introduction Manhole Openings Rough Cut (“Scarred”) Openings Rough cut, or “scarred”, openings are made in a drycast manhole or box section before the piece is cured. Here, the concrete is chipped away around the desired opening to expose the reinforcement. Depending on the size of the opening, the reinforcement and concrete within the opening is left in place to be removed in the field. Rough openings are generally provided for larger opening that either cannot be cored, or are more cost effective versus cutting and coring, provided that production schedules allow. concrete pipe Cored Openings Cored openings are made in a finished product using specialized cutting and coring equipment. These openings can be provided either at the plant facility or in the field, but is generally conducted by a third party and has an associated added cost. Cored openings have the advantage of a smooth finish, and in some cases can accommodate a gasket such as the PSX: Direct Drive boot gasket. stormwater treatment technologies Gasketed Openings Gasketed openings are either provided by either casting the gasket directly into the opening, or by coring and installing a boot-style gasket. A gasket provides an engineered connection that reduces infiltration and exfiltration versus a standard mortar connection. Gaskets are not always available for all openings. The most common barrier to providing gasketed openings is the joint between manhole sections, which does not provide for the continuity required for a proper seal. box sections manhole and catch basin material LAFARGE PIPE eMANUAL PAGE 43