not-So-pretty in pink:
deatH of a tHin-Stone veneer
lurita MCintoSh blanK, rewC, Cdt
WaLter p mOOre
and assOciates , i nc .
920 Main Street, 10th Floor, Kansas City, MO 64105
Phone: 816-701-2163 • Fax: 816-701-2200 • E-mail: [email protected]
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abStraCt
Addressing obsolete building technologies can be an unexpected and unwelcome chal­
lenge for any building owner. Façades in particular are subject to the most experimental
treatment of any building system, and thin-stone veneers are especially problematic. This
technical presentation will discuss the deterioration conditions and failures on a 1950s
thin-stone veneer; the successful and less useful techniques used to assess the veneer—
both destructive and nondestructive; and the long, frustrating progress of mock-ups, field
testing, failures, and successes needed to repair and weatherproof the exposed backup wall.
SPeaKer
Lurita mcintOsh bLank, reWc, cdt — WaLter p mOOre
and
assOciates, inc.
LURITA MCINTOSH BLANk is a materials conservator with Walter P Moore’s Diagnostics Group in
kansas City, where she is a core member of the building enclosure practice, focusing on faulty building
enclosure systems and façade restoration. She has performed dozens of assessments and investigations
into water leakage and waterproofing issues, with a specialized insight into the integration of detailing and
materials. She is also deeply involved with the Association for Preservation Technology, currently serving
on its board of directors.
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not-So-pretty in pink:
deatH of a tHin-Stone veneer
INTRODUCTION
Thin-stone veneers are not forgiving
systems. They are not “engineered” in the
sense that calculations to justify their
design are not commonly produced, and
they are failure-prone and quirky. This is
the story of the final years of the Dental
Branch Building, from the failure in 2008
that prompted the investigation to its aban­
donment in 2014. This is not a happy tale
for historic preservationists; this is not a
happy tale for architectural design enthu­
siasts; but hopefully, this is an educational
tale for professionals involved in façade
forensics and for owners of older buildings.
ed. Mackie and kamrath were selected
because their modernist designs were seen
as representing the hospital’s image as a
contemporary and technology-driven insti­
tution. Likewise, the dental school—to be
constructed in the lot adjacent to the new
hospital building—would reflect the same
contemporary values in its architectural
design.
Construction of the two buildings began
in the early 1950s. Both The M.D. Anderson
Hospital and Dental Branch buildings were
designed as twin facilities, sharing strong
horizontal massing and an emphasis on
planar surfaces, keeping true to the archi­
tects’ Wrightian influences (Figure 1). Both
buildings were clad in a stone unusual in
Houston at that time: fleuri-cut Georgia
Etowah pink marble. The new hospital was
widely lauded for both its aesthetics and
functionality; the use of the striking fleshcolored marble soon earned the building
the nickname the “Pink Palace of Healing,”
although detractors underhandedly named
it the “Pink Elephant.” In the summer of
1953, both facilities opened for use.
Over the next several decades, the suc­
cess of the M.D. Anderson Hospital trans-
formed the new Texas Medical Center into
a nationwide powerhouse for healthcare. As
a result, today, the original M.D. Anderson
building is virtually unrecognizable, relegat­
ed to a back elevation of the current M.D.
Anderson complex, almost invisible amongst
modern glass and metal curtain walls.
Meanwhile, the adjacent Dental Branch
Building remained a low-rise, stand-alone
facility, and until the mid-1980s existed in
its original form. Then in 1986, Mackie and
kamrath were again engaged to design an
expansion to the dental school. The expan­
sion to the south of the original building
maintained a similar appearance, reusing
the pink marble panels from the demolished
south elevation.
