CDCR will replace the roof of San Quentin State Prisons' above ground, poured in place concrete water tank. The roof consists of wooden joists/rafters, overlaid with redwood sheathing, overlaid with 3/4" marine grade plywood, densdeck, and a
PVC membrane. The redwood sheathing has severely deteriorated, rotting in place and pieces continually fall into the potable water; creating a public health hazard. The marine grade plywood has deteriorated to the extent that it is no longer safe to
walk on the roof. Additionally, the tie-downs between roof rafters and the supporting structural beams are missing which make the tank vulnerable during an earthquake. The institution is at risk of not having sufficient supply of drinking water and
sufficient capacity of firefighting should fire occur after an earthquake, as the water tank holds water for both purposes. The proposed roof design raises the roof of the water tank by 2' to 7' to satisfy the current California Building Code requirements
on sloshing for regions with moderate to high seismicity. This project will contribute to unimpeded operations at the facility.