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portrait of Gary BlankenshipBy Division Manager Gary Blankenship, with contribution from Project Engineer Kristin Carson and Superintendent Butch Malone.

Although masonry will outlast all other building materials, mortar will fail with time. One of the primary roles of mortar is to act as a sacrifice in order to save the brick. The SSRG Masonry Division’s recent work at Indianapolis Union Station is a great example of our experience in working with failing mortar to preserve historic brick facades.

Explore another iconic historic facade preserved by SSRG.

Indianapolis Union Station opened in 1888. Indianapolis was the first city to conceive of a union station, a railway station served by two or more separate railway companies. The original station opened in 1853, and then a much larger station was constructed on the same site beginning in 1886. The project was exciting for the Masonry Division because, even on a building as old as it is, the bricks are generally still in good shape.

Mortar Selection Matters

We understand the care required in selecting the appropriate mortar for a given job. We made sure our crew was specifically trained in the Lime Putty Mortar best for the scope of Union Station. Lime putty is the right pick for a job like this due to the nature of the brick. Bricks are like sponges; they should naturally absorb and release moisture. If you put hard mortar into a building like this, it would seal the moisture in and ultimately weaken the brick.

Mortar, or masonry cement, is made of aggregate and a binder. There are five types and strengths meant to withstand specific psi. The structure of Union Station is best suited for Type O, which holds up to 350 psi. To compare, when masonry units are laid beneath grade, the project would call for Type S (up to 1,800 psi) and new masonry calls for Type N (750 psi).

Check out a recent new masonry project. 

Type O mortar is a lime putty. This lime putty is made of water and quicklime. SSRG brought in a specialist from Heritage Group in December 2019 to train newer team members with this particular lime putty, and to refresh the skills of longer-tenured members.

Additional Scope

The project scope at Union Station included:

  • 100% grind-out and re-point of the mortar joints on the clock tower, as well as 13 turrets around all elevations of the building
  • Brick replacements
  • Brownstone patching on the clock tower band

When repointing a historic structure, a key element is a balanced mortar mix. It is equally important to perform appropriate wall preparation, have the right curing conditions, and of course, impeccable workmanship. The crew on the Union Station job has thousands hours of experience in historic repointing.

Another SSRG project extensive re-pointing of black, rough-faced granite.

The project began with training in January of 2020. Scaffolding was erected in early March, and the project was substantially completed by the end of June. That’s 10,000 SF of façade repairs in less than six months. The bulk of the project occurred through the winter months, demanding that the the team to  with weather and temperatures, particularly when working with such specific materials.

Union Station is currently in use as office space, hotel, and a stunning event venue. In fact, it is the official location of the 2020 NFL scouting combine.

Want to join a team proven to deliver excellence? Check out our job opportunities and join a company that rises to the challenge and extends the life span of any structure. Join SSRG and be a part of Tough Jobs, Done Well.