Hello, Looking to split a bedroom into a en suit and main bathroom.Im going to erect the stud wall myself and get a plumber to fit shower tray etc. The area where the tray is to be is 1140mm wide. Looking to get a 1100 tray leaving 30mm gap. Would you move the stud in by 30mm as I was wondering about the overlap on the shower tray, and also preventing having to cut small tiles?