The hybrid transition pier is a relatively new pier concept that is quickly becoming one of the most popular types of piers to install as it offers perfect balance between affordability and longevity for homeowners who plan on owning their house for a long time.
This hybrid transition pier is essentially the same in concept to a concrete pressed piling and a steel pier, using the same materials as well. The bottom of this pier is our steel pier and the top of the pier is our concrete pier. What this does is allow us to reach the depths that steel can reach, but eliminates a bulk of the cost by transitioning to concrete for the top.
How are they installed?
First a hole must be excavated near a beam of the foundation. For most projects these holes are dug around the perimeter of the foundation from outside of the house, however sometimes they need to be installed inside the house. This hole is approximately 30 inches wide by 30 inches long and the depth is about 24 inches below the bottom of the foundation, which could end up making the hole 48 to 54 inches deep. We also need to excavate 6 to 10 inches under the house to allow us access directly below the bottom of the slab. We then can start pushing pipe.
You use a hydraulic press to push these pipes into the ground one by one, interlocking each piece to help keep it aligned. We then place a transition piece on top of the pipe that allows us to connect a steel pipe to a concrete cylinder and resume pushing cylinders. The pier is then pushed to refusal, which for most of this area is when the bottom of the steel pier is able to sit on something hard, like bedrock or limestone.
Once this point of refusal is met for all the piers we are installing, we place the top cap on top of the last cylinder and place a 20 to 30 ton bottle jack to the right or left side of the top of the cap. The heavy duty bottle jack can then lift the house back into place. We then replace the bottle jacks with various assorted concrete blocks to shim up to the bottom of the slab with the last shim being a steel shim to help secure the pier to the house.
Most people choose the hybrid transition pier in situations where they plan on owning the home for a very long time and would rather not have to deal with as many warranty issues over it's lifetime. Since it is able to reduce that friction build up and sit the pier on something more solid than clay it will last a very long time. We also are able to more closely price this pier to that of a concrete pressed piling which is the most affordable option, compared to that of a pure steel pier.
There is very little drawback to using this pier, the only one that comes to mind is that it's slightly more expensive than a concrete pressed piling. However, when you compare this pier to a steel pier it's extremely more affordable.