Installing ceramic tile in a 2000 Itaska horizon

Used flexibile grout in an application where I knew there would be some flex and fibration. Held up fine, 3 years going stong. It's more expensive but in the small space like a MH easily affordable. You can buy it in pre mix tubs at HD or Lowes. it's basically a layer of glue-like urethane liquid that you blend with the grout. It's a little tougher to work with and you have to be more vigilent with your cleanup but works well. Snapstone comes to mind. Laticrete 333 ad-amix can also be added to your thinset. It's used in place of water for your thinset mix and makes it flexible.