This page is provided as a basic informative summary of availabe foundation repair techniques.
Please be aware that some of the processes used by companies claiming to have the best systems, are simply
temporary solutions to a permanent problem. Mother nature can be un-kind in particular regions where flood, or drought issues
amplify problems with earth hold integrity (foundation support).
This list of processes is provided to you, as a helpful tool that may give you the answers to many important
questions about building foundation problems. The majority of foundation failures can be attributed to soil conditions, however,
the questions: Why here?, Why now?,, especially when the structure has been fine for many years, and then suddenly there appears
to be sinking and twisting of the foundation.
Please examine the list of repair processes below, and consult with a structural engineer about your particular
problem. Your choice of repair technique can be critical in the determination of how permanent the repairs will be.
1. Adding a larger footing or pilon blocks
This process is still used by many contractors as a quick-fix, and can be effective
in lighter structures such as patio enclosures, sun rooms, green houses, sheds and outbuildings, etc. The thing to keep in
mind about this type of repair is this: Should the soil around the structure be un-stabil, then the addition of concrete may
temporarily provide a slightly better displacement of load carrying capability, but in the years to come, it could in fact
amplify the initial problem. EXAMPLE: If someone was standing in quick-sand crying for help, would you place concrete blocks
around them?
2. Mudjacking
This is a very effective way of restoring the elevation of sunken pads and wide surfaced
concrete areas that can be floated back upward to near perfect position. The repair can often times be considered permanent,
however, this process addresses the immediate problem, and cannot solve deep soil problems such as: saturation from negative
grade, plate settling, cavitation of lower regions, clay soil contraction from drought, etc.
The mudjacking process is a technique that involves drilling holes through the pad
and attaching a pressure hose that is supplied with pumped sand slurry that spreads beneath the concrete with a hydraulic
action that floats the concrete upward to a desired elevation. It is an excellent alternative to removing and replacing the
concrete. The cost for this process is much less than replacing the concrete, and usually restores the elevation of the pad
to a satifactory appearance. This process is often times used for: Driveways, Basement floors, Pad porches, Sidewalks, Monolithic
supported structures, Wide based concrete pads of all types..
3. Helical Piers
This is a very effective way to support and stabilize, and even lift, concrete foundations
of all types. This process has come about during the last 15 years or so, and is being represented as the very best way to
solve foundation stabilizing problems. The process is quite interesting in it's approach to holding structures, it is theoretically
correct, and makes logical sense,, but,, it creates certain questions: Just how deep can these piers be twisted into the ground
before refusal?,, Have they ever been sheared at particular depths where heavy gravels, or shale were present?,, What happens
when the spiraling flights come into contact with crevace conditions or fault lines?.. Sinse the system relies entirely upon
resistance, It may be somewhat experimental in some regions where underlying conditions may be unknown.
The helical piering system is installed by similar brackets that compression piers
have always used, but the pier installation is very different. The piers are twisted into the earth by hydraulic drive motors,
(much like a post-hole auger bit), The surrounding auger blades on the piers are called flights. I find that to be a very
interesting name. The process is: Drilling & Twisting into the earth, and has very little to do with aerodynamics (un-like
an airplane prop)..
The thing to keep in mind about this process is the newness of this technology, and
the overall success rates are very impressive, but what about the duration of the hold? Example: some regions of the country
have sliding plates, and deep cavitation. Would a system that rarely reaches bedrock, be considered a lifetime hold?
4. Compression Piers To Bedrock
This process has been the choice of more structural
engineers throughout the years than any other proven method known to man. It is effective 94% of the time on all heavy structures.
Residential and commercial buildings that are quite heavy and sinking for whatever reason. Soil conditions usually do not
affect the foundation, once this system is installed, because the overall hold of the structure is upon solid bedrock. The
steel piers (columns) are pressed hydraulically downward to bedrock, and then the structure is lifted to desired elevation
and pinned into position permanently. This can usually be lifetime guaranteed.
The only limitations of this type system are as follows: The structure must be heavy
enough to provide the needed resistance to press the individual piers to bedrock depths, otherwise the structure may in fact
begin lifting before the desired depths are obtained, However, if this happens, there is usually adequate holding power to
provide for a much greater support than the failing foundation itself.
We believe the compression piering method to be the best overall choice for
a number of reasons: Cost of repairs are usually reasonable, Overall results are usually excellent, The intrusion around the
structure is minimal, The speed of the process is absolutely amazing, (Most repairs in 1 week or less).
This article is being written with the hopes than a better understanding of foundation
repairs, might be presented to contractors, and homeowners alike. We also strongly suggest that structural engineers be contacted
when making decisions about serious foundation problems. We welcome questions and will be happy to provide contacts with Soil
experts, and the very best Structural Engineers.
Written By: Ed Eckley 1-15-06
