All parties to vibration damage occurrences agree that damage is not a desirable outcome of construction work. Most damage is relatively easily avoidable
at virtually no additional cost. So, why does construction damage
occur repeatedly worldwide, what does it mean for those affected, and what can be done to prevent it or resolve it fairly and at minimum cost when it does happen?
The Responsible, the Irresponsible and the Indifferent
or other structures are particularly close to construction activities
(e.g. within 25 ft. or so), it's not unheard of
for even careful, responsible, well-meaning contractors to cause relatively minor damage to nearby structures. Such responsible contractors will usually be reasonable about resolving any damage claims. It's just good business for them to
realize that they will spend more time, money, goodwill and future credibility fighting a legitimate damage claim than they will in just paying the claim (or having their insurer pay it), with apologies.
More serious construction vibration damage
(e.g. wall penetration cracking at right) can happen when construction companies put profit over safety, don't care enough to show
due prudence, don't understand the risks, perform operations on site in manners which violate company rules and/or operator's manuals for the involved equipment, fail to use free, well-known and published vibration mitigation
procedures, are given poor information and advice about vibration effects by their paid "consultants" or some combination thereof. When damage is reported in connection with their work,
such contractors, project sponsors and their employees all too often rationalize the damage away. They tell themselves (and just about everybody else) that "construction
can't cause damage", as well as operating under and putting forth other misconceptions. They are probably completely unaware of both the lack of any supporting evidence for their assertions and the massive evidence to the contrary in the scientific literature of vibration damage. Such a biased and scientifically unjustified attitude means that the contractor's employees likely will do more damage
in future projects.
There are some contractors who
regularly employ equipment with well-known risks too close to homes and buildings, make questionable choices among those types of equipment available (e.g. choosing compactors with nominal vibration frequencies below 40 Hz), then compound the errors by making highly doubtful and unnecessary decisions about the way they carry out operations (e.g. repeated vibratory compaction of pavement
butt joints perpendicular to the street direction, as shown in the photo, directly in front of homes known to the contractor to have been damaged by its previous work). These companies seem to generate damage complaints, and even litigation, in job
after job. Searching the
web during the process of researching a claim (see Researching A Claim in the CVDG Pro for more) will usually uncover multiple examples of lawsuits filed against such contractors. Some of the claims may involve damage claims, while
others may allege shoddy work or contract non-performance.
Sometimes, You Get What You Pay For
One might think that, after a while, these uncaring and/or dishonest contractors' reputations would catch up with them. However, that isn't necessarily the case. It may not matter in the slightest, if the bad reputation is known to the project
sponsor and others connected with proposed project.
Those who believe a project sponsor will take due care in contracting for and assuring proper and responsible performance of a construction job using heavy equipment may be badly
There may be some good reasons
(and some very bad ones) why project sponsors, particularly public entities, may continue to award contracts to contractors with poor
records. Perhaps the most important of these is a low-bid requirement. Ordinances or state laws may virtually require a public sponsor to accept the low bid, even from a contractor with a long record of damaging the property
of others. Private project owners also may feel strong pressure to accept low bids.
If you have construction using heavy equipment ongoing or
about to occur in your area (within a city block, roughly2), you would be well-advised to check up on the contractor by searching the web for other litigation and complaints. You may not be able to stop the use of that contractor.
But you can, at least, prepare yourself to deal with damage if it occurs, by finding out what kinds of complaints there have been in the past. You can find much more on how to do this in the CVDG Pro's Researching A Claim chapter and in the CVDG's
Consequences of Vibration Damage
Based on information gleaned from visitors worldwide to Vibrationdamage.com, it appears to be extremely rare for construction firms and project sponsors to accept willingly any part of the
responsibility for damage, no matter what their contractual responsibilities might be for making right the damage they bring about or how overwhelming the evidence supporting construction causation.7 In most cases, the result of vibration damage is either that the injured party ends up paying for the irresponsibility of the contractor and sponsor out of his own pocket or
that all the parties together must spend far more in litigation-related
costs than would typically be required to fix completely all the damage.
