Commercial Architecture September 2017 - 18

FEATURE

exterior restoration
ble, was supplied by Bonstone Materials Corp., Mukwonago, WI.
The products included Bonstone Clear Gel Epoxy and Last Patch
Dymond. "We also provided a color-matched UV-stable-non-yellowing-patching system for the Dutchman joints and for chipped
corners when needed," stated Paul Klees of Bonstone.
QUARRYING AND FABRICATION

Once the first phase launched in 2013, Lackovic and her team worked
closely with Polycor to select blocks for the project that matched the
desired physical properties. "Blocks were hand selected, ranked, and
set aside for specific features," said the architect. "Existing stone is
highly variegated in color, and veining patterns have random orientation, for the most part. We did not have the luxury to match color
and veining for every piece of stone due to cost and schedule implications. The compromise was to select blocks with midrange color
and tone as a standard and then fleury-cut the blocks to help blend
new work with existing. Where veining pattern was more intentional,
we photographed the piece and requested that Dutchman be cut to
match where possible."
Although Polycor chose to control the fabrication, the responsibility of vetting the cooperating companies ultimately rested on Twin
City Tile and Marble Co., according to Joe Becker, vice president of
Above. Stone that was good enough to
keep received minor repairs. Cracks were
filled, minor chips were occasionally
patched, and rough, granulated surfaces
were smoothed to facilitate water runoff.
Photo courtesy of Twin City Tile & Marble

the company's stone division. "Relationships were strengthened and
expectations realized during the many visits to the fabricator facilities," he stated.
According to Becker, individual stones selected by the architect
were measured and hand drawn while on the scaffold or swing stage,
and TCTM's field engineer coordinated the offsite creation of digital
shop tickets and full-sized templates. "After roughly 200 tickets were

Right. During the restoration of the
Minnesota State Capitol Building, master
carvers were onsite to produce full-sized
models when two or more matching
elements were required. Photo courtesy
of Mark 1

created, they were sent for approval," explained Becker. "Approval of
the shop tickets resulted in the start of fabrication. This sequence of
processing shop tickets was repeated until the phase was complete.
Measuring took place through each season of Minnesota. There was
not a stoppage during the winter months. A constant challenge our
team faced was to make no assumptions in measuring, as there was
no consistency of sizes in the same elements."
Becker stressed the importance of this process. "I think the vital

COMMERCI A L A RCHI T EC T URE

said Lackovic. "As part of the planning process, extensive full-scale

and crucial success of this project was the shop tickets," he said. "It

mock-up trials were designed to test the various repair strategies un-

doesn't sound that interesting, but they resulted in less than a 1%

der consideration. To insure that repair strategies were critically re-

error rate. It was the heartbeat of the whole job. We were all working

viewed across a wide spectrum of influences, trials were performed in

off the same thing. After the fabricators were through with the shop

three locations. This allowed us to review results at various times of

tickets, they went to Mark 1 Restoration. Because of the pace of the

the day, in different ambient conditions. It also allowed investigators

deadline, Mark 1 had to do demo before the stone arrived, so they

to evaluate whether exposure to differential climate factors influ-

relied on the shop tickets. To me, they are one of my biggest accom-

enced the natural weathering process. The trials provided an invalu-

plishments."

able opportunity to explore options, demonstrate installation proce-

Monica Gawet, president of Tennessee Marble Co., was proud to

dures, test process, inform schedule, generate unit accurate prices

be part of the restoration project. "Tennessee Marble has been a fab-

based on actual time and materials, and judge overall aesthetic im-

ricating partner with Georgia Marble since 2000," she said. "As a

pact ahead of time."

domestic and historic company that does restoration/renovation and

While a significant number of stone pieces needed to be replaced

historic material, we enjoy collaborating with other domestic part-

on the exterior facade of the building, the objective of the restoration

ners. We were also excited because J.E. Dunn is a wonderful contract-

was to preserve as much of the original stonework as possible. "Stone

ing company, and they chose TCTM. We have known Joe Becker for

that was good enough to keep received minor repairs-cracks were

the past 10 to 12 years. I even knew Sylvie at Polycor. We had done a

filled, minor chips were occasionally patched, and rough, granulated

Georgia white job together. She's a shining star-very committed and

surfaces were smoothed to facilitate water runoff," explained Lackov-

organized.

ic. The color-matched epoxy for the bonding and anchoring during

"This was certainly unique," she said. "It was not just fabrication.

the Dutchman installation, as well as any reattaching of broken mar-

It was carving and shaping. It was extremely high profile. We were

SEPTEMBER 2017

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