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masonryedge.com44 MASONRY EDG E / thestorypole 2011 Vol 6 No 2 Masonry’s Added Value
Beaubien House, originally built as a residence in 1851,
is listed on the National Register of Historic Places and is home
to The American Institute of Architects (AIA) Michigan and
Detroit Chapters. Its three-story reddish-orange brick walls are
comprised of three wythes of brick supported by a fieldstone
foundation wall. Designed in the Italianate Townhouse style, Beaubien
House is one of the oldest remaining buildings in downtown Detroit.
Situated at 553 East Jefferson Avenue, a major east-west artery into
the city that runs parallel to the Detroit River, the historic building was
purchased by AIA in the 1980s, demonstrating to the architectural
community the importance of a presence in Detroit and maintaining
relevant historic architecture. Multiple renovations and restorations
have taken place over the years with the most significant renovation
completed in 1987 by the AIA. Its structure remains in good condition
with little settlement. Overall, the brick façade is still in excellent
condition, although the history of repairs has created a patchwork
of various mortar colors and types, with some brick replaced with
a pigmented concrete patching mixture.
Creating a Plan SmithGroup’s Building Technology Studio
(SmithGroup) has been an active participant in designing and implement -
ing renovations and repairs to the modest seven room Beaubien House
over the past eight years. In the fall of 2009, SmithGroup met with Rae
Dumke, then executive director of AIA Michigan/Detroit, Dan Zechmeister,
executive director of the Masonry Institute of Michigan (MIM), and Bob
Henderson, project manager with Detroit mason contractor Dixon Inc, to
evaluate repair and restoration needs. The East elevation was deteriorating
due to years of water draining onto the face from a neighboring roof.
Immediate repairs were required.Many brick faces in that location had
deteriorated, mortar joints were soft, with evidence of former incorrect
repointing work. At that time it was decided that a plan for future repairs
was required. This plan would
include a survey of the exterior
façade, recording of former
known repairs, identification of
future repairs prioritized and
organized on a timeline and
identification of a mortar mix
design and matching brick. This
would minimize investigative
work in the future and create a
uniform program for masonry
repairs. Most importantly, it
would also help AIA plan and
budget for future repairs.
PetrographicAnalysis Because there
were no written records containing details of previous repairs, SmithGroup determined
that the process of brick and mortar repairs needed to start at the beginning. The first
step was to remove mortar from the building to analyze it for composition. For buildings
from the 1850s, the mortar was most likely lime-based, but the analysis would tell for
certain. The key in removing mortar is to remove it from deep enough in the wall to
ensure samples are not of newer repointing mortar. In this case, multiple brick were
removed and samples were taken from within the barrier-type masonry wall. Both brick
and mortar were sent to the laboratory for analysis.
Imag
e cou
rtesy
of W
ikim
edia
and
Andr
ew Ja
mes
on
Beaubien House DetroitAIA Michigan & AIA Detroit headquartersThis work was made possible by the volunteer efforts and donation of services and materials, with sincere appreciation and thanks, by the following companies.
Architectural Services SMITHGROUP Detroit
Petrographic Analysis WISS, JANNEY, ELSTNER ASSOCIATESNorthbrook, IL
Mason Contractor DIXON INC Detroit
Masonry Services and Material Procurement Salvaged Brick GAVIN HISTORICAL BRICKSPlasterer's Sand MARSACK SAND AND GRAVELLime Cement NATIONAL BLOCKMasonry Cleaner DJ BARRON
Beaubien House Case Study:
PROACTIVE
APPROACH TO
MASONRY
PRESERVATION
Necessary for Extending a Building’s Life
by Meredith Steckling, AIA, CDT,
LEED Green Associate
Preparing a plan for masonry maintenance and repairwill keep Beaubien House in continuous service and willsave AIA Michigan, the owner, money over the long run.
Beaubien House_Final_ME-SP Vol6_No1 7/15/11 12:58 PM Page 44
masonryedge.com Masonry’s Added Value 2011 Vol 6 No 2 MASONRY EDG E / the storypole 45
Laboratory analysis can vary by type and, there fore, cost.
There are two tests generally performed: petrography and
chemistry (both were used for Beaubien House) For
petrography, the cost may run from $300 to $1,600. For
petrography and chemistry tests combined, the range is
approximately $800 to $3,000. The range of prices may also
be related to the expertise of the person analyzing the
results. In this case, a less expensive test may not yield the
same results as a more expensive one.