THE BIRTH OF THE PINK PALACE
Fred Mackie and karl kamrath had a
modernist vision. As faithful acolytes of
THE DANGERS OF BEING AN
the Usonian and organic architecture of
“EARLY ADOPTER”
Frank Lloyd Wright, Mackie and kamrath’s
It wasn’t only the award-winning
designs were notable for their stark lines
architectural design that made these two
and bold horizontal geometries. Relocating
buildings noteworthy. The marble façades
from Chicago to Houston in 1937, Mackie
employed a shockingly new technology that
and kamrath soon developed a reputation
was revolutionizing cladding systems world­
as a forward-thinking pair, striking for such
wide: the thin-stone veneer. According to
a young firm in an architecturally conserva­
published narratives of the building’s his­
tive environment. Through the 1940s and
tory, this was the first such application of
1950s, Mackie and kamrath prac­
ticed primarily residential archi­
tecture; but they also produced a
rapidly growing commercial port­
folio, particularly in the post-war
period, where their aesthetic could
blossom more freely than with pri­
vate commissions. In 1948, Mackie
and kamrath were awarded two
major projects within the Texas
Medical Center: the M.D. Anderson
Hospital for Cancer Research and
the University of Texas College of
Dentistry (herein called the Dental
Branch Building).
By the 1940s, the M.D.
Anderson Hospital had established
itself as an exceptional facility in
the world of healthcare, combin­
ing patient care with research
and education at a time when few Figure 1 – The east (main) elevation of the Dental Branch Building as of July 2014. Note
such multiservice facilities exist­ the remaining elevations of the original M.D. Anderson Hospital at far left.
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tion in 2008 that a full investigation into
the condition of the Georgia pink façade was
approved.
A DIAGNOSTIC APPROACH
Sometime over the weekend of July 26,
2008, seven marble panels, measuring 5 ft.
long by 2 ft. tall—nearly half a ton of stone—
detached from the south face of a setback
penthouse and crashed onto the roof of
the main building, damaging the roofing
membrane and destabilizing over a dozen
adjacent panels (Figure 2). Again, engineers
and conservators with Walter P Moore’s
Diagnostics Group responded to the site.
Based on the initial observations and dis­
cussions with the facility, a comprehensive
safety plan was initialized to provide over­
head and site safety measures for students
and staff until the entirety of the marble
façade could be thoroughly investigated.
Figure 2 – The 2008 panel failure that prompted the detailed façade assessment.
Note the domino-like effect of the failure, causing distress and failure of adjacent
panels.
a thin-stone veneer in the city of Houston,
requiring amendment of the city’s building
code to allow its use.
Façades have been subject to the most
experimental treatment of any building sys­
tem, even today employing cutting-edge
technologies and the latest material advanc­
es with little testing or empirical evidence on
the long-term performance or durability of
the systems. In the mid-twentieth century,
thin-stone veneers (façade systems using
stone panels typically less than 2 in. thick)
were a popular new system, reducing weight
and cost while allowing traditional materi­
als such as marble and granite to grace the
sleek façades of exponentially taller highrise buildings. Today, these early thin-stone
veneers are somewhat notorious for several
high-profile, well-published failures. Alvar
Aalto’s Finlandia Hall (1971) in Helsinki,
Finland, and Edward Durell Stone’s Amoco
Building (1974) in Chicago, IL, are likely
the two most infamous examples. In both
instances, the fine-grain white (Carrera)
marble veneer failed due to inadequate sup­
port of the panels and to plastic deforma­
tion of the stone; and in both instances, the
buildings required complete replacement of
the façade panels.
The lack of redundancy in the panel
anchor systems of thin-stone veneers makes
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Telling Clues in the Record Documents
Assessment of the façade began with
a detailed review of available information,
and the 1951 record drawings provided a
necessary basis for understanding the asdesigned façade system. Much like today,
midcentury architects would often only
schematically show veneer detailing, leav­
ing the specific installation methods to
be developed through shop drawings or
even installed directly in the field via the
them susceptible to seemingly spontaneous
failures, with failure of one panel negatively
affecting the stability of surrounding pan­
els. At the Dental Branch Building, panel
movement and distress had been observed
through the 1990s, and isolated locations
of through-face
pinning
had
been performed
with
brassthreaded rods
and adhesive.
