An assembly and method of joining a pipe with a catch basin, the catch basin having an apertured side wall, the assembly and method including providing an elastomeric ring having an annular hollow expansion space, a foam injection port, a flow checking inflation valve for resesting fluid back flow within the foam injection port, and having a slide stop extending outwardly from the elastomeric ring; inserting the elastomeric ring into the catch basin's aperture; inserting an end of the pipe through the elastomeric ring; and injecting a closed cell resilient foam through the fluid injection port for expansion within the expansion space, the expansion driving the ring's annular inner and outer surfaces inwardly and outwardly, forming a seal spanning between the pipe and the catch basin.