(St. Louis, MO, Dec. 31, 2019) Modern commercial parking garages aren’t the only ones that require maintenance and repair; sometimes residential garages call for Western Specialty Contractor’s restoration expertise as well.
The Western Specialty Contractors – Minneapolis, MN Branch was recently contracted to repair the concrete slabs in a historic mansion’s two-car garage near Lowry Park in Minnesota. The garage, first constructed in 1931, consisted of two levels, one elevated at grade and one below grade. The original scope of work included a complete replacement of the 2”-3” topping slab (630 SF) and a localized full-depth repair of the 10”-12” structural slab (40 SF).
Working on a residential garage can be painstaking for all involved. Due to the noise and obstruction, keeping an open line of communication with the owner, contractor and design professional is paramount.”
After further investigation into the integrity of the structural slab, the quantity of the structural slab replacement increased to 280 SF, with additional work recommended for a drain replacement, overhead concrete patching, urethane grout injection, and application of sealants and a traffic coating.
“During the construction phase of the project, shortly after being on site, we discovered that the integrity of the structural slab was more compromised than we had previously thought, regardless of the core samples that were collected,” said Western Project Manager David Grandbois. “The rebar in the slab had corroded away to nothing and the slab turned to dust as we hammered. The parking slab provided horizontal support to the foundation walls, so we could not continue to remove massive sections without supplemental support.”
Full-height shoring from floor to ceiling was installed to provide a working platform, and side bracing was installed to prevent the walls from collapsing inward. The slab replacement and pour back had to be sequenced in two phases so that the entire slab was not removed at one time. A new, heavier duty rebar design was also required.
Since the home’s boiler system sat below the main level parking slab, Western’s workers took extreme care to protect the boiler during all phases of the project from start to finish.
“Hammering into nearly 100-year-old concrete can vary from its strength, rebar size and placement, and aggregates present. It is important to take your time while performing the investigation, discovery and demolition on this type of project,” said Grandbois. “Working on a residential garage can be painstaking for all involved. Due to the noise and obstruction, keeping an open line of communication with the owner, contractor and design professional is paramount.”
Western started the concrete repairs in January 2019 and continued to work on the garage restoration throughout the rest of the year. Western crews returned in November 2019 to complete the sealant and traffic coating part of the project to protect the restored garage. The engineer on the project was Meyer Borgman Johnson and the architect was James Dayton Design, LTD., both of Minneapolis.