Although vibration damage to structures is usually described in terms of "cosmetic" and
"structural" types, understanding the specific kinds of damage which can occur, their
causes, their implications and how to address them is essential both to establishing and pursuing a construction vibration
damage claim. On this page we'll give some tips, with illustrations, of how to
recognize the various types of damage.
This document is part of the free Construction Vibration Damage Guide for Homeowners, available in part online or in full as a
free downloadable PDF, minus ads and navigation and with substantial added content. An Executive Summary is available for those in a
hurry. A broader view of its content can be found on its Introduction page.
Appendix B of the CVDG, available in the free downloadable PDF version of the CVDG and in the CVDG Professional Edition, but not online, has a compilation of
warning signs of possible construction-related vibration damage. This should help you in searching for and identifying possible damage.
Most people don't go through their homes with any care or regularity looking for signs of vibration or other damage. Vibration damage
can involve drywall or plaster cracking or other forms of distress for which you will have to look in order to
note it. In our experience, it is the rule, rather than the exception, that
homeowners with construction vibration damage will feel they have no damage from
the nearby construction, until they look for it with an eye to the specific and
diagnostic types of damage that are discussed below. A few small hairline cracks in drywall or plaster are not, by themselves, cause for concern about nearby construction damage. More than ten or so, of any size, constitute good reason to investigate further and
Possible "Structural Damage" Indicators
"Structural" vibration damage is best evaluated by a civil or structural
engineer with experience in viewing and evaluating such damage. If you make a
claim, whether or not you have to litigate it, it's a good bet that the
construction company or their insurer will want to send an engineer to evaluate
the house for structural damage. Since that engineer works for the opposing
side, you may or may not get straight answers, but you can express your
concerns about specific types of damage and sites to the engineer for his opinion and evaluation. Eventually, you may
have to bring in your own engineer for a second opinion.
In multiple discussions with engineers about vibration damage,
I have learned that there are some simple signs to look for that might indicate that you
should have an engineer check for underlying
structural damage: (Click each thumbnail to view the full-sized image)
in the house slab or connected patios and driveways - These may not
constitute structural damage; but, if they are not pre-existing, they are
signs that should be discussed with an engineer in the context of structural
damage to the house. Cracks in tile or grout can reflect cracks in the
underlying slab. To the extent that the house slab and/or patios are
monolithic pours (connected together and poured at the same time), information in
the blasting vibration study
RI 8507 indicates that such cracks, if caused by construction, result from vibrations far in excess
of any U.S. standards.3 Our CVDG Pro page, Inferring Vibration
Levels, has more
information on inferring vibration levels from damage patterns.
doors and windows - Misalignment can be seen by looking at the door in
the frame. If the door doesn't show a reasonably constant spacing all the
way around between it and the frame, it has become misaligned. Some doors
and windows may become difficult or impossible to open or lock, if the misalignment is large
enough. Windows may become difficult to operate when misaligned. If you also
see diagonal drywall cracks at corners of window and door wall penetrations
(see below), these are additional signs that the house has undergone shear, possibly
due to vibration, which is causing the misalignment. Checking the door and
windows frames for plumb, using a level, can strengthen an argument that the
house structure has shifted in response to construction vibration. Misalignment may also appear in plumbed (vertical) fixtures (TV mountings, shelving, e.g.) attached to the wall studs.
- Mechanical system problems - If you suddenly start to experience plumbing failures
underground (e.g. irrigation or waste line pipe shattered) or at the point
where the house supply connects at the slab to the incoming line from the street,
especially in the context of other vibration damage, it may be an indicator
of possible structural damage. Problems with any other lines which go
underground (heating, gas, etc.) may also indicate the possibility for
structural damage. Damage to irrigation system solenoid valves can also occur due to very large construction vibrations. If you have such mechanical system damage, there is a very good chance
that others nearby will have it, too, so keep your eye out for plumbing and heating firm trucks in your area.
- Cracks in dry wall with vertical displacements - Most cracks in
drywall are considered as "cosmetic" in nature. However, if you have cracks in
which one side of the crack is substantially higher than the other side,
this could be a sign of underlying structural damage. Also, any crack in
drywall in which the failure is not along a join between sheets, but in the
sheet itself, especially if it is jagged in appearance, may indicate a possible
underlying structural issue requiring further investigation. (photo below)
- Roof damage - Shingled roofs will usually show little sign of
damage from vibration to the underlying trusses, because the shingles can
hide it, although roof leaks are sometimes signs of otherwise invisible damage. However, tiled roofs have penetrations which are usually sealed
with concrete "cones". If these are broken, it could be a sign of structural
problems. Usually breaks in the cones result in water leaks, which are also
signs of potential structural problems in buildings with shingled roofs.
