Wrigleyville in Chicago: Roof Investigation

PROBLEM

The main roof of this 6-story rectangular building is irregular in plan with multiple jogs at its perimeter. Water leakage from the roof has been a chronic problem since the completion of the conversion of the property to residential condominium use. The main roof perimeter terminates in two different conditions, gravel stop or masonry parapet wall. We were contacted to perform a visual inspection of the existing roof and provide repair options for the building.

SOLUTION

• Perform a noninvasive investigation of the existing roof of the building.

• Provide roof repair options for the building.

• Perform an extensive condition survey on the roof for the preparation of construction drawings, such as taking core samples at high and low points of the roof.

• Provide construction drawings for roof replacement.

• Install a new roof, per US-BES drawings.

VALUE

During the investigation, it was discovered that existing repairs to the roof membrane and associated seams were performed in an apparent attempt to address the active water leaks. The most common repair had been the installation of hot asphalt patches over existing seams or holes in the membrane. Over time the asphalt has become brittle and thus compromised the repairs. There are numerous areas that were soft when walked upon which indicated moisture penetration through the existing membrane that had become trapped. The existing roofing system consisted of multiple layers and at least two different roofing systems applied over the years, adding weight to the roof structure as well. The complete removal of the existing roofing system and replacement with a new system was implemented.