There are a variety of ways to underpin (i.e. lift up) a building that has settled and in this article we’re going to take a look at the difference between hydraulic piers and pressed concrete piers. We’re then going to explain why we recommend hydraulic piers for underpinning.
Structural damage is serious business. If you don’t take care of it right away – by hiring an experienced foundation professional – it will only get worse. What started out as a minor issue can turn into a big problem that will end up costing you even more money to fix.
What are hydraulic piers?
Hydraulic piers – made heavy duty steel – are installed under the foundation’s footing. (The footing is what spreads out a structure’s weight so the soil beneath it can handle the load.) A hydraulic ram is then used to drive the steel piers deep into the soil beneath the building until they reach the load-bearing strata. At that point, hydraulic jacks are placed on top of them, the structure is uniformly lifted back to its original position, and the jacks are removed. The piers remain permanently in place and the repair is invisible.
This short video shows how they work.
What are pressed concrete piers?
Pressed concrete piers are approximately 12 inches wide and 12-18 inches tall. They’re hydraulically pressed into the ground under your foundation until the building raises up to where it was before.
Why we recommend hydraulic piers
The difference between hydraulic piers and pressed concrete piers has to do with their ability to lift and stabilize a sunken foundation. Simply put, hydraulic piers are better than concrete piers for stabilizing a sunken foundation. Here’s why…
Because of friction, it’s impossible to drive a concrete pier all the way down to stable, load-bearing soil. They’ll go down maybe seven feet or so, but that’s it. If the load-bearing soil under your home is at eight feet, concrete piers aren’t going to fix the problem. All they’ll be doing is adding more concrete on top of soil that’s already having trouble holding up the building’s weight. In other words, concrete piers don’t solve the problem.
Also, you can never be sure how much weight an installed concrete pier will support. This is because the amount of pressure being used to drive the concrete pier into the soil isn’t monitored. Additionally, concrete piers that break during installation (yes, this does happen) can’t be removed or even repaired. Concrete piers have a high rate of failure.
Sure, in the short term, concrete piers are less expensive than hydraulic piers. However, you’ll pay more overall in the long term because you’ll probably end up installing hydraulic piers eventually to fix the problem once and for all.
In contrast with concrete piers, hydraulic piers easily go all the way down to load-bearing soil. They can lift any structure and are a permanent solution to foundation settlement. The installation is quick and there’s no need for heavy construction equipment.
To sum up…
Repairing foundations is not for amateurs. Only experienced professionals should undertake the task. Because a foundation repair can be costly, you want to make sure it’s done right, the first time. That’s why we recommend using hydraulic piers to lift and stabilize a structure. They go all the way down to load-bearing soil and they don’t fail. The fix is permanent and you never have to worry about it again.
Your best best is to catch foundation issues early, before they have a chance to develop into serious problems that require a repair, or worse, a foundation replacement.