Wiss, Janney, Elstner Associates performed a petrographic
and chemical analysis of the mortar for its exact
composition (see sidebar, p 46). While waiting for the
results, SmithGroup performed an at-home mortar analysis
based upon instructions from the article Selecting Mortar
for Historic Preservation Projects1. The article stated that
lime-based or cement-based mortar composition could be
determined by dissolving a pulverized mortar sample in
muriatic acid. If the foam generated was amber in color, it
indicated a lime-based mortar. If the foam generated was
green, it was a cement-based mortar. After performing
the experiment, the foam generated appeared to be a
yellow color, indicating a lime-based mortar. Another
useful result of the experiment was that after the acid was
washed away, the aggregate remained. The aggregate
was given to the contractor who was more easily able to
match the new sand to the existing by eye, as well as
by the results of the petrographic analysis.
Beaubien House Mortar MixResults Petrographic analysis describes the
samples, analysis process and results. The most valuable
information provided to the mason matching the mortar
mix was the aggregate size, aggregate composition and
the hydrated lime-to-aggregate ratio. In this case, the
mortar mix was sanded, with a 1:2 3/4 lime to aggregate
ratio. Results also indicated that the mortar was a
hydrated lime-siliceous sand mortar. It included the ratio
of sand to lime, which was imperative for creating the new
mortar mix. It described the sand’s mineral compositions
and sizes that were used, which is helpful for duplicating
the mortar and is more specific than visually comparing the
sand to the aggregates gained from the muriatic acid test.
Historic Brick Procurement It is unknown whether the brick used in
Beaubien House was locally made. There
are buildings throughout Detroit that
appear to have been built with similar
brick, therefore there was a chance that
a match could be found from locally
salvaged brick.
At-home mortar analysis was performed by dissolving a pulverized mortar sample
in muriatic acid to determine cementitious composition.
1Sickels-Taves, Lauren B. “Selecting Mortarfor Historic Preservation Projects” Masonry Construction October 1, 1997.
Phot
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Smith
Grou
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Restoration Team Experience Since 1978
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Beaubien House_Final_ME-SP Vol6_No1 7/15/11 12:58 PM Page 45
masonryedge.com46 MASONRY EDG E / thestorypole 2011 Vol 6 No 2 Masonry’s Added Value
Deteriorated wall shows evidence of water damage from a neighboring roof’s runoff and of soft mortar joints, the result of improper pointing work performed in the past.
Henderson took brick samples
from the Beaubien House and
attempted to find a match at multiple local brick salvage yards to no avail.
When replacing a small number of brick within a large wall surface, it is
most desirable to obtain brick of the same era. If new brick are used, there
is a period after the brick are fired where the brick can expand as they
absorb water lost during the firing process. This growth can be
accommodated by weathering the brick prior to installation, but it is not as
desirable as if salvaged brick can be found. Creating new brick to match
existing may also be cost prohibitive with a small repair; salvaged brick is
more economical.
A match was eventually obtained in Iowa with brick salvaged from First
State Bank in Lineville. The bank was demolished, Gavin Historical Bricks
stockpiled the brick for resale. Beaubien House repairs required fewer than
250 brick, but due to the nature of salvaged brick, the order was increased
to 1,000. An additional 500 brick were donated by Gavin Historical Bricks.
Remaining brick will be stored for future need; however, once the supply
is exhausted, another search will be necessary. With salvaged brick, it is
likely that many won’t match in color or will be otherwise compromised;
therefore, hand selection for color and quality is necessary when selecting
brick for rebuilding walls.
The brick arrived on pallets with many of the units damaged due to the
demolition process while others appeared to have deteriorated due to long
exposure to weather. Brick was hand selected to be used in both the
mockups and for the replacement of damaged brick in the Beaubien House.
Mortar Design For a successful mortar match, multiple mockup
panels may be necessary to match both color and texture. This mortar
mixture was created per the petrographic analysis test results. Sand was
put through a sieve for granule size; grains larger than those found in the
mortar analysis were left in the sieve and discarded. The first mockups were
made for general consistency and color. The lime-based mortar, matched
to the existing for hardness, was much whiter than a standard cement-
based mortar. A decision to tint the mortar was made to more closely
match the existing weathered mortar. Without tinting, repairs would be
obvious for several years until natural dirt accumulated. Tooling methods
were also addressed to more closely match weathered mortar joints. A
typical concave joint would also affect the final appearance making the
repairs more apparent. The joints were finished to match existing.
With color in mind, portions of the remaining wall were brushed with
a mild masonry cleaner. New mockups were tinted to match the newly
cleaned mortar joints. The team experi mented using tan, grey and black
pigments to determine the best match. For longe vity, an integral black
inorganic pigment was selected, rather than a surface-applied tint.
