Through a little research, you realize that there are different techniques and methods of foundation repair out there. The term “pressed piles” or “concrete pilings” or “concrete pressed piles” has come across your screen, but *what exactly are* these things? You’re not an engineer so most of this stuff means absolutely nothing to you.
At Anchor Foundation Repair, we have been repairing foundations in Central Texas for 35+ years. We know that the everyday homeowner doesn’t have any reason to know this stuff . . . until they do because of foundation settlement and problems.
Instead of “talking industry lingo” at you, we want to make sure you are informed and confident about your foundation repair choices and can explain pressed piles to you for sure. We will review what pressed pilings are, what they are made of, and how they are installed. Then we discuss their pros and cons.
*Honesty Alert* We don’t do concrete pressed piles, we actually employ another method using drilled bell-bottom piers. We believe that no one method is *THE ONE* for all cases. Each homeowner has to decide what is most important and best for them in choosing the foundation repair method that will meet their needs.
Choosing what’s best for your situation all starts with education and understanding what is available to you. So, let the schooling begin . . .
What Is The Same About All Foundation Repair Methods?
All foundation repair methods have some basic similarities. All methods use a vertical support structure in the ground to lift, level, and hold the home in place. Engineers would call this “underpinning” and either piles or piers are used to provide this vertical support under the home.
Piles or piers can be made out of concrete, steel, or some combination of the two. But the ones we are talking about today are the ones just made out of concrete.
Piers in foundation repair are not the kind of pier that you fish off of near a body of water. Piles are not the kind made out of dirty laundry waiting to be washed. Instead, think of a beach house that is up on “stilts” raised above the ground to keep it away from water that might come ashore.
Now picture pushing that home down, those stilts being sunken underground, and the home resting on top of them and the soil. Each pier or piling invisibly helps to support the weight of the home from underground and keep it level. Generally, the number of piers or piles needed to support any given foundation repair scenario will be about the same for any method.
So to sum things up, all methods will use a vertical underpinning system that goes into the ground under the home. Any method will use approximately the same number of supports to complete the repair.
What’s different about the methods is how the “stilt” is made (or what it is made from), installed, and how it works to keep your home stable. We will go over these differences in the next section.
Concrete Pressed Pile Method Overview
Luckily, once I explain this method to you, the name will then make perfect sense. The pressed pile construction sounds exactly like what it is so it will be easy to remember after this section.
Construction of Concrete Pressed Piles
Pressed piles are made out of a bunch of concrete cylinders piled on top of each other and pushed underground. Each cylinder is 6” in diameter and 12” tall. We’ve got some pictures here for you to see what we are talking about.
The cylinders are a relatively inexpensive standard construction item made in advance that is brought to your home for use. They are topped with a pile cap, which is another piece of pre-made concrete shaped with a wider surface area on top.
Installation of a Concrete Pressed Pile System
A foundation repair crew will push the cylinders into the ground one by one using a hydraulic ram. They sometimes use the aid of hydropower to drive them further into the earth. The repair team would continue pressing more and more cylinders stacked on top of each other in a pile until they can’t anymore. They call this “the point of refusal,” as in the ground refuses to let any more of them get pressed in.
Is the name starting to make a little sense now? To put it the most plainly, it’s a pile of concrete cylinders pressed into the ground.
These concrete pressed piles will be placed at each needed support location and the pile cap placed on top, then the home is raised using jacks at each location and held in place with shims. This is a very basic description of the installation.
How Concrete Pressed Piles Work in the Ground
The pressed piles support the home through tension, kind of like a battery held into place with a spring on one end. In this case, the “spring” is the uplifting expansive clay soil below the piling pushing up against the weight of the house.
The Pros and Cons of Concrete Pressed Pilings
Now that you know what concrete pressed piles are and how they work in foundation repair, let’s explore their pros and cons. Every method of foundation repair has some good things and some not as good things about them. There is no one *perfect* method for all situations.