Many houses beyond ten or fifteen years in age will have a few (less than
ten) hairline cracks along drywall seams and/or at drywall corner beads, due to slight
settling, changes in temperature and humidity, or simple aging of the drywall. Most times, the residents of the house will not even be aware that
these are present, because they are usually hairline cracks which are not easy to see, unless one sets out to find
them.8 Once people find such cracks, they can become more sensitized to them and look
others. The possible existence of unseen, pre-existing cracks is well-recognized, both in the
scientific literature of ground vibration damage and by contractors. For this
reason, you will almost certainly hear that your damages were all pre-existing
and that you had simply not seen them in the past.
Because limited minor cracking can occur for reasons other than construction
vibration, the timing of the damage is important in connecting it to the
construction work. On the occasion of our damage, the witnessed and videotaped construction vibration
produced over 300 immediate cracks, plus damage to concrete block property walls and a monolithic
poured concrete patio, in one day! Additional cracking
appeared later, as the job continued over strenuous objections from me and
others whose houses had been seriously damaged by the same construction.
When looking at your home for
"cosmetic" cracks (either before or after start of construction work), here are some locations you should check and ways to
begin to differentiate vibration cracks from settling (or aging) cracks:
hairline drywall cracks at corner beads and at sheet joins - These are
common in both settling and vibration damage. They take on a nearly line-like appearance, as the crack is directed along the corner bead edge or sheet join. Mostly, the cause can be
differentiated only by the timing of appearance and the number of cracks
which appear in connection with construction. In my experience,
vibration-related cracks tend to be longer and more numerous than those
caused by settling. They also tend to expand with time. Because settling and vibration cracks of this sort look
so similar, documentation of the time and circumstances of their appearance
- Diagonal cracks at corners of wall penetrations (windows, doors,
etc.) - There
are some characteristics of vibration cracks which settling cracks
rarely share. Cracks at drywall corner beads and sheet joins can
occur from normal settling, temperature cycling and construction vibration. However, cosmetic
drywall cracks from vibration often appear at the corners of
windows and doors, running roughly diagonally from the corners.
Corresponding cracks often manifest themselves outside around wall penetrations in rigid finishes like stucco.
These diagonal cracks are due to the house being placed in shear (i.e.
sections of the house moving in different directions or speeds with respect to one another) by
vibrations. These shearing vibrations are known in the field as "racking"
motions (see Figure 13 in USBM RI 85071). They are different in nature and consequences from the so-called
"mid-wall" vibrations ("bending") which lead to pictures rattling on vibrating walls,
although racking and bending motions often occur together. Such racking cracks rarely appear house-wide in normal uniform settling and are often
indicative of vibration damage, especially when seen in multiple structures
in a given neighborhood.
- Drywall nail or screw "pops" - These appear as places where the
"mudding" over the screw or nail is either raised, has multiple small
radiating cracks or is missing entirely (see photo at left). If
widespread and significant in number, they also imply shear forces, likely due to vibration.
in drywall with vertical edge-to-edge displacements - As discussed
above, these cracks often appear in situations in which the house has been
subjected to shear, due to vibrations. The vertical displacements (i.e. with
one side of the crack substantially higher than the opposing side) are
indicative of the shear process and may signify some shifting in the frame
of the house.
to exterior finishes - Just as vibration damages drywall, it will also
usually cause cracks in exterior rigid finishes like stucco. Cracks in
stucco running diagonally from wall penetrations are indicative of
vibration-induced shear, just as they are in interior drywall.
in exterior property walls - Particularly in the U.S. Southwest, exterior concrete block
"tumbleweed walls" are common dividers at property lines. These are also
damaged by extreme vibration. This damage can take the form of both cracks in
mortar or cracks in the blocks themselves.
Cracking of concrete - Similarly, there can be cracking in monolithic (poured at the same time) concrete
slabs, driveways or patios (see at right for example of construction-caused slab cracking).
As discussed in the
study, RI 8507, cracks in monolithic concrete, mortar or blocks can be good indicators of the intensity of the vibrations2, since it requires vibration intensities
well above any standard in the U.S. to break mortar, concrete blocks or
The OSM also provides guidance on these matters in its Blasting
- "Cracks will not normally appear in concrete
below perhaps 10.0 inches per second, a velocity that is not only far
higher than OSMRE regulations permit, but that would normally cause
undisputed and quite extensive cracks to occur to plaster, gypsumboard
and brickwork. Damage to concrete is therefore normally accompanied
not only by exceptionally high velocities, but also by other, and
obvious damage." (emphasis added)
The OSMRE Blasting Guidance Manual provides substantial advice, very similar
to that offered here, for identifying damage and associating it with vibration
events.4 The CVDG Pro page, Inferring Vibration Levels, has more
information on inferring vibration levels from damage patterns.
Other Property Damage Causes
Construction may cause damage for reasons other than vibration, per se.
Breakage of gas or water mains (e.g. see video frame capture of a flooded street from a construction-broken water main at left7) can lead to damage to property that will require
fixing. If any excavation must be done on your property to further the
construction (e.g. connecting meters to water mains), that is sometimes poorly cleaned up, if at all. If you have damage
of these types, they should be included in your damage repair claim.
