Common Causes of Foundation Movement
Photo by Brett Jordan
Originally Posted On: Common causes of foundation movement — Foundation Pro Engineering
A variety of factors can cause your home’s foundation to move, which can cause serious and costly damage. We’re here to help you better understand what causes foundation movement and how to spot the signs.
The Most Common Culprit…Water!
A water event, such as a broken or leaky pipe, over-irrigation, or poor grading and drainage can cause significant swelling, collapse or subsidence of the soil on your property. In Colorado, much of the state has soils with moderate to very high swell potential. These expansive soils, such as clay, absorb moisture and can swell up to three times their volume. Likewise, this soil also shrinks significantly in periods of dry conditions or drought, causing soil shrinkage that also may affect your foundation.
You can help protect your property by doing the following:
Make sure there is proper grading (+5% is common) to drain moisture away from your house.
Install extensions on gutter downspouts to direct rain water away from your house.
Fix any plumbing leaks immediately. These don’t have to be inside your home either. Watch for leaks in your irrigation system around your property. Keep an eye on your water bill for excessive usage.
Rapid urbanization and land development may impact the global groundwater level beneath your house. Developing barren land into tightly spaced homes interlaced with paved driveways, parking lots, and roadways can drastically reduce the amount of groundwater which naturally evaporates from the soil surface causing the water table to change. Options are available to determine if this is the case, and to mitigate the issue.
Improper Selection and Design of the Foundation
If little is known about the soils, the proper foundation may not be adequately selected, and foundation-related issues may result. Typically, a geotechnical study for a specific project will give foundation recommendations to help decide which foundation type is best. If a geotechnical report was not conducted, or if it was not followed, the foundation could be undersized or improper altogether. In cases with poor soils, deep foundations are utilized to bypass the poor soils. Deep foundations may consist of micropiles, helical piers, or other drilled caissons. If the foundation at your home was not designed for the soil conditions, poor performance may occur. There are options to remediate and upgrade a shallow foundation to a deep foundation.
There are three common types of foundations used in most home construction: slab-on-grade, crawlspace with stem walls and footings, and full basement walls with footings. The soil must be compacted to specific standards before building with any of these foundations. Improper compaction and soil preparation during construction can lead to excessive settlement or heave of the soil, thereby causing foundation problems. If you suspect this is the case, contact us right away for inspection. You may also find this article helpful.