Connecting pvc to pvc with no hub fitting
My plumber ran into a dilemma when installing rough plumbing for a new basement bathroom. After already laying the pvc piping in place under the broken up concrete floor we found the pvc to cast iron Tee connections leaking. This was discovered after I had filled the opening with a base of gravel under the pipe and covered the pipe with sand. I noticed the leaking by the existence of wet sand... luckily prior to my pouring cement to finish. The plumber came back and found that the no hub bands he used were slightly off. He replaced them with appropriate size and the leak is fixed. In doing the band replacement he had to cut the 2" pvc drain pipe about 2ft before the tee connection, wiggle off the Tee connection from the cast iron and put on the new bands. When he reconnected the cut 2" pvc which leads back to the tub drain he used another no hub band to connect 2" pvc to 2" pvc. I wasn't home when this work was done, but my guess is that he used the band instead of a pvc connector because he couldn't fit it on without undoing my gravel/sand work. My question is: is the band OK for the pvc to pvc connection underground? Or should I dig up the pipe and have it relaid with all pvc to the Tee?
Also when I do the cement work, is there a reason to avoid having cement directly in contact with pvc pipe and/or bands?
Thanks
Jim