Project Type: Evaluation, Design, Bid Assistance and Construction Administration
Roof Replacement With Balcony & Exterior Wall Repairs
Issue
Vital Structures was retained to perform roof replacement engineering services for a pharmaceutical lab and office building. In addition to general age and deterioration, the facilities manager noted that after a RTU upgrade project, leaks had occurred into several mechanical penthouse areas below.
Diagnosis
The building consists of several complex roof areas and varying wall systems. One area of specific concern is the two (2) mechanical mezzanine roofs – congested with ductwork and equipment for the pharmaceutical laboratory and office space. Vital Structures performed an evaluation of the existing EPDM roof system; including review of original design documents, review of previous infrared roof scan documentation, exploratory test cuts, and limited peer review of the mechanical upgrade project. The following conditions were noted by Vital Structures:
- Mechanical duct supports mechanically fastened (screwed) through the roof membrane
- Saturated roof assemblies, leading to poor thermal insulation performance.
- Un-sealed roof penetrations
- Abandoned-in-place sleepers, blocking and mechanical/electrical penetrations.
- Roof membrane punctures and insufficient slope-to-drain due to saturating and crushing of the roof assembly.
- Slope-to-drain and concrete waterproofing termination deficiencies on overburdened balconies.
- Masonry through-wall flashing deficiencies.
- Failed gaskets at insulated metal panel walls.
Solution
Vital Structures prepared an evaluation report and developed complete building envelope repair design documents, including the following:
- Full roof replacement with R-30 roof assembly, improved slope-to-drain, and crickets at roof drainage obstructions.
- New through-wall flashings and masonry coating at rising walls.
- New sealant joints with pre-compressed foam backer to replace metal panel gasket system.
- Modification of HVAC duct supports
- Replacement of deteriorated wood blocking with insulated metal curb bases.
- New roof overflow drainage.
- New roof access doors with increased flashing heights.
