Yes, all wall to tray connections must be waterproofed with KERDI-BAND. All KERDI drains need to be sealed to the tray using a KERDI collar, which is supplied with the tray. The KST183 shower tray (183 cm x 183 cm, 72” x 72”) needs additional KERDI-BAND to seal the two piece tray together at the dovetail connection.