The Homeowner’s Guide to Underpinning
We get it: fixing anything around your home can be challenging and stressful, and foundation repair is no exception. You have many options, including underpinning. You may have heard this term, but it can be a complex concept and repair technique.
Let this page be your guide to understanding foundation underpinning. By the end of the article, we want you to feel empowered to spot signs of home damage and know how they can be fixed with lasting foundation repair solutions. In this comprehensive guide, we explore what is underpinning, why it might be necessary, and how Groundworks’ proven house underpinning solutions protect your home for generations to come.
What Does Underpinning Mean?
Underpinning plays a vital role in protecting your home’s structural integrity. But exactly what is underpinning?
Simply put, it’s a construction technique used to strengthen and stabilize an existing foundation by extending it to more supportive soils or bedrock.
Different types of foundation piers provide this permanent stability by bypassing weak soils and anchoring onto more reliable earth deep beneath your home.
Related Resource: 5 Things to Know About Foundation Piers
When is Underpinning Foundation Repair Necessary?
House underpinning becomes necessary when the original foundation is compromised or needs additional support. This can happen due to many factors, including:
- Expansive Soil: Particularly clay-rich soils undergo dramatic volume changes based on moisture content, alternately pushing up and shrinking away from the foundation. This continuous cycle of expansion and contraction can cause severe foundation movement and structural damage.
- Soil Erosion or Settlement: Causes soil beneath the foundation to wash away or compress over time, creating voids and uneven support. This process is often accelerated by poor drainage or underground water movement, leading to foundation instability.
- Poor Soil Preparation: During construction, builders sometimes fail to properly compact the soil or remove organic material before laying the foundation. The resulting unstable base can lead to future settlement issues as the decomposition and compression of unsuitable materials continue.
- Invasive Tree Roots: Can grow under and around foundations, causing soil displacement and moisture content changes in the surrounding area. As roots expand and contract seasonally, they can create voids and pressure points that destabilize the foundation.
- New Floor Additions: Increases the load on an existing foundation beyond its original design capacity, particularly in older homes. The additional weight stresses the foundation, requiring reinforcement through underpinning to prevent structural failure.
- Nearby Excavation: Can destabilize the soil supporting adjacent foundations by altering underground water patterns and soil stability. Construction activities like deep basement excavations or utility trenching can create soil movement that compromises nearby foundation integrity.
- Foundation Damage or Deterioration: Occurs through water infiltration, freeze-thaw cycles, or poor initial construction practices that weaken the concrete and reinforcement materials. These issues compound over time, eventually requiring structural intervention to maintain building stability.
Effective Foundation Underpinning Methods
Underpinning a house takes many forms. However, these repair methods are not created equal.
Some traditional underpinning foundation techniques—including concrete underpinning, concrete or steel concentric piers, and square or round shaft helicals—simply cannot withstand the structure’s weight and problematic soils, and ultimately fail over time.
At Groundworks, we care about your safety and creating a stable living environment for your family. We install house underpinning solutions tested and proven to permanently stabilize your home’s foundation. We offer three types of foundation piers for underpinning repair:
1. Helical Piers
No matter what type of house you have, our helical pier system provides exceptional stability for both light and heavy structures. These steel piers feature helical plates that screw into the ground like a giant corkscrew, reaching stable soil layers deep beneath your home. They’re ideal for:
- Lighter structures like porches and additions
- Areas with varying soil conditions
- Projects requiring minimal excavation
- Sites with limited access
2. Push Piers
Push piers, commonly known as resistance piers, are our go-to solution for heavier structures requiring significant support. These straight steel piers are hydraulically driven into the ground until they reach bedrock or competent soil. Benefits include:
- Maximum stability for heavy structures
- Potential foundation lifting capabilities
- Minimal site disruption
- Fast installation process
- Immediate support after installation
3. Slab Piers
Specifically designed for concrete slab foundations, our slab pier system addresses settlement issues in slab-on-grade homes. These specialized piers:
- Stabilize settling concrete slabs
- Provide an opportunity for slab lifting
- Require minimal interior disruption
- Offer a permanent solution to slab settlement
- Can be installed in tight spaces
A Look At Our Trusted Underpinning Process
Since we install three types of house underpinning, each process looks slightly different. For example, we attach a bracket to the foundation footing to allow for the easy installation of push piers; but this bracket is added after helical piers are placed in the ground.
You can learn more about how each system is installed by visiting the solution pages linked in the previous section.
While individual installations may vary, all our underpinning repair solutions have the same goal: to permanently stabilize your foundation and potentially lift settling sections.
Here is a general overview of the underpinning foundation process:
1. Initial Assessment
- Structural evaluation
- Soil testing
- Foundation inspection
2. Planning Phase
- Underpinning repair method selection
- Design development
- Permit acquisition
3. Implementation
- Site preparation
- Sectional excavation
- Installation of new support
- Quality testing
4. Completion
- Benchmarking
- Site restoration
- Final inspection
- Documentation
Signs You Need Foundation Underpinning
Foundation damage appears as various symptoms. These eight common signs indicate you may need house underpinning:
- Foundation wall cracks
- Floor cracks
- Cracks in drywall
- Doors and windows that stick or won’t close properly
- Sloping or uneven floors
- Separation between the walls and floor or ceiling
- Cracking and tilting chimney
- Foundation settlement or sinking
How Much Does Underpinning A House Cost?
When homeowners face foundation issues requiring underpinning, providing a one-size-fits-all cost answer is impossible due to the many variables involved.
The extent of foundation damage, soil conditions, and foundation type all play crucial roles in determining the final cost. For example, minor settlement in one area requires far less extensive work than multiple points of failure, while soil conditions can dictate the depth and complexity of the required solution.
The type of foundation itself shapes the approach needed, with different methods required for slab, basement, or crawl space structures. Additional factors affecting cost include necessary supplementary repairs such as drainage improvements, waterproofing systems, and fixing interior damage caused by foundation movement.
To understand potential costs for your specific situation, have a foundation repair professional like Groundworks conduct a thorough evaluation to assess all contributing factors and recommend appropriate solutions based on your home’s unique circumstances.
Groundworks Provides Lasting Underpinning Solutions
Underpinning is an investment, but it provides numerous benefits, including preserving your home’s value and structural integrity. To get the most out of your underpinning repairs, work with trusted qualified professionals like Groundworks to assess your home and recommend appropriate underpinning repairs tailored to your needs.
Don’t wait until minor foundation issues become major structural problems. Contact Groundworks today for a free inspection and learn how our proven underpinning solutions protect your most valuable investment. Our team of experts is ready to help restore your home’s stability and your peace of mind.
Underpinning Repair FAQs
The duration of house underpinning varies based on the project scope, but our efficient crews typically install underpinning repair solutions for residential properties within a few days to a week.
While possible, temporary relocation is often recommended due to noise, dust, and potential safety concerns. Your inspector will review the underpinning repair process based on your home’s needs.
Coverage varies by policy. Some homeowner’s insurance plans cover house underpinning if the damage was caused by covered perils, but many consider it a maintenance issue. Check with your provider for your policy’s specific details.
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