Pier and Beam Foundation Leveling and Repair
If your foundation is leaning in a similar manner as the picture, then your pier and beam house needs foundation repair. Get a structural engineer to make you a pier and beam foundation repair plan so that all of the contractors can provide the same bid for the work. Without the engineers repair plan you are hoping that each contractor will put the right bid together.
We have seen some contractors lower their price to get the job which means they are also doing less and often times not enough to really fix it.
For Pier and Beam Foundations, standard practice is to replace the existing piers which have moved with piers that are more stable. There are different types of piers as well as different ways to build or install those piers. Some methods will significantly reduce the future potential movement for many years while other methods can only be seen as a temporary solution. Obviously, the more expensive the system used the better chances of a successful foundation leveling and stabilization.
The most common type of foundation leveling method in San Antonio and Austin for Pier and Beam Foundations consists in replacing the old piers (usually wood cedar posts) with new concrete piers. These concrete piers vary in diameter and are rested on top of square concrete footings which are a few feet below existing grade. The connection between the footing and the pier is through rebar. The size of the pier, footing, and rebar as well as the spacing and location is determined by a Structural Engineer.
In San Antonio and Austin, the previous described common method of leveling the pier and beam foundation is temporary because of the inherent nature of pier and beam foundation which will keep on moving due to the expansive clay soils. A better description of movement on pier and beam foundations is found in our Pier and Beam. Section.
The cost of the above mentioned method of foundation leveling is minimal in comparison with a more permanent solution and perhaps this is the reason almost everyone uses this type of system, which also explains why contractors who do offer a warranty offer it for only one year. Don’t blame the contractor or Structural Engineer if a house is not leveled again after a year or two, it’s just the nature of the beast. The Foundation will be better than before, but it will still move, unless you’re planning to spend substantially more for a better foundation leveling system. By the way, the building code doesn't allow the use of the traditional pier-and-beam foundation for new construction, unless it's an addition to an existing pier and beam foundation.
Slab on Grade Foundation Leveling and Repair
For slab on grade foundation types, by far the most common method of foundation leveling is the one that involves driving concrete cylinders into the ground until “refusal”, meaning, until the soil is so hard that the force of the jack is unable to push against the soil. There are some variations of this leveling method, but the main concept remains the same. These Piles are located below grade beams, and just like any other type of foundation repair, a Structural Engineer will assist in the design. This type of repair is called push piles or press piles.
Many are surprised to find out that this foundation leveling repair is many times temporary. One must remember that as long as bad soil is touching the foundation, there will always be movement of the foundation. A more in depth explanation of how foundations work is found in our Foundation Engineer Section.
In San Antonio and Austin, the main problem with the soil is that it shrinks when it is dry and it swells (expands) when it is wet. Therefore, the most common foundation leveling method discussed previously can only help when the soil shrinks (foundation settlement) if, and only if, it goes below the active region, but mostly not when it swells. But even for settlement cases, this type of repair is also temporary. There are many variations of this type of repair method, such as adding a cable through the sections of piles, but most of these methods still share a common flaw, and hence, they are for the most part temporary repairs.
There seems to be an illusion happening when several thousands of dollars are spent that give the impression that the foundation repair or foundation leveling is sound and will last forever. The cost of doing this kind of foundation work is considerably cheaper than a foundation stabilization method that would dramatically reduce the potential movement of the foundation.
Foundation leveling and repair for a structure very much depends on the level of expectation from the owner in combination with the available financial resources for the repair. The cost of a more permanent foundation fix is substantially (sometimes even 10 times) more expensive than the common methods used.
Essentially, a person who decides to buy a common foundation leveling and repair system is making a bet that they will not have to spend money on the foundation for another 'x' amount of years.
For a longer lasting, and many times even permanent foundation repair, there are two general methods regardless of the type of existing foundation in need of repair. One general method is to add drilled piers at a depth sufficient enough to avoid settling and heaving, but this also requires the entire structure (or most of it) to be completely off the ground (and different systems accomplish this in different ways, most commonly are the use of Helical Piers). The other general method requires changing the chemical composition of the soil supporting the structure (and there are several types of chemicals, environmentally safe).
Responsibility of the Structural Engineer
The structural engineer designs for public safety first and then to meet and find common grounds between the performance expectations and the financial commitment of the owner towards the foundation leveling. They also makes sure the foundation can safely support the loads without the building collapsing. Therefore, movement of the foundation is not a structural concern because it is agreed by the owner that the house will move, but not substantially as to cause collapse. If movement of the foundation is desired to be such that it will remain unnoticeable to the naked eye, then the structural engineer can design a more permanent foundation leveling system that will match the high cost of such a repair.
While many commercial structural engineers are aware of the pros and cons between the different foundation leveling and repair methodologies, most of the residential structural engineers are ignorant to the subject. When looking to hire a structural engineer, ask them to explain to you the different methods; if the answers are completely different than shown on this article and this website you can be suspect that engineer is not the most qualified to assist you with your foundation problems or even do inspections for foundation repair.
Elevations after Foundation Leveling and Repair
An additional service that a structural engineer can provide is doing a survey of the elevations of your structure after the foundation leveling and repair procedures have taken place so that there is a benchmark record of what was done and compare to future movements in the foundation.
This is not always done, but we recommend you always have the foundation elevations surveyed right after foundation leveling. You can have the structural engineer who helped you with the design or just hire another structural engineer. Not all structural engineers have elevation measurement equipment, A-1 Engineering is one of the few who does.And for more on where do you need a structural engineer in Austin, just click Structural Engineer Austin or structural engineer in San Antonio, just click Structural Engineer San Antonio.
We hope this article was very helpful to you, and if you have any more questions or need help on your next project in San Antonio or Austin or across Texas (including Boerne, San Marcos, New Braunfels, Poteet, etc,) please do not hesitate to contact us.