United States Courthouse and Federal Building | Milwaukee, WI
Courthouse History
The “Crown Jewel” of Milwaukee, the United States Courthouse and Federal Building was built in 1899 in the Richardsonian Romanesque style. Known for its monolithic granite exterior and 5-story glass atrium interior, this building housed multiple governmental institutions, including the U.S. Post Office and U.S Courts.
After 1968, when the U.S. Post Office relocated and the courts expanded, the southern corridors of the atrium were enclosed to make room for new offices.
Two decades later, the United States Courthouse and Federal Building earned its National Historic Landmark status, and thus began the ongoing extensive restoration that continues today.
To restore the open balconies in the atrium, the southern third floor offices are now demolished, revealing the damaged historic mosaic tile flooring that lines the corridors. Marion Restoration is currently repairing the tile floor to its original condition on the south run of the third floor corridor.
The Project
The United States Courthouse and Federal Building in Milwaukee has one inch by one inch hand-cut marble tile flooring throughout its corridors. Over a century old, this flooring has seen much foot traffic and repairs, some using inappropriate techniques that resulted in further damage. Marion Restoration was contracted to replace individual broken tiles and deteriorating grout, as well as to repair cracks and separated mortar bedding below the tiles.
Due to the irregularity of hand-cut tiles, extreme care must go into removing tiles that are cracked or chipped. Using a hand drill and chisel, each tile is cut from the floor with delicate precision as to not damage the surrounding tiles.
Larger cracks that span the width of the corridor hint that there are problems below the surface. Most often, these cracks are a result of structural shifts in a building putting stress on inflexible grout and mortar bedding. A lime mortar was originally used in the tile flooring. This is a softer, porous material that flexes with structural movements. It is evident that areas of the flooring were repaired using Portland cement as bedding mortar and grout instead. Portland cement is a modern material known for its compressive strength and lack of flexibility, thus cracking under stress.
To remedy these cracks, tiles are removed four deep on either side of the crack and those unbroken are kept for re-use. Then the first layer of bedding mortar is removed, exposing the top of the lower bedding mortar and the base of the crack. Heritage Injection Grout is then injected into the crack and its surroundings in order to infill all damaged areas.
A liquid bond breaker is applied to the top of the bedding mortar approximately three inches on each side of the crack to prevent any new movement from resulting in cracking. A custom blended bedding mortar is installed atop the bond breaker, followed by a half inch layer of dry-laid grout. This grout does not leaven like wet grout and will hold the irregular mosaic tiles in place without them settling at different levels. Finally, the mosaic tiles are reinstalled one-by-one like assembling a puzzle because of their unique shapes. Many of the original tiles are reused, some are stock from when the Federal Building was initially constructed, and any extras needed are cut by hand from matching marble.
These tiles are then pressed level and dampened to cure the dry-laid grout. A final layer of exposed aggregate grout is applied to the top of the tiles to match the historic appearance of the rest of the corridors.
The floors are then cleaned and polished, revealing seamless patch repairs and restoring the historic quality of the United States Courthouse and Federal Building.
US Heritage Products & Services
Services
Repointing Mortar
- Custom Grouting Mortar
Stone & Terra Cotta
- Custom Bedding Grout
- Heritage IG10 Injection Grout
Contact us with any questions. Also, visit our sister company Marion Restoration for additional information on historic restoration and preservation.