Window and Building Envelope Assessment, Navy Hospital

Pensacola, Florida | 120,000 sf | $600k

PRIME conducted an envelope assessment on an existing eight story, occupied Naval Hospital constructed in the 1970ís. Original construction drawings were provided. The exterior wall construction was a minimally insulated cavity wall construction consisting of pre-cast concrete panels with masonry backup. The typical precast panels were smooth finish architectural style panels. Accent panels with exposed stone aggregate finish were used as trim, primarily at the upper wall to roof transition.

The study was focused on the exterior walls on floors four through eight including the edge of the roof. The facility staff noted a history of water intrusion at the hospital. Leaks were reported to be associated with the existing windows. The original windows were installed without sill flashings and relied on self-flashing windows and sealant joints at the perimeter. The partially operable aluminum window units were replaced in 2005 using similar techniques.

The investigation included a review of existing condition drawings, interviews with facility management staff and various facility occupants, and on-site observations including exterior visual inspections of windows and pre-cast panels as well as spray testing of the windows and walls. From samples collected of through-wall flashing, it was suspected that joints in the material were failing. Observations made during the assessment included: sealant joints associated with precast panels require replacement due to age and at the window perimeters as installed was ineffective.

Results indicated that window assemblies and precast panel joints and adjacent through-wall flashings were leaking. Roofing components were also assessed for potential impact on the wall leaks; a lack of appropriate wall insulation was noted; recommendations included replacement of perimeter flashings based upon observations. The complete assessment report was submitted along with recommendations for corrective actions with multiple options with related cost values. Proposed repairs included barrier system enhancement to minimize water infiltration into the wall cavity.