Phot
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Beaubien House
Petrographic Analysis of Historic Mortars
The Art and Science of the Match Historically, mortars were not prepared
to narrowly defined specifications. These mortars usually
incorpo rated locally derived materials and relied heavily on the
experience of the mason to produce a good quality mortar.
Today, compositional analyses of historic mortars are most often
performed to aid in formulating a replacement or repair mortar
that is compatible with the original mortar. Installation of an
improperly formulated replacement or repair mortar could
irreparably damage historic masonry. Compositional analyses
are performed in accordance with the standard test method,
ASTM C1324, Test Method for Examination and Analysis of Hardened
Masonry Mortar, which requires petrographic examination and
chemical methods of analysis.
Mortar analysis must begin with a thorough petrographic
examination to identify constituents of the fine aggregate and
paste/binder system, evaluate the air-void system (entrained or
non-air entrained) and estimate air content. Thin-section
microscopy is preferred because it allows for easier and more
precise identification of constituents and because the thin
section preserves the condition of the mortar and the relation -
ships between mortar constituents. Poor condition of the
mortar, especially extensive alteration, can adversely affect
chemical analysis. In some cases, chemical analyses cannot be
performed so the petrographic description of the mortar
provides an approximate analysis of its composition.
The chemical analysis portion of the test method combines wet-
chemical methods and instrumental analysis to determine the
crystalline components, soluble silica, calcium oxide, magnesium
oxide, magnesium hydroxide, insoluble residue and losses on
ignition. The total of insoluble residue, soluble components and
loss on ignition should be close to 100%. If it is, the chemist
calculates the mortar proportions in accordance with ASTM
C1324. If the total is more than 5% greater or less than 100%, the
possibility of interferences or biases should be examined. Mortar
compositional analysis relies heavily on the experience of the
petrographer and chemist to recognize materials that might
interfere with or bias the chemical analysis since the proportions
of mortar components are calculated from data obtained
by the chemical analysis methods.
Laura J Powers, Associate Principal and PetrographerSusanne Papas, Senior Associate and Chemist Wiss, Janney, Elstner AssociatesNorthbrook, IL 847.272.7400
ReferencesAnnual Book of ASTM Standards, Vol 4.05. West Conshohocken: ASTM International, 2010.
Beaubien House_Final_ME-SP Vol6_No1 7/15/11 12:58 PM Page 46
masonryedge.com Masonry’s Added Value 2011 Vol 6 No 2 MASONRY EDG E / the storypole 47
Repairs and DocumentationAfter mockups were evaluated and mortar
formula determined, repairs were made to
Beaubien House. The repair area was roughly
100 sf. The majority of the repair involved
repointing joints. Multiple brick were replaced
due to cracking. Another portion of the wall
contained obvious repointing with a mortar
mix that did not match the surroundings. Those
joints were raked and repointed with the new
mortar. Areas of repair were documented
photographically along with the method used,
brick supplied and formula for the mortar
mixture. A full architectural specification was
not written as the petrographic analysis report
was included in the documentation of the
process. This informa tion was compiled into
one document to be kept by the AIA.
As with any structure, Beaubien House must
be maintained and repaired. The brick
masonry structure continues to function and
look beautiful after more than 150 years of
use, while having had multiple owners and
uses. Brick is capable of lasting for thousands
of years with proper maintenance. There
is always the potential for a change of
occupants, so documentation of work is
important. In the future, a mason contractor
should not need to perform a petrographic
analysis or take mortar samples. Instead, they
can rely on the documentation to develop a
mockup and complete a repair. nnn
Meredith Steckling,AIA,CDT, LEED GreenAssociate, is an associatewith SmithGroup’sLearning and BuildingTechnology Studios. She is currently a Project Manager withextensive experience in the analysis anddevelopment of exterior
building envelopes including wall systems, roofing, windows and waterproofing.Steckling serves on the Board of theBuilding Enclosure Council – Greater DetroitChapter. She holds a Bachelor of Science inArchitecture from the University ofMichigan and a Master of Architecturefrom Lawrence Technological University.
Got building problems? We have your solutions.
SmithGroup Building Technology ServicesFor over 30 years, SmithGroup has o�ered comprehensive professional services including professional service evaluations; forensic investigations; traditional and specialized system and component design; construction quality management; HVAC and other system commissioning; maintenance evaluations; pre-purchase assessments; existing facility evaluations; mechanical, HVAC and electrical system analysis and design; peer review; and construction dispute support.
www.smithgroup.com
Beaubien House_Final_ME-SP Vol6_No1 7/15/11 12:58 PM Page 47