Helical anchors, also known as screw anchors, are commonly used for underpinning and settlement arrestment, but screw anchors can also be used for tiebacks, uplift anchors, and new construction piles. The pile is built by screwing the anchor into suitable load-bearing soil.
The pile capacity is determined by the installation torque obtained during installation. Helical anchors are available in various shaft sizes and helix configurations, providing a wide range of options for meeting the required specifications.
Helical anchors or screw anchors will be used to complete your foundation stabilization project if you secure a new foundation or repair an existing one.
What is a Helical Anchor?
A helical anchor, also popularly known as a screw pile, screw anchor, or helical pile, is an adjustable foundation system of helically shaped steel plates connected to a central shaft with a round or square shape cross-section. The thickness, number, diameter, and position of the steel plates are determined by the minimum design life of the restrictive or supporting structure, the environmental corrosion and geotechnical specifications, and the various loading requirements.
Helical anchors or screw anchors are installed into the ground by twisting them with hydraulic rotary attachments connected to earth-moving equipment. Hence, they do not necessarily require extensive excavation. Once the plates have reached a suitable depth, they provide significant pull-out resistance. They then transmit the load from the steel shaft to the soil.
Helical Anchor Installation Process
An inspection is the first step in any foundation repair project. A qualified foundation stabilization professional locates and diagnoses foundation failure signs and symptoms.
- Chimneys that are leaning.
- Slanted Floors
- Cracks in the drywall
- Sticky Windows and Doors
A thorough inspection examines the interior and exterior of the home, as well as the foundation itself whether it is a slab on grade, post-tensioned, or raised.
PREP WORK BEFORE INSTALLING THE SCREW ANCHORS
The foundation must be prepared before the Helical screw anchors can be hydraulically driven into the earth to reach competent, load-bearing soil. Helical screw anchors can be used on a variety of foundations, including:
- Slab ground foundations.
- Slab with post-tensioning foundation.
- Raised Foundations.
The Helical Pier locations must be dug up irrespective of the type of foundation. Helical screw anchors are used every 6 feet, and their positions are marked with painter’s tape to avoid permanently damaging the home’s stucco/siding. Foot pits are typically dug 18 to 24 inches deep at delineated locations to access the foundation’s footing. In some cases, concrete removal and substituting are required to obtain access.
Following the excavation of the holes beneath the footing, the foundation stabilization expert crew uses a demo hammer to level the footing, getting it ready for the remedial bracket to accommodate an L shape to the ground. The remedial bracket is then attached to the footing after this.
INSTALLATION OF SCREW ANCHORS
Helical Piers, or screw anchors used for foundation stabilization in the United States, are screwed into the ground rather than pushed into it.
The Helical Piers are screwed into capable, load-bearing soil. Helical piers are created by applying extreme torque to a torque motor secured to a torque bar.
STABILIZATION / LIFTING PROCESS
The lifting process can begin once all of the helical screw anchors have been safely installed at each location. All foundation repair specialists strive for maximum practical recovery. The extent of lift that can be securely achieved without jeopardizing the structural (and, in some cases, cosmetic) integrity of the home is known as Maximum Practical Recovery.
Not all homes are lifted because of structural and cosmetic concerns; however, homes equipped with screw anchors are presumed stabilized because they will not sink any further.
Screw anchors support structures, especially when the ground conditions are hard to prepare for a standard base system. The setup is subtle but effective. Finally, the success of this installation is based on the helical screw anchor’s potential to sustain the base, which is directly measurable.
Take a look at this video to learn more – What It Looks Like After Helical Piers Are Installed.
Benefits of Helical Anchors and Screw Anchors
The main benefits of helical screw anchors are their quick installation and potential to load the pile right away. You can resume work immediately because there is no need to wait for the sealant to heal.
Another advantage is that foundation stabilization experts can install helical screw anchors with relatively small equipment and in areas with limited access. Furthermore, there are no spoils from the installed pile, making the installation process extremely clean compared to other pile types.
