I'm trying to install 18' x 18' tiles on a concrete foundation ( in the basement of my 50 year old home. After removing most of the paint the former owner had applied, I laid down the tiles to decide on a pattern. It was at that point that I realized much of the floor (especially along the perimeter and at the threshold) was unlevel. Can the 'Thinset' compensate for this or do I need to 'level' this project and start over-
HELP! MY INLAWS ARE COMING!!