Failure of several
marble panels at
decorative fins
on the east ele­
vation occurred
in 2001. At that
time, Walter P
Moore’s Diagnostics Group
was engaged to
perform some
limited
panel
stabilization and
removal at the
location of the
failure, but it
was not until a
larger failure at a Figure 3 – Gravity and lateral tie connections for marble veneer
penthouse eleva­ panels from the 1951 record documents.
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contractor’s preference. In the case
of the Dental Branch Building, the
as-designed veneer support system
was found to be in general agree­
ment with the as-built construction
(Figure 3):
1) Marble panels were shown as
7/8-in. thick.
2) Panels were supported by
angle clips at each floor line.
3) Panels were stacked panelto-panel between floors with
mortared joints.
4) Lateral support for panels
was provided by four wire
brass ties, one at approx­
imately each corner of the
panel, set in mortar pats.
Since wire ties are flexible con­
nections that would buckle under
compressive loads, the mortar parts
both provided support against nega­
tive flexure and eased leveling of the
panels during installation.
Figure 4 – Gravity support system at the 1986 addition showing the marble liner blocks
At the 1986 addition, the origi­ doweled into the backside of the veneer panel and the poor engagement of the brass
nal 7/8-in. panels were salvaged dowels (inset diagram).
and reused, although the panel sup­
port system was modified as follows
ly referred to and marketed as a “marble,” to hysteresis than others. Although hys­
(Figure 4):
Georgia pink is, in actuality, a highly crys­
teretic behavior is better documented in
1) At each floor line, panels were sup­
talline, metamorphic limestone composed fine-grained white marbles such as Carrera,
ported by marble liner blocks dow­
primarily of calcite. Trace amounts of silica, this condition has been widely observed in
eled and adhered into the verso of alumina, iron oxide, and magnesia cre­
the author’s experience in coarse-grained
the panel bearing on angle clips.
ate the fleshy color, while larger deposits and highly crystalline limestones similar
2) Panels were stacked panel-to-panel of impurities such as mica, quartz, and to Georgia pink and Georgia white. Calcite,
between floors with shims and fin­
graphite impart the bands of dark and light the main mineral component of marble,
ished with sealant joints.
that create the highly figurative and highly expands in the presence of heat and mois­
3) Lateral support for the panels was desirable striations. The Georgia pink used ture. Since calcite is anisotropic (meaning
provided by clips with pins doweled to clad the Dental Branch Building was that it expands more in one direction than
into the marble edge, one at approxi­
produced by the Georgia Marble Company another), this uneven expansion causes
mately each corner of the panel.
(now PolyCor, Inc.) and was taken from the cracks to form among the grains of the
Etowah quarry in Tate County, Georgia.
stone, weakening the marble’s strength,
Cladding designs at both the original
Marble (and metamorphic limestones), increasing its porosity, and eventually caus­
building and later addition show a con­
although brittle materials, will exhibit some ing the panel to deform into a cupped or
cerning lack of redundancy in the support plastic behavior over long periods of time. bowed shape. In its severest form, hyster­
systems. The stacked configuration of the Although eccentric and unanticipated loads esis can result in panel failure through
panels with the lack of separate gravity can certainly cause deformation in marble failed connections and unstable bearing
support for each panel readily lends itself panels, certain types of marble are also conditions.
to the type of domino-like failure observed subject to irreversible material expansion
at the penthouse elevation: When one panel in the presence of hygrothermal forces, Putting a Plan in Place
fails, failure of the panels above is the direct usually causing deformation in the form
The sheer number of panels (nearly
result, and failure of the area causes desta­
of “cupping” or “bowing” of the panels. 7,000 in total), every one of which would be
bilization of adjacent panels.
