The VCT laid in our community hall started gapping severely after just a month. It appeared the tiles were moving back towards the wall taking up the space that had been deliberately left to allow for expansion. How much does the outside weather and temperature play in this? During the 4 day period laying the new plywood subfloor and then gluing the tiles the temps., dew point temps. and relative humidity were high! At some hours the humidex was in the mid to high 90s F. (30s C.)