What is foundation repair?

The term “Foundation Repair” is misleading; the word “repair” typically denotes that something
is broken and needs fixing. Generally speaking, what takes place when a foundation has failed is
that it actually settles beyond an acceptable point, causing components of the superstructure to
become distressed or misaligned. This type of structural movement can and does lead to failures
of the superstructure components that can ultimately lead to total structure failure or collapse.
Now, total failure is a very extreme circumstance and is in no way common. More common
occurrences are damage to cosmetic veneers such as brick or stone, flooring such as ceramic
tiles, sheetrock, door frames and most commonly doors that do not fit in their frames and fail to
function properly.
The fix: Foundation Repair solutions can vary depending on the type of structure afflicted by
movement. For structures built on a concrete slab on grade the typical repair will consist of
some variation of piling, or pier for short. Once the needed pilings are installed the structure can
be vertically moved to appropriate surface levels as close to original elevation as possible.
Should the afflicted structure be of Pier & Beam or Block & Base construction (having a crawl
space under the house) the typical repair would consist of leveling the structure over the
existing block supports, with the addition or replacement of wooden components and or
concrete block materials.
Before we dive into how to fix the problems, let’s take a moment to look at the root cause of
foundation movement. Foundations typically do not fail due to age or poor construction, which
can be a source of deficiency but rarely is. Wood frame foundations such as pier & beam or
block & base substructures can fall into the above category because wood rots; the benefit to
this is that as long as the rot isn’t too significant, you can cut the rot out and replace the
necessary components. Concrete on the other hand does not rot the same way wood does, it
can and often does last for multiple lifetimes. Either type of foundation we mentioned above
will deflect or settle for one reason and one reason alone, dirt. These foundations, specifically
the ones built in the great state of Texas, are supported by the soil under the structure. When
the soil becomes displaced or moves due to expansion and contraction, the home built on top of
it will move accordingly. Soil will typically expand when it absorbs moisture and will contract
when it dries out, this increase and decrease in volume over time can and does lead to what we
know as settlement.
Several man-made factors absolutely induce movement. Poor drainage, plumbing leaks, poor
irrigation around the structure the lack of gutters, anything that can inconsistently increase
hydration in an isolated area certainly play a large part. Most foundation movement can be
attributed to severe inconsistencies in soil moisture content. Imagine walking through the yard
after a heavy rain and feeling the ground almost give below your feet. This is because the soil is
oversaturated and has experienced an altered density at the surface. Then imagine only weeks
after that a severe drought with extreme heat that rather quickly dry the soil. These extreme
variances in condition often cause rapid soil movement causing foundation movement.
Maintaining good lot hydration, function plumbing systems, gutters and proper drainage won’t

necessarily stop movement from taking place, but it can certainly slow it down or minimize the
damages to your home.
In short, the term “Foundation Repair” in most cases should be called foundation leveling via
underpinning. “Foundation Repair” is not quite as much of a mouthful and generally covers the
idea that something is wrong and needs attention; but the use of the term has created some
misconceptions within the world of homeownership and the industry.
Cracked slabs: Such a dramatically overused term used to oversimplify the issues and relay the
message that attention needs to be paid to the deficiency at hand. Check any engineering
manual written to cover concrete, every piece of concrete in the world has a crack of some form
or another in it; the Hoover Dam has cracks in it, yet it continues to this day to hold an
enormous amount of water that if released would cause catastrophe on an unimaginable scale.
Yes, your concrete slab home has cracks in the foundation; no, those cracks are in no way an
indication that the structure will collapse with you and your loved ones inside of it.
Corner cracks or spalling at the corners of the foundation. Obviously, it can be concerning when
a piece of a structural component cracks or falls off. Needless to say, someone will point out this
specific “deficiency” and claim that it is in need of structural repair. This can either be due to
general misinformation or can be used to incite fear in a homeowner and persuade them to
perform a job quicker than they may be ready to.
I could go on for days if not weeks about comical things I’ve heard homeowners tell me that
certain representatives in the industry have told them. I agree that every show needs a little
excitement, but when you are toying with one’s emotions in regards to what is probably their
biggest investment, honesty is the only policy. It seems to me that the vast majority of
misinformation within the industry has been regurgitated over and over in an effort to create
smoke without fire. If you, the reader, take only one piece of advice from this write up, take this;
vet your contractors, make sure they are qualified and do not hesitate to look into the
organization they represent. One day’s homework could save a lifetime of headaches.
Most concrete cracks in the drying stages and in order to begin to understand why we need to
get back to our high school science basics. The first question is: what happens when something
dries? Much like wet laundry, the drying of concrete is simply the evaporation of water. That
evaporation of water causes a chemical change in the cement that causes it to become very
dense and rigid, making it a suitable material to build structures on or out of. But what happens
to the volume of space occupied by the water that was once there? Much like a dish sponge
when left wet on the kitchen sink, the void doesn’t remain, rather the overall volume of the
piece of concrete is reduced by the volume of water removed in the drying process. Just like a
piece of cheesecake left out overnight, the shrinking of the concrete material results in small
fractures in the surface that may alarm someone none the wiser. These shrinkage cracks are not
in any way a structural deficiency and should cause zero worry, it’s all part of the process. For
further clarity, look up the definition of control joints in any construction dictionary.