This intergranular, microscopic expansion, observed and sounded, necessitated devel­
called hysteresis, is most severe in thin- opment of a controlled and objective survey
The (In)fallibility of Stone?
stone panels with a high aspect ratio and protocol. Assessment of the Dental Branch
Another informative bit of evidence was is well-documented as a common cause of Building façades began with a systematic
material research performed on the geologic panel failure in marble veneers.
documentation of the as-built construc­
properties of the marble. Although common­
Certain marbles are more susceptible tion. Every panel at each elevation, inset,
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setback, and offset was identified, catalogued, and assigned a unique key
(i.e., NE-14-26 = north elevation, column 14, row 26) that was coupled
with a complex and scalable conditions matrix. Conditions were numeri­
cized according to extent, context, and severity; and value-based thresh­
olds for “distressed” (yellow, right-leaning hatch), “severely distressed”
(orange, left-leaning hatch), and “failed” (red, cross hatch) were estab­
lished (Figure 5). The intent of the tripartite categorization was to establish
which panels might be monitored in place, which could be stabilized in
place, and which required removal.
Figure 5 – Diagram of partial north elevation showing
results of assessment based on the distressed (yellow,
right-leaning hatch), severely distressed (orange, leftleaning hatch), and failed (red, crosshatch) categories.
The Most Important Tool
Despite the impressive arsenal of technologically advanced devices
available to the façade diagnostician, visual survey by an experienced and
knowledgeable eye remains the most important tool in the detailed assess­
ment of cladding systems. This required up-close visual observations of
each panel, enabling panel distress conditions to be documented in detail.
Observations of the marble panels established a small but welldefined glossary of typical distress conditions (Figure 6):
• Cracking (longitudinal, transversal, diagonal)
• Displacement (perpendicular to the wall plane and parallel to the
wall plane)
• Hysteretic deformation (inward cupping and outward bowing)
• Spalling at anchorage points (incipient and debonded)
The visually obvious distress conditions, particularly panel dis­
placement
and
deformation, were
severe enough to
warrant concern
about the stability
and safety of large
areas of the marble
façades. Even more
concerning to the
assessment team
was
concealed
deterioration of
panel anchorage
and support sys­
tems, which could
potentially lead
to unanticipated
panel
collapse.
At the penthouse
failure location, it
was observed that
drilled
anchor­
age points for the
brass wire ties had
instigated microfracturing of the
marble panel edge,
leading to spall­
ing and stone loss
around anchorage
points (Figure 7).
Figure 6 – Typical distress conditions: diagonal cracking (upper left), inward deformation to the point of
fracture (upper right), parallel- and perpendicular-to-wall-plane displacement (lower left), and incipient
spalling (lower right).
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Figure 8 – Relative stiffness
plot for impulse response
testing with overlay of panel
condition ratings as described
in Figure 5. Note the potential
correlation of high areas of
stiffness (darker) with the
locations of distressed panels.
Figure 7 – Spalling and visible fracturing around drill points for wire ties was
typically observed at visible anchor locations.
Sometimes You Have to Hit It With a
Hammer…
Sounding is a qualitative field test meth­
od of determining homogeneity of a mate­
rial by comparing the tone and/or vibration
generated at distressed versus undistressed
locations; it is a well-documented method of
finding cracks, voids, and delaminations in
masonry materials. For a thin-stone veneer,
sounding can be used in a modified manner
to potentially identify panels with concealed
cracking and other deterioration condi­
tions. Additionally, the “response” of the
overall panel can be used as a preliminary
identification method for panels with failed
anchorage locations, as the panel may be
overly flexible or “bouncy” when struck. At
the Dental Branch Building, sounding was
performed with the plastic end of a 12-oz.
double-faced soft hammer.
At the 1951 building, the mortar pats
installed around the wire ties for panel
leveling were found to be highly friable and
would disintegrate when struck, eliminating
what little in-plane resistance to movement
that had been provided by the mortar. At
the 1986 addition, the marble liner blocks
debonded during sounding and fell into the
wall cavity; by examining the marble liner
blocks, it was discovered that the brass pins
set in adhesive used to connect the blocks
to the backside of the panel did not extend
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through the block into the body of the
panel, leaving only the adhesive to transfer
the gravity load to the clip angles. The adhe­
sive had failed, and panels at the 1986 addi­
tion were likely unrelieved for the full six
stories, held in place by only the lateral ties.
