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BACKGROUND The Pleasanton Library was constructed in 1988 with a concrete tile roofing system. After recent regular reports of water leaking into the building during rain events, Interactive Resources, Inc. (IR) was hired to complete an assessment of the building's waterproofing systems. The assessment determined the original underlayment of the tile roof was at the end of its useful life and noted water intrusion around the upper clerestory windows. The assessment also noted damage to several building components resulting from the water intrusion. On December 15, 2021, staff authorized a task authorization for $91,663 under an on- call agreement with Dahlin Group to provide design services to correct the issues identified by IR. The project was designed and bid as the Library Roof Replacement Project, CIP No. 14408, although the project includes more than the replacement of the roofing system. DISCUSSION The Library Roof Replacement Project base bid includes the removal and replacement of the entire 35,500 square feet of the tile roofing system. The project also includes the removal and replacement of the 2,800 square feet of single -ply membrane roofing material - which is in the flat areas of the roof and not visible from the ground. It is estimated that approximately 5,000 square feet of water -damaged wood sheathing will be replaced; however, this amount could increase if more damaged sheathing is discovered after the removal of the roofing system. The wood facias around the entire building perimeter will be replaced due to water damage and/or dry rot. The gutters and downspouts will also be replaced as they have been damaged over the years by debris and standing water. Gutter leaf protection will be added to reduce the need for cleaning. This leaf protection is expected to reduce the potential for similar damage to the gutters in the future. Additional gutters and downspouts will be added in locations of concentrated run-off to better control water flow. Roof anchors for a fall -protection system and walkable tiles will also be installed to allow safer and easier access by maintenance personnel. Finally, the middle clerestory windows, which provide natural light to the middle interior of the building, will be replaced. These windows will be reduced slightly in size to allow for proper flashing to minimize the potential for future water leaks. At the request of library staff, the clerestory windows will be tinted to reduce sun glare. The clerestory windows located on the east and west sides of the library are constructed similarly to the middle windows. However, since the assessment did not reveal any evidence that they were leaking or had leaked in the past, and due to budget concerns, the similar removal and replacement of the east and west windows was designed as an additive item. Due to the lower than the anticipated bid amount, and the understanding that replacing the windows as part of this project would prevent the potential for damage to the new roofing system if the windows do similarly fail and are replaced in the future, staff's recommendation also includes awarding the additive bid item 1 for the east and west clerestory windows. The existing roof -mounted HVAC equipment access locations are undersized and difficult to use. Access to the roof requires crawling through a portion of the attic and bringing a step ladder to reach up to the roof hatches. The newly designed system will improve safety by installing dropdown access ladders and allow for easier access to the Page 2 of 4