randy. Another source of info never hurts.

[Jeffrey R. Pope]

I removed the direct link to the map, but the article is a good basic source of information. Use it at your own risk/discretion