…But Maybe That Hammer Could Be
Calibrated?
In addition to the qualitative method
of sounding panels, testing was attempted
to determine if panel flexibility related to
anchorage failure could be quantitatively
evaluated. Impulse response is a nonde­
structive technique used to evaluate the
integrity of panel elements and connections.
A low-strain impact using a small ham­
mer with a built-in load cell is applied to
excite the element (the panel). The response
(vibration) of the element is monitored by a
velocity transducer (geophone) placed adja­
cent to the impact location. The hammer
and the geophone are connected to a data
acquisition and processing system, which
calculates the dynamic mobility as a func­
tion of the frequency of the excitation. The
dynamic mobility is analyzed to character­
ize the support conditions and the dynamic
stiffness.
In theory, based on the analysis of the
dynamic mobility plot, locations of dete­
riorated connections may be identified. In
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Figure 9 – Borescope observation
locations showing openings in stone
adjacent to connection locations. The
dashed line indicates location of the
mortar pat around the clip angle
connection.
Figure 10 – Implementation of
the “hybrid” repair approach at a
Georgia white marble thin-stone
veneer. The existing stone panel
was pinned in place with stainless­
steel-threaded rod and epoxy
adhesive (left); the adjacent panel
was removed (right). An elastomeric
coating and flashings were applied
to the exposed backup wall to
provide additional weatherproofing
and improved aesthetics where
panels were permanently removed.
practice, stiffness of the panels was gener­
ally measured to be low in nearly all loca­
tions, with only isolated areas of compara­
tively high stiffness values. Interestingly,
these locations of high stiffness appeared
to somewhat correspond to locations of
in-plane displacements of panels, perhaps
indicating excessive stacking of panels due
to anchorage failures (Figure 8). The low
average stiffness can be attributed to the
unsupported nature of the panels between
anchorage points and the flexibility of wire
ties. Failure of mortar pats and lateral
ties could perhaps also be considered as
contributing to overall failure. In all, the
impulse response test results were interest­
ing but inconclusive.
A View in the Dark
Based on the findings of the visual
observations and the conditions discov­
ered during the panel sounding, borescope
observations were performed in an attempt
to view the undisturbed panel connection
conditions from inside the exterior wall cav­
ity. Given the extreme shallowness of the
cavity (½ in. or less in many locations), it
was necessary to create small viewing open­
ings through the face of the stone (Figure
9). The decision to limit panel removal and
to create such small viewing openings was
partially driven by the discovery that the
existing mastic damp-proofing contained
asbestos fibers.
Rough connection locations were iden­
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tified by sound­
ing and were veri­
fied with surfacepenetrating radar
(SPR). Cores were
made through the
stone; and a flex­
ible, fiber-optic,
self-lighted camera
was inserted into
the cavity. At both
the original build­
ing and the later
addition,
spac­
ing of the lateral
ties was found to
be variable; and
concealed spall­
ing was observed
at the backside
of the gravity and
lateral
connec­
tions. Lateral ties
at outside corners
were observed to
be missing or not
engaged in the
panel, contribut­
ing to the splaying
displacement observed at building corners.
Synthesizing the Findings
Based on the results of the visual sur­
vey, sounding, and nondestructive evalu­
ation methods, the panel condition matrix
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was used to determine that building-wide,
over 25% of panels were rated as distressed;
nearly 5% as severely distressed; and nearly
5% as failed, with distressed or failed areas
rarely observed as single panels but more
commonly occurring as clusters of dis­
Building EnvElopE TEchnology • ocToBEr 2014
tressed veneer. With approximately
35-40% of the entire façade system
exhibiting deterioration or distress,
discussions on the merits of in-situ
stabilization versus demolition of the
façade system began.
