Easy
It isnt necessarily the table man's fault. I service a pool room in a concrete structure, and the humidity is super high. When I install simonis there, I stretch it tight enough the slate buckles!!(not literally) However, after time goes by, there will be table three and table 6(farthest from the heater) with cloth you can scoot a little if you try.
If the cloth(NOT FELT!!) installer just went by what has worked in the past, he may not be used to those conditions, therefore it isnt his Fault. A good mechanic, however, will fix it for you at little or no cost, in exchange for the knowledge he has gained. jkh