Pros Of The Pressed Pile System
The biggest benefits of the pressed pile method are lower cost and quicker installation time. It is understandable that some homeowners want or need the least expensive repair method possible. It is also reasonable to sometimes want things done as quickly as possible, and pressed piles might take just a couple of days to install.
If low cost or quick turnaround are your highest priorities, then the pressed pile pier method might be the best choice for you. These can certainly be the most important needs for some homeowners.
Cons Of The Pressed Pile System
The downside to choosing concrete pressed piles is that they are not as long-lasting for a couple of reasons outlined below.
Moisture Level on Installation Day Can Affect Longevity
The concrete pressed pilings depend on the weight of the home, combined with the moisture content of the soil on installation day, to continue working through time.
The moisture level of the soil at the time of installation impacts the effectiveness. It’s the moisture content of the soil pushing against the weight of the home that creates the needed spring-like tension. If the ground becomes dryer after installation, the tension weakens and the home will need to shift to maintain the pressure or fall out of a position of tension.
If the ground becomes wetter after installation, then tension increases and the piles may even push up, causing the home to raise higher at the support locations and come out of level.
The pressed pile pier repair job on the same home may go completely different and use a different number of cylinders pressed into each support location depending on the climate/moisture content of the soil at the time of installation.
For example, a lighter home built in the 1960s being repaired on a dry summer day will not press in the pile of cylinders very deep. But a new two-story stone house built in 2003 being repaired on a wet, winter day will find the pile of cylinders pressing more deeply into the ground and more cylinders being used.
Now imagine that the 1960’s home is being repaired on a wet, winter day and the stone home is being repaired in the middle of the summer. The tension created by the ground is different for each home and also depends on the time of year/climate conditions on install day.
No Assurance That the Piling Was Installed Vertical
Another *con* that can occur during installation: the pressing down of the cylinders can be knocked off course by a large rock, root, or tougher soil and veer from vertical.
There is no way for the installer to know if the piling is totally straight and aligned because they are pressing the pile into the ground through pressure. There is not a clear and continuous path, shaft, or hole already dug that the cylinders follow.
If the pile of cylinders is not vertical, and also not connected to one another, the stability and longevity of the repair can come into question. The pile also may not go deep enough to ensure long-term carrying capacity.
Live Load at Installation Time Can Be a (small) Factor
Another drawback, although minor, is that all the furniture and all your stuff inside the home, (also called the live load) at the time of installation can be a factor in how long this method lasts. If the weight changes by adding or taking away items from the home, the tension changes, and effectiveness can be compromised.
What Situations Or Homeowners Is The Pressed Pile Method Best Suited For?
As we mentioned earlier, the pressed pile system can be a better choice for certain types of situations and homeowners. Here is the “shortlist” of times when this method might work best for you.
- A homeowner that is selling soon and is not interested in longevity.
- An investor looking for a quick turnaround time.
- A homeowner with limited funds who wants the least cost to complete the repair.
- An investor who is trying to keep a remodel job under a certain budget.
- Anyone who doesn’t want the repair crew to be on site for a long time.
What Method Has More Longevity Than Pressed Piles?
So pressed piles are great for lower costs and quick installation, but not as great in the longevity department. When you are looking at spending a significant chunk of change on foundation repairs, you might want it to have longer-lasting results than pressed pilings can offer.
This is especially true for homeowners who are in their *forever home* and plan to stay for many years. You don’t want to go through the process and expense again anytime soon and you might be way more interested in a lifetime warranty and service agreement.
Anchor Foundation Repair only uses the drilled bell-bottom pier method of foundation repair. We find it is a great fit for homeowners who want to take the time to get the best foundation repair that your hard-earned dollars can buy.
We have done an article that presents the drilled pier method just as we have done with pressed piles. Check it out for comparison, “What Are the Pros and Cons of Drilled Pier Home Foundation Repair?”