Foundation Repairs
Selecting the Right Foundation Repair
There are many ways to lift a foundation. The key is knowing which technique to use in each situation. Deciding which approach is right for you means we look at the house, at the soils, and the home support.
The most important factors to consider when looking at a house are:
- The depth of the foundation
- The type of reinforcing in the foundation
- The size of the foundation (length and width)
- The condition of both the foundation and the house.
Advanced Foundation Repair’s technicians help you determine the best supports for your home.
Select your option!
CONCRETE PRESSED PILINGS
Ideal usage: For homes that are built on plastic clay soils. This type of soil is very pliable and is highly affected by water, or the lack of water.
Description: Concrete Pressed pilings are 6 inches in diameter. They must be forced down into the ground with pressure. This means that soils must be able to flow out of the path of a piling at its tip. Concrete pilings are made of sections that are stacked on top of each other, so they must be reinforced with rigid steel bars. These steel bars keep the pilings straight during installation and strengthen the concrete. Because the materials costs for concrete pilings are lower than the materials costs for steel pilings, it makes sense to use concrete pilings if the soils are suitable.
STEEL PRESSED PILINGS
Ideal usage:
• When less movement of the home’s foundation is preferred
• When deeper pilings are needed
Description:
Like concrete pilings, steel pilings are pushed into the ground. Steel pilings are usually only 3 inches in diameter, versus 6 inches for concrete pilings. In contrast to concrete pilings, which have a rough surface, steel pilings have a smooth surface. Because of the differences in diameter and surface texture, driving a steel piling into the ground takes less than 1/5th as much pressure as driving a concrete piling. As a result, the installation process for steel pilings often (but not always) results in much less movement during the installation process than the movement that occurs with concrete pilings. Unless a piling hits rock, a steel piling will always go deeper than a concrete piling, for a given amount of pressure.
Steel pilings cause less movement during installation than concrete pilings and typically go deeper than concrete pilings, so why not always use steel pilings?
· The first reason is cost. Steel pilings can cost twice as much as concrete pilings. If soils are suitable for concrete pilings, why spend the extra money on steel?
· The second reason has to do with corrosion. Some soils will eat up steel over time. For example, nobody would suggest using steel pilings in Galveston, where the ground water is salty.
DRILLED PIERS
Ideal usage:
• When it is important to minimize movement of the
foundation before lifting.
• When the soils are too hard to drive steel or concrete
pilings through
Description:
For some structures, it is not possible to generate enough pressure to drive a steel or concrete piling. This is particularly true for small structures. In such cases, the process of driving a piling can literally lift the majority of a small structure off of the ground without generating enough pressure to drive a piling. At other times, a home may have loose and unstable brick veneer, or other problems that make minimizing pre-lift movement important.
When drilled piers are installed, it is necessary to drill a shaft deep into the ground. All of the dirt that is drilled out of the ground must be hauled off. After the shafts are drilled, steel reinforcing must be lowered into the shafts. Next concrete must be carried in and poured into the shafts. Finally, the concrete must cure for a week before it can be used to lift a foundation. What all this means is that drilled shafts are much messier and much slower to install than pilings. As a result, drilled piers are generally only used when there is a specific need.
SPECIALTY APPLICATIONS
Advanced Foundation Repair can engineer solutions for difficult problems and unusual situations. For Example:
• Lightly reinforced slabs. In some instances, the best approach is to lift the perimeter with pilings and to lift the interior with polyurethane injection. Polyurethane injection can be used to lift very light structures without tunneling underneath or cutting holes in floors. Our companies have used this approach frequently in Amarillo.
• Severed reinforcing cables: In one instance, all but one of the reinforcing cables in a foundation had been severed. Before lifting the building, it was necessary to bolt an external steel reinforcing system to the foundation.