FOUNDATION REPAIR WARRANTY LOOPHOLES
For starters, foundation repair companies have sent us tons of hate mail and comments for this next discussion. Most foundation repair warranties contain extensive language that gets them out of the warranty for servicing the piers they install.
The stated exclusion conditions on the warranty typically already exist before and well after the foundation repair company installs the foundation repair piers. So... if a foundation repair company installs their foundation repair piers in conditions that already caused foundation problems, they will SCAM you out of warranty work by claiming that the bad conditions exist, as noted on their warranty declaration. Thousands of our clients who have been caught up in this have all echoed the same response.........."why didn't the foundation repair company tell me I had bad conditions and that their piers don't work under those bad conditions. Now they want me to do more 'foundation repair' to fix the problem".
The first issue is that foundation repair is being seen as the solution. This is where a structural engineer's evaluation comes in. A-1 Engineering is an expert at assessing buildings to provide you with our non-biased and objective opinion on whether your building will benefit from foundation repair.
"FOUNDATION REPAIR TO STABILIZE MY FOUNDATION"?
At times, foundation repair is sold to owners with the promise of providing a "preventative measure" or a method of "stabilization" before a foundation problem occurs. What healthy person gets a hip replacement or a kidney transplant as a preventative measure to stay healthy? Most would agree that to stay healthy, you should create better conditions for your body. That is the same for a foundation and a building. Getting an evaluation from a structural engineer will help you better understand when conditions warrant foundation repair and the associated risks.
In our experience, foundations go bad (i.e., need re-leveling) as soon as 6 months after the repair and as late as 10 years - the reason being that foundation repair companies don't understand how foundations are designed and expected to perform. Foundation repair companies will tell you that foundation movement is "foundation failure". A structural engineer who is familiar with the impacts of foundation repair will educate you on how foundations are designed, expected to perform, and discuss conditions to improve the performance of the foundation.
Don't let foundation repair companies scare you or confuse you into lifting a building without a clear objective. The following article is meant to educate the general public and assist in making better choices. Foundation repair is a very expensive major surgery to a house, so it would be in your best interest to get a second opinion.
Here are some great questions to ask the foundation repair companies:
1) How many projects did you honor a warranty on this past summer?
2) Can you provide a reference for one of the clients that you honored the warranty work on?
3) Can you revise your warranty agreement to cover the piles or piers in case of swelling or heaving soils?
4) Explain how your pile or pier is expected to perform when soils heave or swell? Will your pile fail, and is that covered in your warranty?
5) It's not a bad idea to tie payment for the work with proof that permits have been obtained for the work. The first payment can be tied with proof that the permit has been obtained, and the final payment should be tied with proof that the permit has been closed. Red flags should go up if a contractor cannot obtain a permit OR if they say the homeowner is required to obtain the permit. The person who gets the permit is responsible for managing it.
6) If you get convinced to get the work done, be sure to get a copy of the elevation readings before and after the work is done. It's a great idea to retain the final payment until both documents are provided. Also, be sure that you can read the numbers. Getting a paper with numbers that are hard to read does you no good in case you want to get the numbers checked.
USELESS FOUNDATION REPAIR
By far, the most common type of foundation repair used in San Antonio and Austin is the concrete press pile, also known as a push or forced pile. Unfortunately, this is, for the most part, also one of the most useless and ineffective types of foundation repairs or foundation stabilization that you can get. This is not just our opinion, but also the opinion of many, if not the vast majority, of independent engineers (structural and geotechnical engineers).
A concrete pressed pile or push pile foundation repair consists of cylindrical concrete pieces, usually 6" in diameter x 12" in length, which are pushed or pressed into the soil and below the existing foundation beams with the weight of the house. Sometimes these piles might be called piers, but strictly speaking that's not the correct terminology. These cylinders are considered precast concrete driven piles, which the building code says would need to be at least 8 in diameter in order to meet code (yes, without even going into calculations and formulas and complicated Engineering stuff, this system is code non-compliant already).
The intended purpose of this repair system is that, as you push down these round concrete sections, you will eventually reach soil that is very hard or stiff, not necessarily rock (actually, most of the time it is not rock, especially in San Antonio). Usually this is known as driving until refusal. Once you have reached this very stiff stratum of soil (supposedly), the hydraulic jack won't be able to keep on pushing the sections of concrete down because the force required to push the piles down is more than the proportional weight of the house; at this point, the hydraulic jack will start lifting (leveling) the existing foundation of the house. We ought to say that even this very stiff stratum of soil may in fact not be a very stiff stratum of soil but instead the very same bad soil; it may just be that the friction of the soil, or the accidental tilting of the section, creates a bigger bearing area, or whatever other reason, is preventing the concrete sections from being pushed any further.
