DPWH Blue Book Volume 3 (2019 Edition) , formally titled the Standard Specifications for Public Works Structures
Division V - Electrical and Mechanical: Covers electrical wiring, power systems, and specialized mechanical installations for buildings.
Roofing and Waterproofing: Requirements for prepainted metal sheets, clay tiles, and specialized waterproofing systems. Division III-VI: Specialized Infrastructure
However, until the new edition is formally released and published in the Official Gazette, the 2019 edition remains the law of the land for Philippine public works.