A masterpiece of Art Deco architecture, Buffalo, New York’s City Hall is a soaring structure that has overseen the waters of Lake Erie since 1929. Standing 32 stories high, the building is constructed of carved sandstone and terra cotta, and is comprised of a domed central tower, flanked by two side wings. The building is designated a historic structure by the U.S. Department of Interior.
After nearly 80 years of exposure to severe freeze and thaw cycles, the building required significant cleaning, as well as repair, stabilization or replacement of damaged stones. In addition, masonry joints needed to be repointed, Dutchman was in need of replacement, and parapets demanded reconstruction. The structure also needed to have sealant replaced on windows and doors, as well as complete restoration of the bronze windows on the first four floors of the building.
The project involves:
- Scaffolding up to the 15th floor of the building’s left wing
- Roof replacement on the 15th floor
- Reconstruction of parapets on 14th floor
- Cleaning and restoration of the left wing façade
- Epoxy injection into cracked stones
- Repointing of masonry joints
- Sealant replacement around windows and doors
- Repair or replacement of damaged stonework
- Stone carving to replicate the appearance of the existing sandstone blocks in the façade
- Cleaning and restoration of the main entrance area above the mezzanine up to the 15th floor
- Restoration of the building’s corners, where significant stone deterioration had occurred
- Restoration of bronze windows on the first four floors of the building
Project Details
Name: Buffalo City Hall
Completion Date: 8/1/2009
Owner: City of Buffalo, New York
Architect: DiDonato Associates
General Contractor: Graciano Corporation
Project Included
- Unit Stone Replacement
- Structural Steel Repair/Replacement
- Stonework
- Stone Patching
- Sealants
- Repointing Masonry
- Parapet & Coping Reconstruction
- Paint Removal
- Masonry Surface Rehabilitation
- Masonry Cleaning
- Lintel Replacement
- Flashings
- Dutchman Repair
- Chemical Cleaning
- Brickwork
- Alkaline Cleaners
- Acidic Cleaners
Glossary Terms
WaterproofingIt’s important to waterproof concrete structures to keep moisture out of the facility and to protect the structural components of concrete and imbedded reinforcing steel. If the integrity of the concrete is maintained, it can remain waterproof. Polyurethane is considered one of the best waterproofing materials. It can be applied seamlessly and penetrates the surface deeply and evenly. The polyurethane membrane will fill in even the finest cracks in concrete, reducing its water absorbency capacity. Many types of waterproofing systems can be used depending on your home’s structure
Urethane Foam or Epoxy InjectionUrethane Foam or epoxy injection is a cost-effective and permanent way to stabilize and seal cracked or compromised masonry surfaces. Depending on the size of the crack, urethane foam or epoxy is injected into the void and allowed to cure. Once hardened, these materials help form a stable subsurface to support masonry restoration operations.
Tuck PointingTuck pointing entails removing loose or cracked mortar from brickwork or stone installations and replacing its new mortar to ensure structural integrity and to seal out damaging water and moisture. Mortar for tuck pointing must be carefully selected to ensure that its color and texture of the new mortar closely matches the existing material that was not compromised and did not need to be removed.
Terra Cotta Replacement and RepairTerra cotta is a building material that is cast from clay and then glazed. Terra cotta components add great color and detail to a building, but are also highly susceptible to cracking and damage from impacts or freeze and thaw cycles. In many cases, damaged terra cotta sections must be removed and replaced with new materials to prevent water infiltration and structural damage. Replacement components must be created to replicate the design of the original piece, as well as the coloration that is acquired as the surrounding pieces age. Frequently, it is necessary to repair and stabilize the structural underpinnings that support a terra cotta installation, as corroded pins or structural supports can cause further damage as time passes. In cases where a terra cotta component has sustained minor damage, it is often possible to perform repairs on the piece without removing the compromised element from its installation.
Masonry RestorationMasonry restoration involves the repair of existing masonry materials or the complete replacement of damaged materials with new or reclaimed bricks or stones. Color and texture matching are key considerations in masonry restoration, as an accurate match can make areas of restored stone or brick blend in seamlessly with existing materials. To achieve an accurate color and texture match, it is frequently necessary to return to the original brick manufacturer for replacements, or to the original stone quarry where material for the existing stone components was cut.
Masonry CleaningMasonry cleaning entails the removal of dirt, debris, paint, and graffiti from various surfaces of masonry structures. Commonly used masonry cleaning techniques include high and low – pressure washing and chemical cleaning. Regardless of the method used, special care is taken to avoid over cleaning – and possibly damaging – aging masonry surfaces.
GroutingGrouting is used to seal the spaces between masonry installations such as tile or terra cotta. Grout may be colored to blend with the masonry materials, or can be used to create contrast within the masonry design. Grout is typically applied by hand by filling the joints with material and then troweling it out over the adjoining tile or terra cotta. Once the grout has set, a craftsman returns to the area that was grouted and removes any excess material from the face of the installation. As grout is frequently porous, it must be sealed once it is completely dry to protect it from dirt infiltration.
EIFS CleaningExterior Insulation and Finish Systems cleaning, also known as EIFS cleaning, involves removing dirt and grime from the exterior surfaces of structures clad in Dryvit or other types of stucco–like materials. To avoid damaging the thin exterior skin of these structures, mild cleaning agents and low–pressure water is most frequently used to dislodge surface dirt. Manual cleaning is also used to remove dirt in hard–to–reach areas or intricate detail.
CaulkingCaulking is used to seal gaps between masonry surfaces, such as brick or stone, and other architectural elements, including window and door frames, decorative hardware or lighting fixtures. Caulking is most often applied with a gun, and is available in butyl, latex or customized formulations. The color of caulk is selected to match the surfaces surrounding the application site. When applied, the caulking gun is inserted in the gap to be filled. Caulking material is then injected into the void to seal the opening.
Abrasive CleaningHeavily soiled masonry surfaces may require abrasive cleaning to effectively remove deposits of grime, paint or graffiti. Abrasive cleaning typically involves high–pressure application of sand or another type of inert, abrasive material directly to the masonry surface. When the abrasive cleaning has been completed, the masonry surface is frequently rinsed with low-pressure water to remove any remaining dirt or cleaning materials.