25-33 - Equalization and Retention Building Roof Repairs

The purpose of this Request for Proposal (RFP) is to select a construction firm to perform concrete repairs, roof drainage enhancements, waterproofing, and reroofing at the Equalization and Retention Building at the Water Resource Recovery Facility (WRRF). This work is necessary to prepare the roofs for future installation (as a separate project) of a photovoltaic array.

The project includes cleaning and surface preparation, concrete slab repairs, concrete wall/curb repairs, and crack routing & patching. Drainage enhancements include installing supplemental drains and retrofitting existing drains with new dome strainers. Waterproofing enhancements include removing and replacing expansion joints and installing a new protective coating over most of the roof area. Other miscellaneous repairs include concrete pad replacement, guardrail post base repairs, and demolishing and patching unused equipment bases.

The existing building was constructed in approximately 1979. The roof structure is conventionally reinforced cast-in-place concrete flat slabs supported on concrete columns. The top of the concrete roof surface has Thoroseal (or similar) present that is believed to have been installed during original construction. Existing expansion joint treatments appear to be Combiflex tape (or similar) adhered with epoxy. The elevated roof has an existing TPO membrane system, which will be replaced.

The facility is anticipated to remain in-service during the duration of the project, with the predominance of work occurring on the top of roofs; access to the tank inside the building is not anticipated.