WHY DO FOUNDATIONS SETTLE?

Your home is resting on several different layers/horizons of soil each with its own thickness, density, and load-bearing characteristics.

Some of these soils have been in place for thousands of years or more – placed there by wind, water, or glaciers.

Others were put in place by contractors as your home was built to create a level surface for your foundation to rest on. In this article, we are going to identify various causes of foundation settlement, including:

  •   Drought
  •   Maturing Trees
  •   Poor Drainage
  •   Busted Pipes & Leaking Water Lines
  •   Poorly Compacted Soil
  •   Weak Bearing Soil
  •   Moisture Content Changes
  •   Soil Consolidation

Why Do Foundation Settle?

Foundation Settlement is due primarily to the expanding soil cycle (shrinkage and expansion) directly dependent on water content. This constant movement weakens and softens soils and can also create pockets/voids beneath your home’s foundation, which your home will sink/settle into following the laws of gravity.

Identifying foundation settlement issues & Solutions

Foundation settlement damages usually stem from changes over time, rather than issues with the structure’s design, or lack thereof.

Read more: Why Do Pools Crack?

Foundation soil surrounds and supports your structure, but when changes in foundation happen (either foundation settlement or foundation heave) structural and cosmetic damage can occur.

Some of the most common issues that result in foundation settlement include the following:

Drought

During prolonged dry periods (as are common in Southern California and Arizona), the soil around your home may begin to dry out.

As clay soils dry out, they will shrink considerably. This is a telltale sign of expansive soil. When this happens underneath your foundation, your foundation will also settle, possibly leading to structural damage.

In short, turns out your home is susceptible to the laws of gravity.

When the foundational support shrinks, the house sinks.

Maturing Trees   

A mature tree’s root system can be up to twice the size of its visible part. If the trees extend over your home, that’s a good sign that they’re probably under your house as well.

As the root systems continue to expand, they draw up moisture from the soil beneath the foundation that can accumulate hundreds of gallons of water each day, causing clay-rich soils to lose moisture and shrink significantly – leading to settlement of the overlying structures. 

Poor Drainage

If water is allowed to pond next to the home due to poor soil grading, clogged gutters, or some other factor – the soil will absorb the water. If the soils around the home are clay/expansive soil, the home will sink into the sticky clay abyss.   

Busted Pipes & Leaking Water Lines

Plumbing leaks under or around a home can also saturate the soils around a foundation and potentially weaken the soil’s load-bearing capacity. This is similar to rain, except you foot the bill. 

Poorly Compacted Fill Soils

To make a level surface where your foundation can be built, homebuilders will sometimes bring in loose soil from another location, using it to fill in hollow, depressed areas.

These recently excavated “fill” soils are fluffed and will be much looser and lighter than the denser, hard-packed virgin soils already present.

If the soil isn’t properly compacted, it can compress underneath the foundation and cause your structure to settle.  

To compensate, the builder will need to compact the fill soil thoroughly before placing a foundation on top. If this compaction is not done or is improperly done, then the weight of your home may cause the soil to compress, leading to foundation settlement issues.

Weak Bearing Soil

When the soil is incapable of carrying the pressure or weight of a building’s foundation, the footing may begin to sink into the soft soil.

Fortunately, footings can be redesigned to balance the load over weak soil, which will reduce the likelihood of foundation settlement.

Because footings are designed to meet general guidelines rather than a specific type of soil, most settlement issues stem from the weak bearing soil underneath residential buildings.

Moisture Content Changes

Moisture content in foundation soil can change. For example, if too much moisture soaks through foundation soil, this can cause the softening or weakening of clay silt, reducing the soils’ ability to support the load and typically results in foundation settlement. 

Soil with high clay content can Shrink with Loss of Moisture

When clay soil dries out, they shrink or contract, reducing the general soil volume. This results in foundation settlement damage. Settlement damage can also occur when a structure is supported by dried-out soil.

When foundation soil dries out, it is usually due to conditions from lack of rain or extensive drought, maturing trees, vegetation, or leaking subfloor HVAC systems.

Soil Consolidation

When a structure’s weight or newly placed fill soil compress lower, weakened clay soils – weakened clay soils, soil consolidation occurs.

The load then forces the water out of the clay soil, densely spacing out individual soil particles.

Consolidation causes settlement of overlying structures and downward movement of the foundation – often at an uneven level, creating structural damage and/or cracks.     

So Long to Soil Settlement Damage   

Foundation repair specialists are best equipped to repair foundation settlement damage.

If you encounter any of the symptoms listed above, it’s smart to get in touch with a foundation repair specialist here at Dalinghaus Construction, Inc.

Unlike other general contractors who are likely to suggest demolishing and then reconstructing damaged masonry, a foundation repair contractor has the ability to raise settled foundations.

This impedes foundation settlement and closes settlement cracks without demolishing walls and slabs.

Nondestructive repairs are faster, less disruptive, and less expensive than destructive repair.

If you live in Southern California or Central Arizona and want a FREE foundation inspection, click the link below –

WRITTEN BY

Brian Dalinghaus

Brian is one of the Co-Founders of Dalinghaus Construction. He has been in the foundation repair industry since 2005. During his career, he has been associated with helping over 4,000 homes and structures throughout California and Arizona.

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