Soils are modified over time by many things: the erosion off the mountains, the creeks running along the base of the mountains, and the seasonal moisture fluctuations (i.e. For example, what makes central and eastern Colorado different from other areas is our close proximity of the Front Range, and the transition from plains to mountains. The geology of a region, as well as the manner in which soils were deposited over time, can change the specific soil characteristics. All are unique, but share certain characteristics as far as how they behavior during the construction of homes, septic systems, and retaining structures. This has led to regional terms for clays such as Bentonite, Georgia Clay, Caliche, and Gumbo, among others. Q: Are expandable soils unique to Colorado, or are they found in other states or regions?Ī: Many locations around the country have expandable clay soils. So for all practical purposes, it’s best to refer to them as “expandable” soils. “Shrink-swell soils” merely describes how the same soil that expands when wet will often shrink or reduce in volume when it dries.“Expanding soils” is an improper term in that it conveys the certainty of expansion, rather than just the potential.“Swelling soils” is sometimes used interchangeably with “expandable soils.”.Are these all the same, or different, and which is the proper term? Q: There are lots of terms out there: expanding soils, expansive soils, expandable soils, shrink-swell soils, swelling soils, and more.

Minus 200-size particles are similar to talc or flour in consistency. This leads to a common term of “minus 200” soil when discussing the topic. Clay and silt particles can pass through an opening 1/200th of an inch in size. They also share a common characteristic of being very small in size. All have specific individual properties, but share an affinity for water and will draw it to the soil whenever possible. I say “clays” and “silts” in the plural because there are actually a number of differing clay molecules as well as silt types. The two most common types are Clays and Silts. Expandable soils can cause cracking in your walls and foundationĪ: The term expandable soils refers to a group of soils that can change volume when provided exposure to water.

House floating foundation erosion