The types of damage seen here may continue to appear for many months after
the construction ends. Most engineers advise waiting at least six months
before fixing any construction damage. The reason for this is that the
adjustment of the home to stresses placed on it by the vibrations isn't
fully completed when construction or vibration ends. At right is shown a diagonal construction vibration-caused crack beginning at the wall penetration corner at the lower right of the photo. Its length was marked by the contractor's engineer "expert" the next business day after this damage was done,
resulting from pounding on pavement with an excavator. Extension of the crack over time well beyond the initial marking is clearly visible in the photo.
Thus, you may continue to have newly appearing or worsening damage
after construction is finished. Such worsening of damage
doesn't necessarily mean the house is experiencing damage from some new source.
It may be just the slow resolution of the underlying stresses brought about by the
construction vibration. In my case, it was well over a year after construction end
that damage mostly stabilized.
People sometimes come home from work and find damage that they think is new, which they attribute to nearby construction. Only occasionally are the damaging events or operations witnessed while the damage is occurring. Time of damage onset is usually vital to establishing causation. It is often estimated in litigation contexts by "experts", based on appearance of crack edges, using
assumptions and judgments which are scientifically questionable.
For example, the paired photos above show the same
drywall crack 3 days after creation (top - early in the construction job) and 139 days later (bottom - 37 days after end of the construction work at this location). There is no difference in the shared portions of the crack edges discernible to the naked eye, in spite
of the relatively long period between the photos and some extension of the crack with continued construction vibration. Thus, any meaningful deductions about the timing of this well-documented crack based on its aging with time are
impossible by mere visual inspection.9 The hazards of estimating crack timing by inspection, with additional examples in different types of building materials, are discussed in more detail in the CVDG Pro's chapter, Estimating Damage Age. Documentation as close to the time of
crack formation as possible is the best way to protect
yourself against such unsupportable opinions.
Construction almost invariably results in noise issues ranging from minor
discomfort, to, in extreme cases, potential health issues. While noise issues
are outside the scope of the CVDG, homeowners should be aware of their possible
contributions to nuisance and inconvenience during the construction. The FTA
Noise and Vibration Manual has extensive information on noise impacts that
homeowners may need to read. Vibration monitoring equipment has the capability to record sound as well as ground vibration, so any vibration monitoring done will often include sound data (see photo at left for an example setup
including a microphone for sound measurement).
Talking with Neighbors
If you see significant damage appear suddenly, during a construction job adjacent to or nearby your home (within hearing distance),10 you should talk with your immediate neighbors about any damage they might have. If only one house is damaged, the
construction contractor can blame the damage on the house or you; if several are damaged that argument gets increasingly difficult to sustain. Chances are, your neighbors will not have looked for damage nor will they know of any,
so you will probably have to tell them what to look for in their own houses. Seeing and documenting the damage is not difficult, once you know where to look and how damage appears. The CVDG will help you and them know for what they should search.
Your neighbors may also have a better idea of what was actually done during the
construction, if they are at home during normal construction working hours. Learning from neighbors and documenting damage in
their homes is a crucial issue which is discussed in more detail on our page,
This is, by no means, an exhaustive listing of all the kinds of vibration
damage which can occur. Instead, I suggest it as a starting point for those who
may feel that they have construction vibration damage and want to know for what
they might look to find.
|1. Structure Response and Damage Produced by Ground Vibration From Surface Mine Blasting, USBM RI 8507, p. 18
2. Ibid., p. 44
3. Ibid., p. 45
4. OSMRE Blasting Guidance Manual, pp. 121-122
5. OSMRE Blasting Guidance Manual, p. 121
6. "When major, structural damage, such as the collapse of brickwork,
extensive and serious cracking threatening structural integrity, or
concrete cracking is found (apart from the small drying-out or
temperature cracks to be found in virtually all concrete) then either
the ground motion exceeded 3 or 4 inches per second, or some other
reason exists for the damage." OSMRE Blasting Guidance Manual, p. 112
7. The contractor who created the flooded street shown in the photo, by breaking a water main, broke another water line literally in front of the author. This occurred on January 3, 2017 in a new project a few blocks away in which the same
contractor was performing a water main replacement and road reconstruction, very similar to the job referenced several times in the CVDG. The author documented the ongoing break, which was confined within a large, deep
hole dug to access the line, with a cell phone camera.
8. Cracks in drywall become more difficult to see under conditions of high humidity. The humidity is absorbed by the drywall. It swells slightly, closing the cracks. For this reason, it is often best to look for cracking
in the winter, when the humidity in most homes tends to be lower.
9. Viewing this well-documented crack, plaintiffs' experts said, correctly, that it was recent and caused by construction. Defendants' experts said that it was old and pre-existing. Neither conclusion was scientifically justifiable
based on inspection of the crack alone.
10. Effective distances for construction vibration given throughout the CVDG are guidelines only, as both sound and ground vibration can travel differently in materials and environments. These approximations are given for
those who don't seismographic data on the vibrations available to them.
This is a chapter from the Construction
Vibration Damage Guide for Homeowners (CVDG), a 100+ page free
document with over 200 color photos, diagrams and other illustrations.
It is available at
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