6. If the specifying engineer requires a woven, unwoven or poly fabric wrap, it should be applied at this time. If used, the wrap should extend over casting flange and a minimum of 4” below top edge of concrete structure. If oversize manhole with top slab, wrap should rest a minimum of 6” out from rings and on top of slab.
*If a concrete collar is poured around catch basin ring and casting, fabric is not required.