Ultimately, that low state of affairs places most of the financial, and nuisance, burden on the homeowner, even though he has no control over the construction,
into the construction contract and no share of the construction profits. Under the current system of funding projects and rewarding on-time completion, the contractor gets paid his contract fee and completion bonuses whether or not he damages surrounding homes and no matter how many he damages.
Such policies are easy to justify when you start from the unquestionably false premise that "construction can't cause damage". There are few, if any, real checks and balances to limit damage, even though construction contracts usually include standard provisions which, in theory, make the contractor "responsible" for damage. The aggrieved homeowner
likely will get
little satisfaction from such contract provisions.
However, even the
contractor will pay a price for causing damage in increased insurance costs, making its proposals less competitive and less profitable. These effects could lead fewer awards of contracts. In addition to litigation costs, the sponsor will pay in higher project and insurance costs, as well as increased resistance from homeowners to future projects.
That resistance means projects will be slowed or stopped entirely, costing the sponsor extra money.4 Taxpayers will pay in settlement and litigation costs for public projects. Public entities will pay due to decreased property
values, which lower the tax base. To paraphrase
the English poet John Donne,5 ask not who pays for construction vibration damage. In the end, we all will, even if the burden falls disproportionately and unfairly on those whose homes are unnecessarily damaged by
construction with heavy equipment.
Avoiding Damage Proactively
Construction vibration can be mitigated to safer levels by well-known and publicly available procedures, which are discussed in brief in the CVDG's
Vibration 101 chapter and, in much more detail, in the CVDG Pro's Vibration Mitigation chapter. Some attention to what equipment is used and how is often all
that is needed to avert damage.3 Biased and self-serving attitudes to the effect that "construction can't cause damage" often contribute to repeated damage, but
are directly and strongly contradicted by the scientific literature of vibration effects.
Project sponsors can sometimes bear as much moral (and legal) responsibility for damage as the contractor, if they haven't made even the most
basic effort to prevent or minimize damage. Yet, some simple steps can help
fulfill this responsibility:
- Exercise due diligence over the job - If the sponsor doesn't monitor the
construction, regularly and at random times, for proper use of equipment, doesn't have in place basic regulations regarding the use of heavy equipment in construction, doesn't demand vibration monitoring for
at least the riskiest operations, like pile driving and compaction, doesn't respond in good faith to complaints of damage, or
simply doesn't care once the project is started, damage potential is greatly increased by these failures to perform the most basic of due diligence. Construction work can't be meaningfully monitored by phone from a desk miles from the construction site
or by driving through the construction zone at the speed limit. See For Project Sponsors and Using a Vibration Monitor Firm in the CVDG Pro for more information on how to monitor a job to forestall damage.
- Contract to reduce damage - Project sponsors must include and enforce provisions in contracts for
handling vibration damage claims. They should withhold early completion and on-time completion bonuses until
any legitimate vibration damage claims are resolved. Paying a contractor a bonus for a project in which it is known that multiple homes have been damaged is to assure that the sponsor will find itself in the same situation again.
- Enforce the contract provisions - It does absolutely no good to write provisions for pre-construction surveys, job vibration monitoring, and vibration mitigation into the contract, if the contractor simply ignores
them, as is often the case. Demand to see the results of these requirements in a timely fashion. Suspend work and/or end the contract for non-performance if they are not carried out and or the results not provided for
- Require vibration monitoring - Any project in which either vibratory compactors or pile drivers are used within 50 feet of homes or other structures should be required to have a scientifically meaningful and defensible vibration monitoring program.
Such monitoring is already a standard part of many construction contracts in the public sector, although at least some contractors routinely circumvent that requirement. The monitoring
industry-accepted procedures for measuring the vibration velocities and provide real-time feedback to construction workers. For any public-funded project, the raw data from this monitoring should be a specified deliverable.
