I am laying a tile floor in my bath. When I pulled the carpet up I found one of the sheets of 5/8″ sub-floor had delaminated. I cut out the 65″x 21″ area, went to my supply house and found that all anyone now carries is 19/32 thick ply. My question is, will the latex-portland mastic between the sub-floor and the backer board make up the 1/32 nd difference or do I need to cut some shims and glue them to the joists??