The drainage condition of a roof where all water is gone from the roof surface within forty-eight hours of precipitation during normal drying conditions.

the drainage condition in which consideration has been made for all loading deflections of the deck, and additional roof slope has been provided to ensure drainage of the roof area within 48 hours of rainfall.V Primer a thin, liquid bitumen applied to a surface to improve the adhesion of subsequent applications of bitumen.

when consideration is made to provide deflection of all water off the roof deck within 48 hours