When you need a deep foundation system for a new construction project, helical piers are the way to go. With a detailed geotechnical report, helical piers can be designed to provide the support you need to keep your new structure from settling. They can be quickly installed at any time during the year and are a cost-effective alternative to traditional concrete piers.

What are helical piers?

Helical piers (also called helical piles) are large, steel foundation pins that look something like screws. They’re mainly used for new construction projects requiring a deep foundation system due to soil conditions that are less than ideal. However, they’re sometimes used for lifting, leveling, and supporting existing foundations that have settled. Helical piers take the structure’s weight and transfer it to load-bearing soil.

Because helical piers for new construction (and repairing settled foundations) don’t require heavy excavation, installation is quick and causes minimal disruption. They’re turned into the soil via a helical drive motor until they reach the depth and/or torque requirement specified by the geotechnical engineer. This depth could be anywhere from 10 to 30 feet below ground or even up to 150 feet deep, if necessary.

Helical piers come in many different sizes and configurations, so a detailed soils report is used to design the piers per the load requirements recommended by the geotechnical engineer. The diameter of the helices depends on the soil type, with clay soil requiring larger helices. Sometimes, depending on the soil conditions, piers with more than one helix might be necessary.

Other names for helical piers include helical piles, screw anchors, screw piles, screw piers, helical anchors, and ground anchors.

Benefits of helical piers

The advantages of helical piers include,

  • Quick installation.
  • Less excavation compared with other types of piers.
  • The piers can immediately begin bearing loads once they’re in place. In contrast, drilled concrete piers need time to cure.
  • A good solution for unstable soil or when there’s a high groundwater level.
  • The multiple bearing plates increase stability.
  • Suitable for environmentally sensitive areas.
  • They can be installed year-round.

Helical piers and foundation repair

Helical piers can be used to lift and stabilize foundations experiencing settlement. When the soil under a foundation isn’t stable – this can happen for a variety of reasons – it can, over time, cause the foundation to sink unevenly. When this happens, we say the structure has “differential settlement.” Since differential settlement can cause severe foundation damage, contractors sometimes use helical piers to lift and stabilize the foundation.

Signs of differential settlement include,

  • Uneven floors
  • Doors and windows that stick
  • Walls that have separated from the floor and/or ceiling
  • Floor cracks, especially ones that run wall-to-wall
  • Wall cracks, with or without bowing
  • Torn wallpaper (This might indicate a crack behind the wallpaper)
  • Diagonal cracks that run from the corners of doors and window up toward the ceiling
  • Rotated wall
  • Moldings that have separated from the wall and/or ceiling
  • Stairstep cracks in brickwork
  • Leaning chimneys or porches

For more information about settlement, see Foundation Settlement.

Foundation Settlement

Helical piers vs drilled concrete piers

For decades, drilled concrete piers were the go-to solution for new construction atop expansive soils (Expansive soils are those that easily absorb and release water). However, sometimes it’s challenging to install drilled concrete piers to the depth necessary to support a foundation properly. For various reasons, helical piers are a cost-effective and increasingly popular alternative for deep foundations built atop expansive soils.

How much do helical piers cost to install?

Since the cost of helical foundation piers is determined by the piers’ size, and the piers’ size is determined by what they need to support, we can’t give you even a ballpark figure. Of course, the cost will also depend on your geographical area.

For accurate helical piles cost information, contact a professional foundation repair contractor in your area. If you’re in our service area – we typically serve homeowners within a 75-mile radius of our office at 5170 Fulton Dr. Suite C, Fairfield, CA 94534 – contact us for a free inspection and estimate.

If you think your home has foundation damage

Foundation damage from settlement reduces your home’s value. Therefore, it’s important not to wait until a minor foundation issue turns into a big problem that will be even more expensive to fix. All homeowners should learn how to spot foundation problems early.

At Bay Area Underpinning, we take pride in providing you with the most cost-effective solutio