Foundation repair relies on a couple of different factors, let’s discuss this regarding a concrete
slab on grade built to residential specifications. Factor number one is density, if the foundation
cannot withstand a compressive force sufficient to raise the structure, the repair will not
function. Second is stiffness or rigidity; if the concrete does not possess the proper stiffness it
may want to fold, for lack of better term, between the points of support. Support points can be
looked at as both the point where the foundation is supported by the pilings and the point
where the foundation is naturally resting on the soil. Most foundation repairs are partial
underpinnings where the entire slab is not afflicted by movement. A common example can be
that the right-hand side of the structure can have experienced settlement whereas the left-hand
side is as it was the day it was built. Most single-family residences are going to have a sufficient
foundation under the home and should withstand a repair job without much issue. Should the
foundation be too brittle or maybe too thin to provide the necessary stiffness, a proper solution
should be entertained from either your foundation repair contractor or an engineer.
Pressed Pilings: Here comes the biggest controversy in the industry. Do pressed pilings actually
work? The short answer is yes, they absolutely work; but not for the reasons you might think.
Let’s ask the question what tool is better, a hammer or a screwdriver? Both are used to secure
fasteners to wood, but neither one is better than the other; they simply perform different tasks
to ultimately perform the same end function of installing the fastener. The same argument can
be had for the variety of different piling methods. Pressed pilings only work when the
immediate load of the structure at the installation site of a particular piling is great enough to
overcome the resistance that the soil will apply to the piling segment as it is driven into the
earth. Fortunately for us, most single-family residences possess the proper immediate load and
stiffness to install the industry accepted segmented pressed pilings with boringly reliable results.
Understanding what we just discussed above regarding pressed pilings installed under a slab on
grade foundation we can move on to how a pressed piling works. Let’s talk table legs for a
moment, the way a table leg functions is that it transfers the load of that corner of the table to
the floor. The only way this load can be supported is if the load bearing substance (in this
example the floor) must withstand the increased pressures applied by the reduced surface area
of the table leg at its point of contact with the floor (if you have children the best example of
increased PSI is a barefoot step on a LEGO at 3am when you get up to turn off the lights
carelessly left on, the reduced surface area making contact with your bare foot makes the
encounter much more painful than a normal step on the floor). Fortunately, the floor in your
home is designed to withstand the weight of the entire superstructure and therefore will
indefinitely support your dining room table. This can also apply to pressed pilings but only in
very specific circumstances. Some type of load bearing strata needs to be available within the
depths your piling is capable of reaching which in speaking regarding sites located in Texas, can
be found where more accessible large deposits of limestone can serve as the kitchen floor as in
the above example.

More commonly, the pressed pilings act as a friction piling, where the resistance to support the
home comes from the applied friction of the soil being imposed to the entire surface area of the
pile shaft as it is driven into the earth, much like an oversized fence post. This friction applied to
the piling only increases as the pile is driven deeper into the ground, the two most common
factors that increase friction are the added density of the soil due to compaction and the
increase in applied surface area due to additional segments of the pile being installed. The more
surface area applied the better the frictional coefficient will be, therefore drag racing cars use
slick tires in leu of tires designed to perform in the rain; more contact area equals more traction.
Let’s explore an option, for example if the total dead load of the structure (weight as it normally
sits on the ground) is 100 tons or 200,000 pounds and we install 12 pressed pilings using 10 tons
of driving force due to that value being the immediate available load at the point of installation
we have a total resistive driving force of 120 tons or 240,000 pounds. Understanding that we
can only span our pilings a maximum of 8 linear feet on center in any direction before needing
another piling (on a single-story home) we can only cover a maximum of 96 linear feet not
counting odd install points such as corners, monolithic patios, fireplaces or wing walls. Your
typical single-story home that possesses a total of 100 tons should measure around 1,000
square feet. We can assume the example dimensions of a rectangular structure measuring 40
feet by 25 feet to equal our hypothetical 1,000 square feet. The perimeter will, in our example,
measure 130 linear feet leaving a minimum of 34 possible linear feet of the perimeter
untouched by our hypothetical foundation repair. Note that this does not include the interior of
the structure where piles can be installed if needed; we are discussing the installation of exterior
pilings only in this example. Returning to our values as stated above, our resistive force from our
pilings equaling 120 tons and our total structure load equaling 100 tons we have created 1.2
times the force needed to support the entire structure in order to solely support about ¾ of the
perimeter alone.
Now that the “nerd fest” is over and done with, all that information above is stated to say this:
Pressed pilings work on the total existing load of the structure in order to support individual
parts of the foundation. When used in conjunction with multiple pilings and installed correctly,
concrete segmented pressed pilings work wonders in permanently facilitating a foundation
repair or leveling job.
Let’s ask ourselves another question, when is it necessary to repair a foundation? Answering a
question with another question, when is it necessary to go see a doctor? The longer a problem
exists, the worse it usually gets, ignoring a pain in your leg could result in a blood clot reaching a
vital organ and causing severe complications potentially leading to your ultimate demise. A
festering foundation problem can lead to more extensive damages causing issues with a host of
other components such as plumbing, framing, roofing, safety and security concerns, the list goes
on. Next, we ask ourselves, when should a home undergo foundation repair? If I had a crystal
ball, I certainly wouldn’t waste that kind of power on predicting foundation movement; I’d be
sitting on a yacht floating blissfully in some unknown region of the Caribbean sipping a cool
drink and enjoying a nice cigar, thanks to my talents of predicting everything form lottery
numbers to the stock market. The unfortunate reality is that we cannot foresee when a

foundation will experience an issue, or even better yet whether that foundation will cease to
move in the future. The best advise that can be given in this regard is that movement in
foundations and their systems should be addressed as quickly as feasible, as to not only correct
the issues causing symptoms but to prevent other issues from arising. Remember this saying,
extensive equals expensive; fixing a problem today could result in thousands of dollars saved in
the future.
Overall, I think all above was stated to say this; be proactive, consult a professional, if you are
thoroughly confused call out an engineer to examine the issues at hand. Perform routine
maintenance to your home, have it inspected regularly, usually speaking it is your biggest
investment, and never turn a blind eye to those gut feelings when it comes to home repair.