THE CHALLENGE
As part of a House Doctor contract with Barnstable Public Schools, CBI was engaged to review the exterior wall conditions at the Barnstable High School cafeteria addition, built in 1974. The EIFS wall had been taking on water and damaging both interior and exterior finishes, and there was evidence of water infiltration from excessive staining and lichen growth. The exterior insulation at the soffit above the rear exit door had become detached from the framing and prevented the exit door from opening, creating an unsafe condition that the local officials deemed an ‘emergency’. They shut down the exit and appropriated emergency funds so that CBI could investigate the conditions and propose repairs.
CBI’S SOLUTION
CBI investigated the underlying issues by removing four (4) sections of the wall (inside and outside) and observed the conditions and extent of the deterioration behind the finishes. The test cuts revealed that there was no sill flashing under the ribbon windows at the top of the wall, the entire exterior wall composition below the windows (consisting of the EIFS finish, 1” thick insulation, and 1/2” thick plywood sheathing) were all wet, and the cold formed studs were completely corroded. In addition, the batt insulation that once filled the exterior wall was saturated and had fallen to the bottom of the wall cavity.
CBI recommended replacing the entire wall system because all the components were deteriorated beyond repair and their ability to resist or transfer loads of any kind were severely compromised. Furthermore, they jeopardized the ability of the wall to keep water away from the building’s structural elements and from infiltrating the interior spaces. CBI also recommended removing the ribbon windows and infilling them (they had already been blocked by a hung ceiling inside and no longer provided natural light), and they were also the main source of the water infiltration.
CBI designed a back-ventilated, high pressure laminate / phenolic resin panel rainscreen, complete with sub-girt profiles and attachments to transfer lateral loads back to the wall at the east and west elevations. The rainscreen was the first of its kind in the United States using a custom image processing in the laminate design. The end result was a sports motif (because the East wall faced the playfields) with silhouettes of male and female athletes that the School Department, students and parents are all proud of. CBI closely reviewed the shop drawings and final engineering details, and met with members of the fabricator (from Austria) in order to ensure that the panels were fabricated as intended.
