Like push piers, pin piles are designed to transfer the weight of your home to load-bearing soil or bedrock, permanently stabilizing its foundation. Unlike push piers, however, pin piles are driven into the earth using a portable pneumatic hammer or a hydraulic hammer powered by a mini-excavator. This method can be an option in situations where there isn’t enough structural weight to drive a push pier and there isn’t enough space to install a helical pier. They can also be used to stabilize sinking concrete slabs using a special slab pier bracket.
Installing a Pin Pile System
Using a pneumatic or hydraulic hammer, successive pile sections are driven into the soil until they can’t be driven any further. This is known as being driven “to refusal” and indicates that the piles have reached bedrock or load-bearing soil. Pile sections can be joined to each other by field welding or by using internal sleeved couplings.
When pin piles are used in new construction, steel reinforcement (rebar) can be inserted into holes that are drilled in the top of the pile, or a cap plate can be installed. In these applications, the piles are cast into the structural concrete of the new foundation, and the weight of the structure is transferred to stable soil at a greater depth.
The primary advantage of a pin pile system is that it stabilizes your home’s foundation permanently. In addition, the installation of a pin pile system can often be completed in a matter of days. Total foundation replacement, typically takes much longer, costs more and does nothing to address the issue that caused the problem in the first place: poor soil beneath the foundation.