Then, it should be made available in toto online to anyone who wants it as soon after the data are recorded as
possible, along with links to free software which can be used to analyze it. Any gaps in information (e.g. partial or full work days missing data) must be identified and resolved quickly, as well as explained online.
- Use appropriate vibration standards - Many U.S. states and most municipalities worldwide have in place few, if any, appropriate vibration standards for construction. Having such
standards is critical in allowing vibration monitoring results to be used to direct construction toward less damaging methods. Since blasting standards are clearly and indisputably inappropriate for construction vibration,4 use of
them is both immediately challengeable and likely to lead to damage. Instituting construction vibration standards and providing guidance for implementing them is perhaps the
most important thing regulatory entities can do to stop unnecessary
damage, prevent expensive litigation and regain confidence of those who live near construction sites where heavy equipment is used. Currently, damage is so frequent and widespread all over the world6 that the opportunities for
improvement are almost unlimited. For more on developing a program for construction vibration monitoring, see the CVDG Pro's Using a Vibration Monitor Firm.
- Treat homeowners with basic respect - Sweeping vibration damage "under the rug" or trying to intimidate the innocent victims
will sometimes have expensive and, often, unforeseen consequences. Since government project sponsors often argue that "construction can't cause damage", they should back their (unsupported) beliefs with insurance policies that will pay legitimate vibration damage
claims, without forcing the homeowner to fight it out in the courts. Doing so will save everyone money and avoid alienating taxpayers and reducing the tax base.
Construction vibration damage is mostly, if not entirely, preventable. It occurs far too often because it is poorly understood by those financing and performing the work and largely exempted from both unbiased examination and responsibility. Clearly, it
is better to exercise basic prevention steps of little or no cost impact on the project than to fix the likely expensive damage after the fact - or, worse yet, to try to "solve" the problem in the courts. A legal approach is both far more expensive (usually even than the cost of
complete repair) and less likely to yield a fair resolution. Even a win in court for the sponsor or contractor will likely have negative repercussions that can last for years. Yet, those contractors and project sponsors who try to
evade responsibility for extensive, widespread and well-documented damage are almost certainly forcing the homeowner(s) to file suit.
In the end, handling and preventing vibration damage is about respecting the rights and property of innocent home
and building owners just as much as those who own or run construction projects expect cooperation from them.
As the public becomes more and more knowledgeable about the real risks of construction vibration damage, construction projects will become more contentious and expensive, unless those who fund and perform them face the reality
of vibration damage. They can then take serious, but mostly relatively cheap and easy, steps to prevent it. A contractor or sponsor who mistreats homeowners having legitimate damage claims, in order to avoid responsibility for the damage, is only creating a far larger problem
(and expense) for current and future work.
|1. One contractor, an example of whose compaction work perpendicular to the street direction is shown above, damaged many homes in a road reconstruction job along two suburban streets with over
200 adjacent homes. Extensive supporting evidence of that damage and its cause was produced to the municipality and contractor in the course of litigation. The contractor, municipality and their paid "experts" repeatedly
denied any responsibility for the pervasive damage, without providing any scientifically consistent alternative explanation for its widespread and sudden appearance in many homes.
The supporting evidence produced to the municipality included: over 2000 photos of damage done to homes all along one of the two streets involved (still more taken by the contractor and an "insurance
representative" for the
municipality); 14 hours of
video showing the construction procedures used, more evidence of damage and numerous incidents of misbehavior on the part of the construction company and vibration monitoring subcontractor; nearly a hundred photos
showing the undamaged state prior to construction start of one heavily damaged home; and many other documents supportive of the claim.
