Irving Foundation Repair Pros connects homeowners and property owners looking at drilled bell-bottom piers in Irving, TX with an independent local foundation company that builds them.
A bell-bottom pier is a drilled concrete pier with a wide base, shaped like an upside-down bell. Instead of pushing something into the ground, the crew drills a shaft, flares out the bottom, sets steel reinforcement and fills it with concrete. Once the concrete cures, the house is lifted on it.
How They Are Built
- A shaft is drilled beside or under the foundation beam.
- A special tool widens the bottom of the shaft into a bell shape.
- Rebar is set in the shaft, and concrete is poured.
- The concrete cures, which can take days to weeks depending on the mix and the engineer's specification.
- The foundation is lifted on the cured piers and shimmed.
Why Some Engineers Prefer Them
The wide base spreads the load over more soil and resists being pulled upward when expansive clay swells. That makes drilled bell-bottom piers a common choice in specifications written by engineers in North Texas, particularly for larger houses and commercial buildings.
Trade-Offs
- Time: curing adds days to the job compared with pressed piers.
- Equipment: drilling rigs need room, which can be hard in tight side yards.
- Cost: drilled piers usually cost more per pier than pressed concrete piers.
- Soil: drilling in wet or caving soil may need extra steps.
What to Ask
- What diameter and depth are the shafts, and how wide is the bell?
- Is the design from an engineer, and will I get the drawings?
- How long will the concrete cure before lifting?
- How will drilling equipment reach the back of the house?
- What does the written warranty cover?
Bell-Bottom Piers vs Steel Piers
Both reach deeper than pressed concrete piers. Steel piers are driven to resistance and give an installation pressure for each pier. Bell-bottom piers rely on the size of the bell and the soil around it. See steel pier foundation repair for comparison.
A Typical Installation Day
A truck-mounted or track-mounted drill bores each shaft beside the beam, and a belling tool cuts the wider base at the bottom. A crew checks each hole, sets a steel reinforcing cage, and fills the shaft with concrete. The house is not lifted that day. Crews let the concrete cure before they jack against it, so drilled-pier jobs take longer than pressed-pier jobs from start to finish. Expect spoil piles in the yard until the crew hauls them off, and ask in advance how they will protect sprinkler lines, fences and beds along the work area.
Common questions
Why do bell-bottom piers take longer?
The concrete has to cure before it can carry the house. That waiting time is built into the schedule.
Are bell-bottom piers worth the extra cost?
For some houses and soil conditions, especially where an engineer specifies them, yes. For many smaller houses, other pier types work well. Ask why the contractor recommends them.
Can bell-bottom piers be installed inside the house?
Interior drilled piers are possible but harder because of equipment access. Many plans use drilled piers on the perimeter and another method inside.
Do bell-bottom piers need an engineer?
They are often specified by an engineer, especially on larger houses and commercial buildings, because the diameter, depth and reinforcement are designed. Ask whether the plan comes from an engineer and whether you will get the drawings.
What happens to the dirt from drilling?
Drilling brings up a lot of soil. Ask whether it will be hauled away or spread on site, and how the crew will protect your lawn and landscaping.