The Museum of Science and Industry is housed in the former Palace of Fine Arts, the only building constructed for the 1893 World’s Fair Columbian Exposition that remains at the site. It is the largest science museum in the Western Hemisphere.
RRJ was retained to investigate the causes of water leakage through the museum’s main stairwell skylights. The investigation included a review of available skylight shop drawings, an on-site visit to document the locations of visible water stains and plaster distress below the skylight over the stairwell and on the interior surfaces of the skylight glass, and perform field water leakage testing of the southeast skylight.
The skylights are constructed over the four main stairwells and have a domed configuration supported on copper and limestone-clad concrete turrets atop square limestone-clad load-bearing masonry bases. Structural support for the skylight rafters is provided at the sill end by the turret and intermediate points by a preexisting riveted steel frame with 12 radially oriented curved ribs. The skylights are not directly visible from the building interior due to the presence of a nominally square diffuser panel system with 25 frosted panes. The diffusers are centered below the skylights above. Plaster perimeter moldings and curved crowns provide the transition from the stairwell walls to the diffuser opening.
RRJ’s investigative findings documented numerous sealant adhesion failures within the silicone wet glazing at the sill and intermediate horizontal framing members, water streaks and stains on the interior surfaces of the skylight IGUs, the turret curb copper flashing at the base of the skylight rafters and diffuser panels, and plaster damage in three clustered areas corresponding with the skylight rafter groupings.
RRJ provided recommendations of remedial approaches to address the identified water leakage paths within the southeast stairwell skylight. As the skylight construction over the other main stairwells is essentially the same and is likely to have the same deficiencies, these recommendations should apply to those areas as well.
