Roofing a ziggurat

Renaissance Roofing restores an Indiana war memorial


  • A ziggurat is a pyramidal structure built in
successive stages with outside staircases
and a shrine at the top. The ziggurat roof on
the 210-foot-tall Indiana War Memorial has
16 steps.
  • On the ziggurat roof, workers
removed the existing lead sheet
roof system down to limestone
risers, replaced risers as needed
and then applied primer and
underlayment.
  • On the ziggurat roof, workers
removed the existing lead sheet
roof system down to limestone
risers, replaced risers as needed
and then applied primer and
underlayment.
  • On the ziggurat roof, workers
removed the existing lead sheet
roof system down to limestone
risers, replaced risers as needed
and then applied primer and
underlayment.
  • On the ziggurat roof, workers
removed the existing lead sheet
roof system down to limestone
risers, replaced risers as needed
and then applied primer and
underlayment.
  • An aerial view of the Indiana War Memorial’s
newly completed ziggurat roof system.

The roof systems under construction.
  • An aerial view of the Indiana War Memorial’s
newly completed ziggurat roof system.
The roof systems under construction.
  • Above photo: an aerial view of the Indiana War Memorial’s
newly completed ziggurat roof system
Photos on left: the roof systems under construction
  • Above photo: an aerial view of the Indiana War Memorial’s
newly completed ziggurat roof system
Photos on left: the roof systems under construction
  • Above photo: an aerial view of the Indiana War Memorial’s
newly completed ziggurat roof system
Photos on left: the roof systems under construction

THE INDIANA War Memorial Plaza Historic District in downtown Indianapolis is composed of Neoclassical buildings and structures, including the Indiana War Memorial. Like Greek architecture of the fifth century, the Indiana War Memorial is a square structure with columns and a pyramidal dome.

Constructed between 1926 and 1965, the Indiana War Memorial occupies one city block and has a mausoleum atop a plaza deck and auditorium. The face of the memorial is made of Indiana limestone. Each side of the tower has five large windows in between six stone columns above which stand six figures sculptured in stone to represent courage, memory, peace, victory, liberty and patriotism.

Water infiltration from the roof into the memorial’s interior and mausoleum was an ongoing issue. As a result, many historical plaster finishes and murals were damaged. The state of Indiana retained Wiss, Janney, Elstner Associates Inc., Chicago, to assess the roof areas and develop repair and replacement recommendations.

Renaissance Roofing Inc., Belvidere, Ill., was selected by the project’s general contractor, Structural Preservation Systems LLC, Schiller Park, Ill., to complete the roofing work.

Rehabilitating the Roof System

In July 2018, the Renaissance Roofing team began work on the Indiana War Memorial. The work was performed in three stages.

Ziggurat roof

A ziggurat is a pyramidal structure built in successive stages with outside staircases and a shrine at the top. The ziggurat roof on the 210-foot-tall Indiana War Memorial has 16 steps with rises ranging from 46 inches at the bottom to 21 inches at the top. On each elevation, the length of each step decreases from about 84 feet at the bottom to about 12 feet at the top. The depths of the steps on each level also vary.

To access the roof, workers constructed scaffolding on all sides of the building, and materials were loaded using a cable hoist. Crew members wore harnesses attached to ropes for fall protection while removing the existing lead sheet roof system down to limestone risers and replacing risers as needed.

To ensure proper adhesion to the masonry substrate, workers applied Perm-A-Barrier® WB Primer and then placed GRACE ULTRA™ high-temperature self-adhering underlayment. In the company’s off-site sheet-metal facility, Renaissance Roofing craftsmen fabricated 20-ounce lead-coated flat-seam copper roof panels and flashings and then fully soldered them on-site using single-lock seams over the sloped horizontal portions of the steps.

To attach the lead-coated copper to the masonry, workers used special fasteners. Stainless-steel screws were used to fasten the cleats and attach the roof panels and flashings. The lengths of many of the steps exceeded the recommended safe distance to fully solder a flat-lock roof system, so the team used expansion joints to divide the longer steps, allowing for expansion and contraction.