STAGING AN INTERVENTION
VS. THE COST OF DIMINISHING
RETURNS
Deciding on the appropriate
level of intervention to address life
safety concerns—balanced against
construction cost, expected facility
service life, and disruptions to the
dental school—was not a simple met­
ric. With the congestion of the medi­
cal center and significant construc­
tion ongoing at adjacent lots, closure
of driving lanes and access alleys
could not occur during repair work
at the Dental Branch Building. Work
would need to be limited to the con­
straints of the site while the building
remained in full operation and park­ Figure 11 – TPO weatherproofing membrane mock-up in progress, showing wrinkles in
ing remained accessible. Because the membrane and installation issues.
dental school was in the midst of
constructing a new facility off-site, it was projects, particularly where rapid response waterproofing sheets. At the time of the
anticipated that in approximately five years, in the event of an emergency situation pre­
application of the asphaltic damp-proofing,
the Dental Branch Building would be vacant ceded funding or availability of materials for the design intent at the 1986 addition was
and ultimately demolished, making way for full-scale repairs.
to install a custom-tinted thermoplastic
new construction. Although arguably an
polyolefin (TPO) membrane to the vertical
important example of mid-century mod­
Primers and Sheets and Coatings…
surfaces to act inclusively as additional
ern architecture by an important Houston Oh My!
weatherproofing, protection against ultra­
architectural firm, it was not a registered
In execution, stabilization-in-place violet radiation, and the aesthetic wall finish
landmark and enjoyed no local, state, or proved a far easier challenge to tackle (Figure 11).
federal protection against demolition or than the problem of how to address the
From the initial mock-up, issues arose
modification.
now-exposed mastic damp-proofing at the with the TPO membrane. Wrinkles in the
1986 addition. The existing damp-proofing membrane resulting from being rolled dur­
The Plan of Attack
was discovered under laboratory analy­
ing the manufacturing process could not be
A hybrid system of demolition, stabi­
sis to have asbestos-reinforcing fibers and smoothed, and the last several feet of each
lization in place, and monitoring in place was classified as a Category II, nonfriable sheet had to be discarded because of severe
was developed to address various locations asbestos-containing material (ACM), mean­
wrinkling. Application issues were encoun­
across the building (Figure 10). The marble ing that while the asbestos content was tered as well; installing the membrane on
cladding at the 1986 addition, where the above the minimum allowable level set by a vertical wall in a smooth, unblistered
gravity connections had likely failed, was the EPA, there was minimal opportunity application with no fishmouths or wrinkles
removed in its entirety; while panels at for exposure of workers or occupants to at seams proved excessively labor-intensive
the 1951 building were removed, stabilized hazardous materials. However, the existing yet still produced aesthetic results unac­
in place, or left in place and monitored, damp-proofing could not remain exposed ceptable to the facility. Additionally, adhe­
depending on the location and proximity due to its sensitivity to ultraviolet radiation. sive failure of the membrane to the dampto building entries. This hybrid approach
First, the ACM damp-proofing was proofing repeatedly occurred at very lowwas developed so that repair could be com­
encapsulated in place using a spray-applied, tensile strengths, even when the surface
pleted in both a cost- and schedule-efficient emulsified, water-based asphaltic damp- was allowed to cure and was primed accord­
manner, while fully addressing overhead proofing. This product was selected because ing to the TPO manufacturer’s require­
hazards and providing repairs of sufficient of its improved waterproofing capabilities, ments. After several unsuccessful mockdurability to outlast the expected service its adhesive compatibility with the existing ups, much research, and more frustration,
life of the building. This approach has been damp-proofing, and its purported suitabil­
the plan to use a polymer weatherproofing
successfully implemented at several similar ity as a substrate for various self-adhering sheet was abandoned.
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Figure 12 – Mock-ups of elastomeric coatings, showing asphaltbleed issues (inset).
Consultation began with several elasto­
meric coating manufacturers in order to find
a coating adhesively and chemically compat­
ible with the asphaltic damp-proofing. Six
products—all acrylic or silicone high-build
elastomeric coatings—were selected for an
initial mock-up phase. All six proved to have
asphalt-bleed issues, causing discoloration
and failure of the coating (Figure 12).
