I could really use your help with a question;

We recently had a new re-model tub installed.(Veritek BA-3060) Our contractor did not install this in mortar per the manufacturers instructions thus voiding the warranty. Plus it leeks through one of the walls because it is installed crooked.

He now wants to come out and make things right, but keeps warning us that he does not like mortar and we are going to hear creaking and cracking if he installs this way. Setting us up for this ahead of time. Of course the manufactures says " if the mortar is installed correctly you won't hear any cracking".
The contractor explains with the expanding and contracting of the tub with hot or cold water is what caused the space, and the creaking, which seems to make some sense.

Is this correct? Or could you explain the correct way to install the tub in mortar so I can make sure he does this correctly?

Thanks in advance
Mark
Rockfall, CT

Instead of mortar tryt modified thinset or USG STRUCTO-LITE Basecoat Plaster by USG Corporation Remind your contrator that he must install per manufacturers instructions or you will hold back money. Do not pay any contractor in full until the job is done and tested