The ground floor of the Salesforce Transit Center, San Francisco’s new central public transportation hub, has a light-filled, vibrant and inviting atmosphere thanks to light columns – a structurally expressive skylight and walkable glass floor combination that brings sunshine into the building. The largest of these columns located in the Grand Hall, the transit center’s primary public space, provides a light source all the way to the train platforms two stories below.

Architects Pelli Clarke Pelli specified the most demanding requirements for a fire-rated glass floor and skylight to date for this project including 2-hour fire rating, blast, and seismic resistance, live loading for foot traffic, and waterproofing.

Vetrotech and Greenlite Glass Systems Inc. produced and rigorously tested an innovative solution involving horizontal fire-rated glass, structural glass, and spacers with airgaps to avoid replacing glass due to dirt and condensation issues that would develop with foot traffic and the outdoor environment.

CONTRAFLAM LITEFLAM-XT-120 system – a walkable fire-rated glass floor and skylight was created specifically for the transit center. As the only exterior multi-panel system to pass all of the tests and comply with the specifications, CONTRAFLAM LITEFLAM-XT-120 allows the light columns to flood the Grand Hall with natural light.

PROJECT KEY ACHIEVEMENTS

•    The only fire-rated seismic-resistant product on the market
•    The first 2-hour exterior fire-rated seismic- resistant, blast-resistant flooring in the USA
•    Only glass fire-rated glass floor with sacrificial sheets

PROJECT KEY CHALLENGES

•    10 years warranty
•    Fire testing
•    Durability and weather testing

STAKEHOLDERS

•    System Partner: Greenlite Glass
•    Building Owner: Trans Bay