The short answer
Assessing the Foundation
Before any digging begins, a structural engineer or a qualified foundation specialist inspects your home. They look for cracks, uneven floors, and signs of movement. The goal is to understand why the foundation is failing, whether from soil shrinkage, poor compaction, or water damage.
The assessment includes soil testing to determine load-bearing capacity. This data tells the pro how deep the new footings must go. In areas with expansive clay soils, seasonal moisture changes can cause shifting. That is why a thorough evaluation matters before any underpinning work starts.
Excavating in Sections
Underpinning is never done all at once. Excavating the entire foundation at once would destabilize your home. Instead, pros work in small segments, typically 3 to 4 feet wide. They dig beneath the existing footing one section at a time, ensuring the structure remains supported throughout.
Each section is excavated to the depth determined by the soil test. The pro then pours new concrete into the void, creating a deeper, stronger footing. Once the concrete cures, they move to the next section. This methodical approach prevents further settlement and keeps your home safe during the process.
The number of sections depends on the size of your foundation and the extent of the damage. A small home might need a dozen sections; a larger one could require many more. The pro will explain the plan before starting, so you know what to expect.
- Small sections protect structural integrity
- Concrete is poured to match existing footing
- Each section must cure before moving on
- Soil conditions dictate the depth needed
- Water damage may require drying first
Matching New Concrete to Old
New concrete must bond properly with the existing foundation. Pros clean the old surface and use a bonding agent before pouring. This ensures the new footing acts as one continuous support, not a separate piece that could shift.
The concrete mix is chosen based on the soil and load requirements. A stronger mix may be used for deeper footings. Pros also add reinforcement steel, known as rebar, to increase tensile strength. This helps the footing resist future movement from soil expansion or contraction.
Curing time is critical. Concrete needs days to reach full strength. Pros protect the new sections from rain and foot traffic during this period. In rainy seasons, timing the work to avoid heavy rain is part of the planning.
Handling Water Issues
Water is a common cause of foundation problems. If the soil under your home is saturated, it can lose bearing capacity. Pros often address drainage before underpinning. They may recommend gutter extensions, grading, or a French drain to redirect water away from the foundation.
If water has already damaged the soil, the pro might need to dry it out first. Structural drying equipment can remove excess moisture from the soil and the foundation. This step ensures the new concrete bonds to a stable base, not a muddy one.
Underpinning alone does not fix drainage. Without correcting the water source, the problem can return. A good pro will point out any obvious water issues and suggest solutions, even if those are handled separately.
- Drainage improvements prevent future settling
- Structural drying may be needed before underpinning
- Gutters and downspouts should direct water away
- Grading around the foundation helps runoff
- Moisture mapping can identify wet spots
Monitoring and Finishing
After underpinning, pros monitor the foundation for any signs of movement. They may install pins or marks to measure future shifts. This helps confirm the new footings are holding the structure steady.
The final step is backfilling the excavated areas and restoring the surrounding soil. Pros compact the soil to prevent future settling. Any cracks in your foundation are often patched as part of the process, though cosmetic repairs may be separate.
It is important to remember that underpinning is a major structural repair. It is not a quick fix. The process can take weeks, depending on the size of your home. Your insurance company may be involved if water damage caused the issue. Policies vary, and your insurer decides what is covered.
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Call Now (817) 799-6732Frequently asked questions
How long does underpinning take?
The timeline depends on the size of your foundation and how many sections need work. A typical job can take several weeks, including curing time. Your pro will give you a schedule before starting. Weather can also affect the timeline, especially in rainy seasons.
Can underpinning fix all foundation cracks?
Underpinning addresses the cause of movement by making the footing deeper. It can stop further settling and may close some cracks. However, existing cracks often need separate repair, such as epoxy injection or patching. A structural inspection will tell you what is needed.
Is underpinning the same as foundation stabilization?
Underpinning is one type of stabilization. Stabilization can also involve soil injection or helical piers, depending on the soil condition. A pro will recommend the right method after assessing your foundation. Both aim to stop movement, but the approach varies.