Helical anchors, too, have drawbacks. They cannot, for example, be installed into or through rock. In addition, lateral stability or buckling may be an issue in certain soil conditions.
When Should Helical Anchors or Screw Anchors be Used?
According to foundation stabilization specialists, helical piers or screw anchors are required for various residential and commercial applications but could be used when the task calls for caissons, driven piles, or mini piles.
Structure and foundation damage becomes noticeable when foundations are subjected to moisture for an extended period or when construction is done on unstable ground. They are used to stabilize the foundation of your property to fix the foundations and guarantee that the building does not decrease in value. When foundation failure is detected, helical piers and piles could be used to repair the foundation:
- Windows and doors are jammed and difficult to open.
- There are significant gaps in the window and door frames.
- The interior plaster walls are beginning to crack.
- There are numerous nail pops in the ceilings and walls.
- The walls are starting to sag noticeably.
- The floors are settling and becoming uneven.
- Chimneys are leaning or wobbling.
- Cracks can be seen in basement walls or foundations.
WHAT CAUSES FOUNDATION CRACKS?
Foundation cracks can be caused by one or more of the following factors:
Large volumes of water around the foundation due to heavy rains, melting snow, plumbing leaks, improperly installed gutters, and poor drainage. Soil expansion and contraction caused by seasonal rain and drought cycles, soil type, and inadequate soil preparation before construction. The settlement caused by large tree root systems underneath and near the foundation, or soil settling caused by poor preparation
WHAT IS THE DIFFERENCE BETWEEN HELICAL ANCHORS, HELICAL PILES, AND HELICAL PIERS?
Helical anchors are steel shafts wielded with helical bearing plates that can be extended. Piles and piers are deep foundation elements that can withstand or transfer vertical/horizontal loads. Anchors are only used in uplift/tension software, such as restraining wall tiebacks or vertical ground anchors and are designed to withstand overturning forces.
Keep in mind that tension forces pull materials apart, whereas compression forces squeeze materials together. As a result, piles are typically made of steel, wood, and other materials that can be thin and do not use concrete in their construction. On the other hand, piers are made entirely of concrete and are large in diameter.
Helical anchors, installed vertically or horizontally, are used in tension/uplift applications. Horizontally, they are commonly used underneath retaining walls and are known as tiebacks. Anchor piles, base anchors, ground anchors, ground anchors, or soil anchors are the names given to them vertically.
DOES ALL SETTLING AFFECT THE FOUNDATION?
Not all settling points to a foundation issue. New homes frequently settle into the soil beneath them for a few years after being built; this does not affect the foundation’s stability. Settlement in small increments is average and does not necessitate contacting us.
However, if the settling appears excessive or accompanied by visible damage to the foundation or your walls, doors, and chimney, please contact foundation repair experts. The sooner you act, the minor damage your foundation will sustain and the less harm will be done to your most valuable asset, your home.
EVEN AFTER THE CRACKS IN THE CONCRETE SLAB FOUNDATION ARE REPAIRED, IT CONTINUES TO CRACK. HOW CAN THIS ISSUE BE PERMANENTLY RESOLVED?
A cosmetic solution mending cracks with mortar is insufficient if cracks continue to appear. This is because the ground beneath the slab may not support the weight of the slab and the structure it supports. Poor or faulty drainage around the slab, on the other hand, may have washed soil away beneath a section of the slab.
Another possible cause is expansive soil. But, again, a skilled foundation repair specialist like HydroHelp911 can assess the foundation, test the soil, and determine what repairs are required to stabilize the foundation.
WHEN ARE HELICAL PILES USED?
When compared to traditional foundation systems, helical piles have several advantages:
- Does not necessitate excavation.
- Easy installation.
- Least amount of disruption.
- It is ready to use right away.
- It is simple to use, even in remote areas.