Project Owner: U.S. General Services Administration (GSA)
Mills & Schnoering Architects
Wiss, Janney, Elstner Associates
The Tradesmen Group
Location: Milwaukee, WI
Pedestrian Canopy, System Scaffold Stair Towers, System Scaffolding
Drafting & Design, Engineering, PE Stamp
Scaffold Engineering: Universal Manufacturing, DH Charles Engineering
Shoring Engineering: GZA Geoenvironmental
Original construction of what is now referred to as North Building between 1892-99, addition of South Building floors 1-5 between 1929-32, later addition of floors 6 and 7 in 1940, added to National Register of Historic Places in 1973
Efforts to clean granite façade in mid-1960’s using acid wash ended up having opposite of intended effect, not good for health and longevity of the stone, accelerated weathering and deterioration
Sections of granite façade start to break loose in 2010-11, precipitated need for stabilization plan, added temporary netting to protect pedestrians, began 6-year process to gain approval for funding, $20+ million-dollar restoration authorized in 2016, restoration intended to last minimum 50-years
Comprehensive pre-construction design survey in 2017, stone by stone inspection via repel lines and boom lifts, evaluate condition of the stone and mortar joints, discover major issues with eroding metal and cracking granite
Work begins in 2018, has to be split into two work seasons due to harsh Wisconsin winter, cleaning efforts more effective in warmer conditions, condensed work schedule required high-level planning and coordination from the entire project team
The Tradesmen Group
Highly-skilled team of artisans and craftsmen who take exceptional pride in the preservation, rehabilitation and restoration of significant structures throughout the United States
Universal has played a key supporting role in The Tradesmen Group’s operations across a wide scope of projects. From quality equipment and custom fabricated components, to engineering services and scaffold safety training, our strength is your support.
The building’s most iconic feature also presented some of the most significant challenges for our engineering team, almost 200-foot height requirement, 26 total working levels, 12 working levels above roof elevation of main building, 360-degree access to tower façade
In order to achieve the height requirement, we needed to reshore North Porch and its supporting structure, engineer a beam structure to rest on top of porch roof to support erection of universal system scaffolding up the façade of north inset elevation
TTG required 360-degree access above severely sloped roof, team engineered beam structure spanning the main tower roof more than 90-feet in the air, surrounding the feature on three sides. This framework allowed hanging of additional working levels below the beam to access otherwise impossible to work on sections tower façade, each platform tapering in size to match roof angle of decent
Wind-loads produced by working enclosures required high-level engineering calculations and load analysis to ensure safe working conditions, PE stamped prints indicate restricted areas and maximum levels of sound curtain that can be installed at any given time
The building remained operational throughout the restoration process, UMC designed and engineered pedestrian canopy scaffolding rated in excess of 150psf to serve as overhead protection for the general public using the north porch among building entrances and exits
North Building Turret Repair
The edge and stone deterioration found on the turrets of the North Building was primarily the result of rusty anchors and the more than 100-year old iron bolts securing the gutter being drilled directly into the granite itself.
First TTG had to repair and repoint the granite using the dutchman process, then reframe the gutter structure using a non-deteriorating composite that could be easily fitted to the radius of the turret.
A talented team of metal fabricators recreated the profile of the original led-coated copper gutter, delivered those components to the site, and installed a new copper cladding on the composite framing before reattaching the gutters with stainless steel fittings that will not corrode over time.
At approximately 80-feet above street level, this work intensive aspect of the project was accomplished from a safe and stable platform constructed using Universal system scaffolding and an integrated material hoist.
Facade Detail & Retooling
Retooling is a process, especially in areas which are highly visible, where The Tradesmen Group will physically chisel and retouch the details of the stone by hand. It’s a step further than the micro-abrasive treatment, working to restore the stone it its original appearance and texture.
This treatment is particularly labor intensive treatment and requires close, immediate access to be accomplished effectively. The working platforms designed and engineered using Universal system scaffolding provided The Tradesmen Group the stability they need to accomplish their objectives.