The waterproofing substrate must be properly prepared prior to the application of the plaza drain flashing material. Any openings and/or defects in the substrate must be properly repaired. An excellent source for designers is the inclusion of ASTM D-5295 as a standard for the identification and repair of any concrete defects. In addition to the substrate preparation, some manufacturers require that primer be applied over the drain bowl to aid in the adhesion of the waterproofing membrane.
Apply a layer of the waterproofing flashing material over the substrate in accordance with the manufacturer’s requirements. The flashing shall be fully adhered to the substrate and shall extend a minimum of three (3) inches into the prepared drain bowl. Apply a continuous bead of the manufacturer’s approved sealant at each termination point of the flashing material - in the bowl and over the substrate.
Apply the waterproofing membrane material a minimum of six (6) inches onto the waterproofing flashing material. Application shall be in compliance with the manufacturer’s installation and termination requirements.
Note: Prior to the waterproofing application the collar of the drain assembly should be adjusted to ensure that it is flush with the substrate.