Nonetheless, that contractor continued to work for the same municipality repeatedly in the ensuing years, including after a major repair had to be done (and paid for by the municipality) on that contractor's original damaging
water main work, only a few years after the work was completed. The repair site was less than a hundred feet from the location of the compaction photo shown above. It was
at one of several locations at which the original contractor had violated its own rules against pounding with an excavator bucket to break pavement. Another failure of the same general appearance occurred at the same
intersection on April 3, 2017, also repaired at the cost of the municipality's taxpayers.
The public meeting regarding the damage-producing work described above, and documented in several other places in the CVDG, was very sparsely attended by residents along the nearly 4 miles of involved streets. As it
happened, attendance would have made little difference. The contractor failed to follow several of the policies and procedures it laid out in the meeting.
A dispute between the contractor and the municipality itself, on still another job, reportedly lead to arbitration and came near to litigation. Even that did not stop the municipality from awarding a contract to that same
contractor for work on a nearby frequently traveled and highly populated street immediately after the arbitration.
Several years later, a public meeting was held to discuss
the design phase of a similar new road reconstruction project on a nearby frequently-traveled and highly populated street. That new project meeting was heavily
attended (to overflow) by nearby residents. The news of the previous, nearby, damage experience had traveled, probably due, in part, to the fact that two of the jurors in the previous damage case lived along and used the
street involved in the new project. This experience shows how vibration damage instances can change the environment for subsequent construction.
No public meeting was held to discuss that new project after the award of the construction phase contract to the same contractor involved in the previous extensive vibration damage situation, without any public discussion or mention of the
contractor's checkered history while working for that municipal sponsor. There was extensive damage documented along at least a portion of the path of this third job, involving both
homes and property walls. As photos taken a few months prior to the start of the project show, most, if not all, of the damage documented was not pre-existing.
All "effective distances" given in the CVDG should be considered as approximations, roughly appropriate for "normal" vibration propagation conditions. There is a wide variance in vibration transmission with distance, depending on
soil type, moisture, underlying rock and many other factors, even for locations the same distance from a given vibration source. In some locations with geological conditions particularly favorable to vibration transmission, the distance of concern
for possible damage can be
several miles from the vibration source. See Vibration 101 for more on this topic. The CVDG Pro goes into much more detail on this and related issues in its Vibration Safety and Calculating Vibration Amplitudes chapters, among several others.
3. For example, pile driving with vibratory ("sonic" or "resonance") pile drivers is usually both faster and generates much less vibration than hammer-type pile drivers. Compaction with newer oscillatory or
vibratory-oscillatory compactors produces less vibration for the same degree of compaction than vibratory-only compactors. A standard vibratory compactor whose vibration frequency is higher (over 40 Hz) is
likely to produce less resonant amplification of vibrations in homes and correspondingly less damage than compactors with nominal vibration frequencies below 40 Hz. While alternative equipment and methods may not be right for every job,
they should always be considered as options, especially when such operations are to be performed in close proximity (within 50 feet) to homes or other structures.
4. See, for example, Structure Response and Damage Produced by Ground Vibration From Surface Mine Blasting, USBM RI 8507, p. 72 and Construction Practices to Address Construction Vibration
and Potential Effects on Historic Buildings Adjacent to Transportation Projects report (National Cooperative Highway Research Program (NCHRP), Project 25-25 (Task 72)), p. 27, September
"Never send to know for whom the bell tolls; it tolls for thee", John Donne, Meditation 17. Many people know this Meditation better as the "no man is an island"
6. Well over 700 independent reports of damage to homes and buildings have been received by us - originating from nearly all U.S. states and territories and about 90 foreign countries. The number grows
with virtually every passing day. It is certain to be a considerable underreporting of the number of projects involved in causing damage. The number reflects only those who fill out the form to download the CVDG free version and
indicate a connection with damage,
not the larger number of those who visit and read the CVDG content on http://vibrationdamage.com.
7. To date, we have not had a single report, out of over 700 reports of damage, of a contractor, project sponsor or insurer willingly accepting responsibility for damage, no matter how much evidence may support a