Is your house moving? It probably is and it’s not as unusual as you might think. According to a recent nationwide survey by Criterium Engineers, structural movement is one of the most common concerns of homeowners. And, it is often the soil underneath the home that’s the cause. The Criterium Engineers survey was based on information gathered from 65 offices across 35 states. Each office provided a list of the most common homeowner concerns as recorded by its engineers. Responses found that some structural movement is common to homes of all ages. Criterium Engineers collectively inspects 25,000 homes per year.
“Homeowners need to investigate thoroughly the reason for their home’s movement. Temperature and humidity changes can cause shrinkage in lumber. That shrinkage, in turn, can crack interior finishes. But those two changes are not necessarily signs of structural movement. If there is significant cracking or movement, however, then soil conditions may be the cause.”
Results of the survey revealed seven problem areas stemming from moving or unsound grounds:
Unstable soil . The soil underneath the home may consist of granular material or fine-grained clay. Considered not very stable, clay is more sensitive to changes in its moisture content. Heavy rains can then cause structural movement in this type of soil.
Eroded sloping sites. While the hillside view may be great, soil erosion mixed with heavy rains can degrade the soil structure – and your home may tumble after.
Earthquakes. After an earthquake, soil movement may have caused the home to shift. Even minor tremors can affect soils in ways that may not show up until months later.
Curved roads. Vehicles repeatedly turning the curve impact the outlying soil. Homes built along the side of curved roads or in cul-de-sacs can eventually feel the effects of local traffic.
Non-uniform soil. If part of a foundation is on one type of soil while other parts are on another, shifting can occur since the varied soils perform differently.
Rock ledge. If the home is partly built on a rock ledge, the soil under the remaining portions may consolidate and cause uneven settlement.
Improper soil preparation during construction. Most soils must be thoroughly compacted before construction to accept the additional weight of the new home.
Structural movement resulting from soil performance is so widespread that entire industries have emerged to address foundation repairs and stabilization. Some companies specialize in foundation underpinning and foundation wall reinforcement. “The effects of soil problems can be minimized by thorough soil evaluation before construction. However, this is not commonly done for residential construction. So, the homeowner is often left with the unpredictable. Homes do move and will continue to move.”
Criterium-Bennett Engineers recommends that if you suspect your house is moving, then monitor it for at least 6 – 12 months. Take careful measurements at least every three months to quantify the movement. If necessary, contact a qualified expert for further evaluation.