How can I prevent water buildup btwn vinyl chair mat & heated floor?

In my home office, an office chair sits on a 2 mm vinyl chair mat. The mat sits on heated terra cotta tile. Water accumulates between the floor mat and the tile. What solutions to this water issue exist and what damage is the accumulation likely to cause.Installation was as follows: Over an 87-year old existing six-eight inch slab (the vapor barrier for which is unknown and cannot be changed) we poured an additional six inch slab, which, after a 6-8 week cure period, was covered with an electric heat mat, 1/4-1/2 inch of self-leveling concrete, standard thin set and 1-1/2 centimeter thick sealed terracotta tile. Today the temperature-relative humidity inside the office are 70º-47%; the outside temperature-relative humidity are 53º-86%. A 12-inch split stone wall surrounds the old, original floor slab and the crawl-space adjacent to the slab floor is completely dry.

  3 answers
Your comment...