I laid 1/2' plywood as a new substraight over my old 3/4" t&g plank subfloor. The finished floor will be carpet. I left about an 1/8" gap between sheets. I later noticed that my helper friends were a bit liberal with the 1/8" gap theory in a few spots. I was wondering if filling all the gaps with something flexible like 100% silicone would be ok? Would it still allow proper expansion? Or would the silicone bead want to get pushed up and out of the gap, or completely defeat the purpose of leaving the gaps?
Thanks for any thoughts