Applications of flashing at cast-in-place penetrations (such as pipes or vents) are similar for both vertical and horizontal waterproofing applications. As with all adhered applications, it is critical that the surface to waterproof is properly prepared. The surface (metal) shall be free of all oils and contaminants. It may be necessary to sand the surface prior to the application of the manufacturers approved primer.
Most manufacturers require that their membrane be applied over the surface prior to the flashing application. The flashing material must be a reinforced material - even if the membrane is non-reinforced. Once the membrane is properly adhered, apply the reinforced flashing material in accordance with the manufacturer’s requirements. .
Apply a collar at the top of the flashing material for securement.