Soils in Colorado tend to be expandable—meaning they gain volume, or “swell” when wet or frozen. This swelling is very strong, and can shift entire foundations of even the largest homes (though usually only by an unnoticeable amount.)
Because basement walls sit directly on top of the home’s foundation, this makes them susceptible to moving when the ground becomes saturated with rain or when temperatures dip below freezing. Floating the basement walls allows the soil to expand without adversely affecting the home. This method, while effective, is not entirely fail-safe, and even if your basement walls are floated, the ground can still move enough to make small cracks appear in the drywall or in the floor tiles. However, these are just cosmetic concerns, and generally don’t affect the overall integrity of the structure. You can see a photo of a floating wall below.