What are Push Piers?
If you start to notice that your foundation is sinking, it can be a daunting prospect. The idea that your house is sinking, that the walls are cracking, and the doors and windows are no longer opening smoothly may seem catastrophic. However, push piers may be the solution you, your home, and your foundation need.
This guide will discuss all of the key aspects of push piers, from what they are, how they are installed, and when they’re best suited to fixing your home’s problems. So don’t panic. Read on, and you’ll have the information you need to get to work fixing your sinking foundation.
What are the Components of a Push pier?
Push piers are relatively simple pieces of equipment and, therefore, are made up of only three components.
Remedial Bracket
The remedial bracket is what connects the steel pipes to the footing of the structure. These are vital in ensuring that the weight of the structure is held tight against the push pier. The brackets are designed as an L-shape, with a 90-degree bend. This helps them to fit flush against the footing of the building. The brackets vary in terms of material and size, although they are generally sturdy and weigh, on average, around 70 lbs.
Starter
The starter is the first piece of metal tubing; it can be either cylindrical or cuboid. It is what helps the push pier to enter into the ground. These are the bottom level of the push pier onto which the extensions are added. They usually come complete with a skin friction collar, which makes it easier for the tube to pass through the earth as it is shunted down.
Extensions
The extensions are further pieces of steel piping (they can be cylindrical or cuboid but generally take the same shape as the starter piece). They are attached to the starter piece in as many sections as needed in order to achieve the desired length. Once the starter piece has reached the desired depth and the load-bearing stratum has been reached, the final extension will connect with the remedial bracket, which will then take the load of the building onto the piers.
How are Push Piers Installed?
If you need to install push piers, then there is some preparation work that will need to go into the process. The entire project is a multi-step affair. Although the exact specifics will vary depending on your circumstances, you can usually expect the following:
- Inspection. The first step is the inspection stage. The contractor will conduct a tour of your property to check whether utilities such as water, gas, electricity will be affected. The contractor will also usually place tape to mark out where the push piers will be placed.
- Excavation. The contractor will dig out 3 x 3-foot excavations where each push pier will go. This will allow the brackets to attach to the footing.
- Bracketing. The footing is chipped with a jackhammer to allow the bracket to fit flush against it. The bracket will then be mounted securely against the footing.
- Driving. Using a hydraulic ram, the piers are pushed into the ground. The starter piece is sent in first, followed by the extension pieces. The actual depth of the piers varies depending on the soil and the weight of the building. On average, the piers are driven to a depth of 25 feet.
- Foaming. This process creates a void underneath the home. Polyurethane foam will be injected into the void. This helps to provide support for the building, as well as prevent vermin from being able to make nests in the space.
- Backfilling. Once the lift is complete and the piers are connected to the bracket, the area can be backfilled, and any shrubbery or turf can be replaced. The work is now complete.
Push Piers Versus Helical Piers
Something you’ll need to consider if you do need to raise your concrete foundation slab is what type of piers you’ll need to use. There are two main types commonly used – push piers and helical piers. Push piers are the most commonly used, but helical piers are more suited to certain types of situations.
The key difference between the two is that push piers are literally ‘pushed’ into the ground using a hydraulic ram. You can think of them as giant nails being hammered into the ground. By contrast, helical piers are giant screws. They have helical plates arranged around a central cylinder. They are then turned into the ground, which causes them to be drilled ever deeper into the ground.
Which one is right for you is dependent on the specific issue affecting your foundation as well as the size of your home (or other building in question). Push piers tend to be better suited to large buildings or buildings that utilize a lot of concrete – this causes them to be heavier. Push piers rely on the weight of the building to achieve the requisite depth.
By contrast, helical piers are better suited to structures that aren’t as heavy. This often means buildings that are less than two stories and homes that aren’t built with a lot of concrete. Helical piers are anchored in the ground due to the torque of the soil, so they don’t need the building as leverage.
What are the Strengths of Push Piers?
Even though helical piers are better in some situations than push piers, there is a reason why the majority of projects use a piering system. Push piers have plenty of strengths, particularly compared with other means of lifting a concrete slab. Some of these advantages include the following:
- Strength. Despite push piers being hollow cylinders (and therefore relatively lightweight), they are extremely strong. Their compressive strength can easily hold up the weight of a foundation slab. In addition, because the pipes are hollow, it’s relatively easy to further strengthen them by adding grout or even rebar to increase lateral stability.
- Space. Push piers are easy to install in limited spaces because they are effectively a modular construction. You only need to feed in three-foot extension pipes at a time, meaning that the whole process doesn’t require a great deal of room in which to operate. In fact, the entire project can take place in a space three feet by three feet, with an overhead clearance of six feet.
- Heavy building repair. As mentioned above, push piers tend to work best with heavy buildings since their function is an equal and opposite force to the ground underneath. The heavier the building, the stronger the push pier and the better the overall connection.
- Endurance. Push piers can last for a long time before they need repairing or replacing. Unless there is a great deal of lateral movement (such as with a seismic event), it’s unlikely you’ll need to do anything with your push piers for at least thirty years.
What are the Limitations of Push Piers?
Despite the clear and obvious advantages of push piers, they are far from perfect. In some situations, other types of foundation lifting may be better suited. This is why it’s important to speak to a professional in advance of any work starting. Some limitations include the following:
- Light loads. If you have a foundation slab sinking in a garage or a shed, push piers are unlikely to be effective. These structures simply don’t have the force required to work well with push piers.
- Flexibility. Once you have the push piers in place, you can’t remove or relocate them. This could cause problems if you were to add an addition to your home. The extra weight would change the nature of the forces involved, but the existing push piers would not be able to respond, nor is it possible to move them to the correct location.
- Broken footings. If your footing is broken, then push piers won't work. Any major damage to your foundation slab and a push pier system is likely to exacerbate, not fix. If you find any cracking or breaking in your foundation, you’ll need to look for another system.
- Vertical-only. Because of the way that piers are installed, they are not suitable for anything that requires a different angle. For example, if your walls are bowing, you’ll likely need bracing at an angle away from the vertical. Push piers don’t work in this situation. Push piers only work with the direct up and down movement of gravity.
For all their simplicity, push piers can greatly benefit your home or other building. If your foundation is sinking due to shifting or eroding soil, it can seem like your home is built on sand. However, push piers are able to provide the support your building needs, allowing you the peace of mind to continue living in your home. Most importantly, it means your home will retain its structure, its strength, and its value, and all of this at very little financial expense. Push piers will not only solve your problems but will do so for the long term.