The renovation of an 86-year-old historical building in Pittsburgh – the Energy Innovation Center (EIC) at the site of the former Connelly Trade School – took special care in preserving the building’s interior features. The building’s 20,000-square-foot concrete floor was poured in 1930, and the surface was severely spalled and cracked in many areas.
The restoration process included a cementitious overlay to repair the existing concrete, an epoxy primer and a two-component waterborne polyurethane topcoat based on high-performance resins and technology from Covestro LLC to protect long term against wear and stains.
The selected topcoat was a commercially available product, Sherwin Williams GP4409 WB polyurethane satin, that featured low volatile organic compound (VOC) content and vapor permeability in a water-based, aliphatic polyurethane clearcoat. The VOC content of the topcoat is less than 50 grams per liter of co-solvent, an important consideration for the building’s LEED Platinum certification aspirations. It provided similar performance characteristics and ease of application as a solvent-based polyurethane system, but with very low odor during application.
Choosing a topcoat with a long working time was crucial because the concrete was constructed with minimal day joints, saw cuts or other breaks in the surface. After allowing the floor to cure overnight, contractors were able to walk on the area to access other parts of the EIC.
According to Steven Reinstadtler, market manager, Construction Coatings, Coatings, Adhesives & Specialties, Covestro LLC, “Other important qualities include UV stability, durability, longevity and good chemical and abrasion resistance. The high-performance coating will protect the floors from foot traffic, wheeled carts, stains and abrasion for years to come.”
The end result was a fully restored, continuous walkway that blended into the updated neo-industrial look. The floor finish imparts a homogenous look into a large space and keeps the area looking clean. The lower sheen satin finish contributed to the desired aesthetics and minimizes glare from the overhead skylights.
Covestro offers a range of polyurethane raw materials for the production of high-performance, high-quality waterborne polyurethane coatings. Waterborne polyurethane coatings meet the increasing demand for environmentally friendly products with their ultralow VOC content. They also offer a unique combination of properties ranging from high efficiency during application to excellent film appearance, scratch resistance, and high resistance to water, solvents, chemicals and weathering.