Understanding all foundation repair or underpinning methods will help with your decision when deciding upon a foundation repair contractor. Some unscrupulous foundation repair contractors advertise that they can put in every type of piering system. Professional contractors concentrate on just one or two piering methods and master them. The contractors that claim to be a “jack of all trades” usually are the master of none. They generally take shortcuts and, due to that fact, they are not thoroughly trained in each specific method.
Professional foundation repair contractors that pick a system or two and stick with it generally can master the methods and provide a better quality job. They may not have the answer for every situation but they will generally provide better quality work on the jobs that they accept. They are also more likely to be recommended by professional engineers. If an engineer is putting his reputation on the line they generally will recommend professional underpinning contractors to perform the work they specify.
Knowing the positives and negatives of each foundation repair system is one more step in getting a job well done. All commonly accepted methods have their place or application where they shine. Some methods, like steel push piers and helical anchors, are more adaptable to unique situations, yet even they have their limitations. Using the correct method for your particular application is the difference between a job well done and a job that is less than satisfactory.
Steel push piers have an advantage over most systems in the fact that they are individually tested as they are installed. Professional underpinning contractors will monitor and record pressure readings and then compare them with structural weights to determine capacities. They will also use a manifold lifting system to perform any lifting required to make sure that the lift does not put any undue pressure on the structure. Professional engineers prefer manifold lifting systems especially high pressure (10,000psi) systems that can be controlled from a single place.
Helical pier systems are another very popular system recommended by many professional engineers. They are "screwed" in the soil using a helical gear motor or torque motor. Once again pressures and torque reading are monitored and recorded to establish capacities. Without carefully monitoring these reading a verifiable capacity cannot be assumed. Professional engineers generally want to review these readings to verify that the helical piers have reached soil layers that can support the structure. Manifold lifting systems are once again the preferred method of lifting.
Simply, homeowners need to ask questions of engineers and underpinning contractors before choosing a contractor. Stay away from the jack of all trades. Also be wary of the contractor who does not use a manifold lifting system. Many of these contractors use simple bottle jacks in their attempt to lift structures. These are all simple clues that you need to keep looking for a professional contractor. As always, hiring an independent professional engineer is the best course of action before any foundation repairs are started.