A hot work permit was required for all soldering operations, and workers strategically placed fire extinguishers for emergency use.

Perimeter gutter

For the perimeter gutter area at the base of the ziggurat roof, crew members removed the existing built-up roofing down to the masonry substrate. Then, they installed a wood nailer at the edge of the roof using stainless-steel concrete screws. Next, they attached polyisocyanurate insulation and DensDeck® Prime Roof Boards followed by Flintlastic® SA self-adhering SBS polymer-modified bitumen membrane.

In addition, workers installed a new flashing system, counterflashing, termination bar, sealants and fascia metal integrated with existing drains.

Statuary and colonnade levels

The statuary and colonnade levels each consisted of four elevations.

On the statuary areas, workers removed the existing polymer-modified bitumen and built-up roofing down to the masonry substrate. Then, they applied Flintlastic SA self-adhering SBS polymer-modified bitumen membrane along with new flashing, counterflashing, termination bar and sealants.

At the colonnade levels, workers removed the existing lead-coated copper roof system down to the masonry substrate and fastened 1/2-inch-thick DensDeck Prime Roof Boards followed by adhering GenFlex AFR EPDM membrane.

Challenges

Working on the Indiana War Memorial presented several challenges for the Renaissance Roofing crew.

“Restoring a historical landmark while complying with current building codes was a major design challenge and required careful review of the codes and discussions with the Structural Preservation Systems team and owner,” says Robert Raleigh III, president of Renaissance Roofing.

And installing modern roofing materials on a limestone structure is not a typical roof system procedure.

“Most manufacturers do not have testing data related to pull-off or performance with limestone,” says Peter Haupt, PE, senior project manager for Structural Preservation Systems. “Renaissance Roofing met the challenge by performing its own testing on-site and collaborating with roofing manufacturers to update standard roofing details to meet the unique site conditions and achieve client warranty requirements.”

In addition, sequencing of work could not be determined until masonry work was completed.

“Determining the order of our work depended on the masonry schedule because we were uncertain how many limestone blocks would require replacement and what size block would be needed,” Haupt explains. “It was Renaissance Roofing’s responsibility to always keep the building dry while awaiting completion of the masonry work.”

Weather was another issue for the crew as on-site work was completed during two summers when temperatures often were above 90 F with 30-mph winds at the top of the ziggurat. The winds made soldering difficult at times, and materials had to be secured to the scaffolding to prevent them from blowing off the roof. Team members started and ended work early on hot days and moved to a shady side of the building to take breaks from the heat.

A Memorial Restored

The Renaissance Roofing team completed work on the Indiana War Memorial in December 2019. Work took longer than anticipated because of changes required after workers discovered unknown building conditions during construction. And as an early winter season arrived in Indianapolis in October 2018, masonry and roofing work had to be paused.

But thanks to a dedicated team at Renaissance Roofing that treated the project with the attention and execution it deserved, the historical memorial was successfully restored.

“The Indiana War Memorial’s ziggurat is an extremely unique structure that required extensive planning and customizations to ensure the permanent roof system will protect the building for many decades,” Raleigh says. “Being responsible for fabricating and installing a roof system to protect a national monument dedicated to honor war heroes who served and protected our great nation truly was an honor.”


CHRYSTINE ELLE HANUS is Professional Roofing’s associate editor and an NRCA director of communications.





Sidebar:

Project name: Indiana War Memorial

Project location: Indianapolis

Project duration: April 2018-December 2019

Roof system type: Copper and EPDM

Roofing contractor: Renaissance Roofing Inc., Belvidere, Ill.

Roofing manufacturers: CertainTeed LLC, Malvern, Pa.; Firestone Building Products Co. LLC, Nashville, Tenn.; GAF, Parsippany, N.J.; GCP Applied Technologies Inc., Cambridge, Mass.; GenFlex,® Nashville

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