DIFFERENT CONCRETE PRESSED PILES = SAME COMMON FLAW
There are different types of systems, but all they are is mainly a slight variation of the same push pile or press pile foundation leveling repair system. Some companies run a cable through the different cylindrical sections; others place a steel pipe at the bottom and then install the typical push piles on top. Another system uses a combination of steel pipes and concrete push piles, while others use 100% concrete sections and inject water or a chemical by hand into the soil surface.
The reason there are different systems that are basically slight variations of the original system is mainly due to competition. Foundation repair companies need to differentiate themselves from each other because, after all, there are literally dozens and dozens of foundation repair companies in Austin and San Antonio, so they need to claim their system is better than their competitors. But foundation repair companies are also interested in obtaining patents for each system they develop, presumably giving them the upper hand over their competitors.
Almost all of these systems do not effectively repair or level a foundation because they mainly share the same flaw. This flaw is that the piles themselves are not deep enough and do not act monolithically (i.e., do not act as one piece), and because they are surrounded by bad soil, the piles will be subjected to the same heaving and settlement that the original slab is subjected to.
As long as concrete push piles (in sections) are used, the foundation repair system will almost always be temporary.
WHY LEVELING A HOME WITH CONCRETE PRESSED PILES DOES NOT WORK
There is a zone in the soil known by geotechnical and Structural Engineers as the active zone. This zone is a specific depth of soil in which moisture content (i.e., water) varies as environmental conditions change (e.g., temperature, rainfall, sun exposure). As long as a foundation is bearing within this zone, it will move with changes in soil moisture content. If the soil is dry, then the soil (clay) will shrink, and the foundation will settle; if the soil is wet, the soil (clay) will expand, and the foundation will heave.
But poor soil in the active region also affects piers and pile foundations, regardless of whether they bear below the active soil. The reason is that changes in soil water content create suction on the surface of the pile or pier (i.e., swelling of the soil pushes on the pile through skin friction), thus causing the pile or pier to heave. Yes, you read right, the pile or pier will move up! The problem with press piles is that, although the piles are pushed into much harder soil (or so they claim), this soil is still poor within the active zone and will therefore move up or down as soil moisture changes.
A way to prevent heaving or settling of a press pile foundation repair system is to ensure that the entire pile works as one unit, monolithically, and extends to a sufficient depth so that it stays away from the soil active zone and prevents uplift of the pile. This is almost impossible for a press pile, even for those foundation systems where the post-tensioned cables run through the middle of the pile! This is because the cable goes through what is called relaxation, and the force on the cable might be too small (sometimes too large, and it breaks the cylinders embedded into the ground without the installer knowing it) or not effective since the pile is usually not straight when it is pushed into the ground. The cable is also not protected from rusting. Eventually, clay soil will get in between the sections and keep on pulling the pile apart (again, most of the time the piles will not reach below the active region anyway, so it does not matter even if you are able to install a full monolithic section; the pile will still eventually move). Don't be misled by companies who claim they have been around for 20, 30, or even 50 years. If you have been painting for 50 years, it does not make you Picasso; nor does having 50 years of experience doing a repair, mostly the wrong way, make the foundation repair any better. Coincidentally, we learned recently (2011) that one of the biggest and most famous major foundation repair companies that provides a similar system had to file for bankruptcy protection after many homeowners banded together and brought in a lawyer.
Interestingly enough, many foundation repair companies will tell you that they pushed the concrete press piles down to 10ft or 12ft in San Antonio, for example. They are in fact telling you that, if the piles were pushed exactly straight (highly unlikely), they have not gone well past the generally accepted depth of the active zone, which by definition means that the piles will eventually move even for those systems that claim to positively connect the cylindrical pieces to each other. In other words, many foundation repair companies are telling you and admitting from the beginning (without them knowing) that what they are installing will likely make your foundation move again.
NEGATIVE SIDE EFFECTS FROM BAD FOUNDATION REPAIR
There are many negative side effects to foundation leveling repair through concrete press piles. The first negative side effect is that you will likely develop more cracks in the walls and slab than you did before any foundation repair. Ideally, when you push up on the foundation, the cracks should close, but in practice, the way the lifting operations are carried out will create additional cracks. Be prepared to add the cost of more repairs to project costs.
Another negative side effect of leveling the foundation with press piles is that you may damage plumbing beneath the slab, creating an even bigger problem than you had before the foundation repair.
You may also distort the roof and therefore create leaks that you may not have had before. Do you have floor tiles? They will likely crack too.
Eventually, many of these piles will move and re-create the damage you had before.