What’s green, hard as steel and lasts 100 years or more?

It's not your aunt's fruit cake, but it has been used to build hundreds of lighthouses

By Murphy Bros. Project Mgr. Drew Johnston and Marketing Director Tom Myrick

 

Helical Pier foundations are a growing trend in building that could save you time and money.

Whether you are building a pyramid in Egypt or a deck off your second story patio door, a solid foundation is critical.  And in most residential cases, that foundation has been made of concrete. However, in the past decade or so builders have been rediscovering a method that dates back more than 100 years.  Although more commonly used in commercial construction, helical piers are becoming more and more utilized in residential building and remodeling. 

 

Murphy Bros. crews installing helical piers to create a stronger, more lasting foundation.

Helical piers, also referred to as helical piles or screw piles, were developed to structurally support offshore foundations such as lighthouses in the 1800's and were modified over time for inland use.  They are essentially large earth screws made of galvanized steel, can be a bit more expensive than traditional poured footings but with the logistics, hours and lag time that accompany traditional concrete footings, helical piers may be a solution for many jobs moving forward. When all is said and done, in some instances, they can actually reduce costs.

 

Finished Porch with multi-level stairs

Centering pier before adding next length of galvanized shaft.

How it works

Helical piers are used primarily in areas with unstable or variable soil conditions. They are able to get below the topsoil and reach stable ground to provide a solid foundation.

The piers are installed with a skid loader or a walk-behind unit, depending on the project accessibility and size/depth of the piers, with a special attachment to torque the pier to depth.

As seen above, piers are installed at 5’ increments, with the first length being the spiral cutting blades. Each following length is attached to the shaft with through bolts. The pier is installed until a required torque is registered. The required torque is predetermined by the soil condition and the load requirements for the project. The torque reading and corresponding kip measurement is produced in a printout that is then sent to the city officials for footing inspection.

 

Welding base plate to pier.

Advantages of using helical piers vs. concrete footings

  • Helical piers have little to no down time and can be installed in any weather.
  • Increased footing stability to help prevent uplift from frost in the winter and from movement caused by settling in the summer.
  • Fast installation with immediate loading.
  • There is no need to have a footing inspection to verify footing size/depth and they can be built on almost immediately.
  • No waiting for concrete to cure.
  • Environmentally friendly (green).
  • Helicals can be relocated. If the pier is installed and the plans are modified or pier is installed in the wrong location, a pier can be removed and installed at a new location. Concrete footings would need to be discarded or abandoned
  • Can be easily modified in the field.
  • Piers don’t require huge spaces for site access since they can be installed with a mini-excavator or skid-steer.
  • Compared to concrete installation is extremely fast, shaving days or even a week off the construction schedule.
  • It is easier to work around existing landscaping or older stone foundations and in areas where access is limited.
  • Depending on soil types they can last hundreds of years.
  • Can be a good solution for repairing old foundations and pilings.
  • No removal/relocation of soil needed with helical piers.

 

Post base is applied to the support post then base is welded to the attachment plate. After weld the excess 12” x 12” plate is trimmed off.

Final trimmed support post with helical pier.

In the Twin Cities, most communities have homes built in areas with high water tables or expansive soils, and it is becoming more common for professionals in the industry to recommend helical piers over concrete.


Talk to us

Call (763) 780-3262 or talk with a professional remodeler about your project.

Schedule a Consultation