“What Is A Push Pier, And How Is It Installed?”
Well, I can definitely answer this one, considering repairing foundations is what we do every day.
The push piers we use here at Dalinghaus Construction are made of steel. Unlike some others, it’s hot dipped galvanized, which protects the pier from erosion. Imagine if you spent thousands of dollars on piers to repair your foundation only to later have them erode and no longer sustain the weight of your home. Push piers are used to lift your home back to as close to level as it will allow, and stop further movement. They are also used to stabilize your home where there is no lifting involved.
A push pier is a permanent solution for your homes settlement issues. It is an approved method by engineers. The push piers are hydraulically driven deep into the soil to bedrock or earth bearing stratum. The piers and their extensions are 30 inches (2 1/2 feet) each. They are commonly installed on the exterior of your home. Sometimes, certain conditions require us to install in the interior, it’s very rare. A few examples of those conditions are if we don’t have access from the outside, or there is equipment such as pool pumps or Air-conditioning units that you don’t want moved.
“How is this done? What is the process, and is it invasive?”
Well, we first excavate a 3 x 3 square foot area of soil to expose the concrete footing where the pier is to be installed. If the pier is being installed where there is concrete (like maybe a patio next to the house) we would saw cut a 3×3 square to expose the concrete footing.
We would later replace the concrete (We call this Concrete Removal & Replacement). You can stay in your home during this process. There is no large or heavy equipment used. The equipment we use (depending are your project) would typically include the hydraulic ram, a generator, a jackhammer/tamper, and miscellaneous hand tools.
Next step would be to mount the bracket below and against the footing. The brackets are also made of heavy duty steel. The piers are hydraulically driven through the bracket to bedrock or a stable soil layer. The depth they are driven varies depending on the soil. The piers are driven on average about 25 feet.
The piers are driven into the soil with a hydraulic ram. It’s a portable piece of equipment with the capabilities of driving the pier 10,000 psi. (PSI definition: Pounds per Square Inch- PSI is a unit of pressure expressed in pounds of force per square inch of area.)
It is a slow process. If you think about it… your home has settled over a period of time… and we’re going in and lifting it to maximum practical recovery in a matter of minutes. This process is documented by the foreman working on your home. These documents are called Pier Logs. The foreman records how deep the piers went, and how many PSI it took achieve the desired lift.
“How do they know they lifted to as close to level as they can get it?”
Prior to the installation, the manometer reading that was done at the initial inspection was given to the production foreman so he knows how much of a lift they need to achieve. During the lift, the foreman monitors the lift closely and will take another manometer reading during and after, that will tell him the amount of lift he has achieved.
After lifting the home to maximum practical recovery, there will be a void under the home left. This void will be filled with a Polyurethane Foam. Depending on how much of a void was left, typically it goes in about ten feet. This polyurethane is used to give the support the foundation needs and to keep the little critters out.
Once the pier is installed and the lift is complete, the area can be backfilled and the concrete replaced if needed.