Finally, after several mock-up applica­
tions, a coating was found that resisted
bleed-through of the asphalt and provided
acceptable adhesive strength to the dampproofing. Unfortunately, after five years
of field service, the coating has not aged
well; excessive pinholing, shrinkage, and
tearing of the coating were observed dur­
ing the author’s site visit in July 2014
(Figure 13).
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AUTHOR’S NOTE
As of mid-July 2014,
the
Dental
Branch
Building sits empty, aban­
doned by the dental school
for its new facility, and is
awaiting demolition. The
site is cordoned off with
security fencing, looking
very much unused and Figure 13 – Aging of the elastomeric coating,
unloved. Ultimately, the showing failure of the coating and exposure of the
temporary stabilization underlying damp-proofing.
and weatherproofing mea­
sures employed served their purpose: to assessing and stabilizing what was, at its
keep the building safe and leak-free through inception six decades ago, a state-of-thethe short remainder of its operational ser­
art façade system, but what is now a sadly
vice life.
out-of-date liability—presented a singular
Following the declination and death of challenge for adapting knowledge and tools
this building was a challenging experience, better suited for more modern systems.
both intellectually and technically. From
The lessons drawn from this project are
a technical standpoint, the challenges of legion. Foremost is the importance of assem-
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bling a strong project team. No nondestruc­
tive evaluation method to date, no matter
how sophisticated, can replace the contribu­
tions of a knowledgeable façade consultant,
experienced in the idiosyncrasies of an early
thin-stone veneer system. Although assess­
ment of these systems relies somewhat on
more qualitative than quantitative methods,
it is possible to establish a condition-based
matrix against which to measure the condi­
tion of individual panels and larger façade
areas as a whole. Furthermore, evaluating
concealed conditions at anchorage points is
critical to a thorough understanding of the
stability of the veneer system; essentially,
looks can be deceiving, and it is necessary
and proper to conduct a more detailed and
invasive investigation. With façade systems
of this nature, having little redundancy
against failure and a tendency to foster
hidden deterioration conditions, a respon­
sible façade consultant can successfully
guide an inexperienced client through the
potential dangers, numerous liabilities, and
complicated repair options, ending with a
successful execution based on the situation
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and needs of the project-specific conditions.
In the case of the Dental Branch Building,
it was not a “happily-ever-after” ending.
Hopefully, the information gathered during
the assessment and the stabilization will
inform future practitioners.
ACKNOWLEDGEMENTS
It is a folly to assume that a project
of this complexity could be accomplished
without the substantial support of a learned
and dedicated group of people. I would like
to thank my colleagues at Walter P Moore
and associated contractors for their hard
work through the extreme heat and humid­
ity of August in Houston, as well as the
University of Texas Health Science Center
for its willingness to share the story of this
unique building.
REFERENCES
ASTM (2005). Standard Guide for
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C1242-05. West Conshohocken, PA:
ASTM International.
B u i l d i n g E n v E l o p E T E c h n o l o g y • o c T o B E r 2 0 1 4
C. Borgal (2001) “Thin-Stone Systems:
Conflicts Between Reality and
Expectations.” APT Bulletin, 32 (1).
pp. 19-25.
F.C. Elliott (2004). The Birth of the Texas
Medical Center: A Personal Account.
W. H. keller (ed.). College Station,
TX: Texas A&M University Press.
P. Loughran (2007). Failed Stone. Basel,
Switzerland: Birkhäuser Verlag.
S.R. Miller (1993). The Architecture of
Mackie and Kamrath. (Unpublished
master’s thesis). Houston, Texas:
Rice University.
D. Hester et al. (2009). “Thin Marble
Facades: History, Evaluation, and
Maintenance.” RCI Building Envelope
Technology Symposium Proceedings.
Raleigh, NC: RCI, Inc. pp. 55-66.
M.J. Scheffler (2001). Thin-Stone Veneer
Building Façades: Evolution and
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