Tackling the Issue of Foundation Settlement

Foundation settlement is an issue common in houses after a few years of their construction. It happens when the underlying soil shifts or compacts as a result of construction on previously disturbed (non-virgin) soil, or of backfills, changes in soil conditions, and moisture. While this movement doesn’t typically have a significant effect on the structuring of a house, it may lead to bigger operational and structural problems.

After settlement, there may be signs of cracks developing in the foundation, ceilings, or walls of the house – small, hairline-sized cracks, typically, which are a result of minor settlement, expansion and contraction, or possibly even movement in a season or cycle. Major settlement, however, is a result of significant or even severe foundation movement, which causes problems with a homeowner’s windows, doors, plumbing lines, or mechanical equipment. Professional home inspections can help identify these settlement-related cracks, which are usually more than a quarter of an inch wide. This is not to say that smaller cracks should be ignored; these may lead to multiple cracks, which can enlarge and present more serious issues with a house’s structure.

Perhaps one of the most telling signs of settlement-related problems in a house is when the property has a full concrete slab foundation or masonry veneer construction. To address this, homeowners may consider reinforcing the actual slab construction – to limit movement of the slab and prevent damage.

Apart from natural conditions, the causes of foundation movement and settlement may be attributed to improper construction and deficiencies in design. Things like building on soil with lots of voids or constructing on fill soil that’s not compacted properly can cause movement in the foundation. There are even cases when excessive excavation for the foundation footing – coupled with careless backfilling – accounts for foundation movement.

Settlement occurs when the compacted soil reaches a point of stability. If, for example, the soil of the house contains organic or man-made materials, which might contain voids and deteriorate quickly, then settlement is likely to occur – until such point that full (stable) soil compaction is reached.

Sometimes, mining operations, collapsing limestone caverns, frost heaves, and other natural phenomena can cause settlement of soil over a large area – this is called subsidence. It’s typically attributed to the compaction of sand or clay soil layers on the subsurface, brought about by the withdrawal of water, oil, or gas from underground. Owing to the sheer size and the slow rate of this settlement, its effect can be experienced long-term.

Expansive clay soils in particular present major concerns with foundation movement. That’s because it can shrink and swell depending on the season and on levels of moisture in the soil. With this cyclical movement comes potentially greater risk of damage, as it can affect the foundations and other parts of the home.

Houses in areas of Chicago neighborhoods – as well as of other cities and states – with expansive clays must be inspected, monitored, and maintained at all times. It’s also important to ensure that the moisture levels of the soil around the house are relatively balanced. Things that can lead to the drying of the soil include irregular and uneven lawn watering and changes in the level of subsurface water, both of which can lead to the occurrence of settlement. Meanwhile, if the soil becomes too moist. and therefore swells, something as dramatic as foundation upheaval may occur.

It’s always smarter to be on the safe side and call for an evaluation of your house’s foundation occurs. This can be done by professional home inspectors, engineers, and other qualified specialists.