The cracks in the basement wall are getting bigger. The back door is getting harder and harder to close. Clearly, it’s time to address your sinking foundation. Before you hire a contractor, know your options so that you can make an informed choice.

There are generally two options for leveling a sinking foundation, push piers and helical piers. While either can be an excellent choice, the differences between them can be important. Knowing the differences will help you to understand why your contractor wants one or the other.

A push pier is a series of hollow tubes that is fitted together and pushed down with a hydraulic ram until it reaches soil dense enough to support the load. Then the pier is attached to the structure with pier brackets. The weight of the structure provides the resistance that keeps these piers in place. Push piers work well in tight spaces, and for heavy structures that “push” them into the ground.

If a push pier is like a nail, a helical pier is like a screw, and a hydraulic motor turns it into the ground. As the pier is pulled through the soil to a dense layer, the surrounding soil pulls the pier into place. Unlike push piers, helical piers can go into the ground at an angle. If a structure has bowing walls, this can be essential.

Helical piers are generally preferred for residential projects, for a number of reasons. First, helical piers do not require a heavy load for resistance like push piers, which makes them better for smaller, lighter structures like garages or single-story homes. Second, as noted above, helical piers can be inserted at an angle, which may be necessary in some foundation repairs. Helical piers also provide flexibility, because they can be relocated. If you want to put an addition on your house, the existing helical piers could be moved and redistributed to support the new structure, while push piers are permanent wherever they have been placed.

Understanding the difference between push piers and helical piers will help you to understand your contractor’s choice, and feel confident about you