Types of Piers

The two most common types of piers are push piers and helical piers. The choice between them depends on the weight of the structure and the specific soil conditions.

• Push Piers: These are steel tubes that are hydraulically driven into the ground using the weight of the building as resistance. They are typically used for heavier structures, as the building’s weight is essential for pushing the piers to a stable depth.
• Helical Piers: Resembling giant screws, these steel shafts have helix-shaped plates welded to them. They are twisted or screwed into the ground using a hydraulic torque motor. Helical piers are ideal for lighter structures, such as decks, porches, or single-story homes, because they do not rely on the weight of the structure for installation.

The Installation Process

The installation process for both types of piers generally follows these steps:

1. Site Preparation: A professional will first excavate small holes around the foundation’s perimeter at specific intervals to expose the footing.
2. Pier Installation: The piers are then installed either by pushing them with hydraulic rams (push piers) or screwing them into the soil with a torque motor (helical piers). They are driven to a predetermined depth until they reach competent, load-bearing strata.
3. Lifting and Stabilization: Once all piers are in place, a bracket is attached to the foundation. Hydraulic jacks are then used to lift the foundation, which can help close existing cracks and re-level floors.
4. Final Steps: The piers are permanently locked into place using the brackets, and the excavated soil is backfilled to conceal the repair.

Visible Signs of Foundation Movement

These are the most common and easily identifiable clues that your foundation is failing.

• Cracks in Walls: Look for diagonal or stair-step cracks in your interior drywall, plaster, or exterior brickwork. These are often widest at the top and narrow at the bottom, indicating that one part of the foundation is sinking faster than another.
• Sticking Doors and Windows: If doors or windows no longer open or close smoothly, it’s a strong sign that their frames have become “out of square” due to foundation movement. You may also notice gaps around the frames.
• Uneven or Sloping Floors: If floors feel spongy, bouncy, or have a noticeable slope, it means the foundation is not level. A simple test is to place a ball on the floor to see if it rolls to one side of the room.
• Gaps: Look for gaps where walls meet ceilings or floors, or where a chimney or porch has pulled away from the main structure.

The Underlying Causes

Pier installation is used to correct foundation problems caused by specific soil conditions and environmental factors.

• Expansive Clay Soil: Many regions have clay-rich soil that expands when wet and shrinks when dry. This constant cycle of swelling and shrinking can push and pull on the foundation, causing it to crack and settle.
• Poor Soil Compaction: If the soil was not properly compacted before the home was built, it will compact over time, leading to foundation sinking.
• Poor Drainage: Inadequate grading or a lack of drainage systems can cause water to pool around the foundation. This can saturate the soil, leading to erosion or excessive hydrostatic pressure, which pushes on the foundation.
• Natural Disasters: Events like droughts, floods, or earthquakes can cause rapid and severe soil changes, which may lead to sudden foundation failure.

If you are noticing a combination of these signs, it’s important to contact a structural engineer or a professional foundation repair company. They can perform a thorough inspection to determine the cause and severity of the damage and recommend a professional pier installation if necessary. Delaying the repair can lead to more extensive and costly problems down the line.