Why Foundations Shift and How To Prevent It

You may not give much thought to your home’s foundation until problems arise. A shifting foundation leads to a host of issues, from cracks that are purely cosmetic to severe structural damage. Understanding why foundations shift and how to prevent it helps maintain a safe and stable home. This article explores the causes of foundation shifts, signs to watch for, and preventative measures to protect your investment.

What Are Foundation Shifts?

Foundation shifts occur when a house’s foundation moves, typically sinking deeper into the ground. While you can expect some degree of settling, especially during the first few years after your home’s construction, excessive or uneven shifting spells trouble for a home’s structural integrity.

Types of Foundation Settlement

Foundation settlement shows up in different forms, each with unique characteristics. Immediate settlement takes place during the building’s initial week of construction. Structural engineers address it through careful monitoring and adjustments before completing construction. These adjustments allow builders to balance the foundation, preventing unintended shifts later in the building’s life.

Primary settlement, which occurs over one to five years, results from the underlying soil compacting as water squeezes out. This causes the foundation to sink as the soil becomes more compact. Managing the soil’s moisture levels minimizes the effects.

The third type, secondary settlement, is a long-term process that might continue over a property’s lifetime. It’s caused by perpetual stress on the soil from the weight of the structure and the external environment. Regular inspection and maintenance mitigate the impact of the stress. 

Uniform Vs. Differential Settlement

Foundation shifts are categorized as uniform or differential, each with different implications. Uniform settlement affects the entire home, causing it to sink evenly at a consistent depth and rate. This type of settlement may have subtle effects on utility and plumbing lines, but the consistency of the settlement minimizes structural damage.

Differential settlement presents more concerns. It happens when different parts of the home experience varying settlement rates, leading to unevenness in the foundation. This unevenness causes significant strain on the structure, leading to damage that compromises the building’s integrity. Address differential settlement promptly to avoid the need for extensive repairs.

What Causes Foundation Settling?

Foundation settling results from the complex interplay of multiple factors. Moisture levels in the soil play a role—too much moisture causes soil to expand and become unstable, while too little leads to shrinking and increased compaction.

Soil composition is another critical factor. Some soil types, such as those rich in clay or with significant peat content, expand and contract with moisture changes. Homes built on these soils need close attention to soil management practices.

Poor drainage can also cause water to pool and erode the soil supporting your foundation. The earth shifts, especially in homes perched on hillsides, where natural movement and erosion occur frequently. In addition, significant plumbing leaks can saturate the soil surrounding a home, making settlement problems worse.

How close trees and large plants are to your home’s foundation plays a role in causing it to shift. Tree roots draw moisture away from the soil, causing it to contract and destabilize your home’s foundation.

Signs Your Home’s Foundation Is Shifting

Detecting foundation issues early saves time and money, keeping minor problems from becoming significant structural concerns. Here are signs of foundation movement:

• Cracks in floors, foundation walls, or internal walls signal foundation distress.
• Doors and windows begin to stick or become difficult to open and close as frames shift out of alignment.
• Uneven or sloping floors indicate underlying foundation tilting.
• Bowed walls and cabinets separating from walls suggests increased internal stress on the structure.
• Diagonal cracks around windows and door frames point to differential settlement issues.
• Molding and baseboards separate from walls as parts of the house shift unevenly.
• Detached chimneys or porches indicate differential stress.

If you notice any of these signs, consult a foundation specialist to diagnose the problem.

How To Prevent Foundation Shifts

Take preventative measures right from the beginning of construction and throughout your home’s lifespan to safeguard against foundation shifts.

Proper Construction Practices

Building a home using sound construction practices is the first defense against foundation shifts. Working with structural engineers and soil specialists ensures your foundation is built on properly prepared soil, taking moisture levels and elevation into account. Experts analyze the soil to determine its bearing capacity and adjust construction plans accordingly to create a stable base for your house.

Maintain Proper Drainage

You need proper drainage to prevent water saturation and resulting foundation problems. Regularly inspect and repair gutters and downspouts to direct water away from the foundation. Consider installing yard drains or French drains to manage soil moisture levels. Grading the soil around the foundation creates a slope that directs rainwater away from your home, preventing pooling near the base.

Control Vegetation

Vegetation near your home impacts its stability. Choose trees and shrubs with non-invasive root systems and plant them a safe distance from the house. Regularly trimming and managing plants helps prevent roots from growing into the foundation. Choose plants that enhance your home’s surroundings without compromising its structural integrity.

Address Plumbing Issues Promptly

Address plumbing issues right away to help maintain a stable foundation. Regularly inspect plumbing fixtures, pipes, and external taps for leaks, which can cause soil saturation and erosion. A proactive approach reduces the risks to your foundation that plumbing problems can cause.

Waterproof Basements and Crawl Spaces

Waterproofing basements and crawl spaces protect foundations from moisture penetration. Install a sump pump in basements, especially in areas prone to flooding during heavy rains. Apply waterproof sealants to walls and floors as an extra moisture barrier. Proper ventilation in crawl spaces also reduces humidity levels.

When To Seek Professional Help

Contact a foundation specialist if you:

• Notice large cracks (over ¼ inch wide) appearing in walls or around the foundation.
• Have difficulty operating doors and windows
• Detect uneven floor surfaces
• Have persistent water buildup around your foundation after rainstorms

A professional will provide a customized solution, possibly installing foundation piers or helical piles to stabilize or lift the structure, performing mudjacking or slabjacking to level sunken slabs, or repairing and replacing damaged structural components.