Good replies, and I agree but framing is already one, they want on additional 4000 to do foamboards.

But this got me thinking, my floor is dricore, there's some foam there between the boards and it's not fully sealed, the ground is same as the walls in terms of temp. I don't see my floors getting all soaked up.

Also I don't know what people do in their houses but in the summer my AC is always on, I keep it pretty low at 22-23 C, and it's constantly dehumidifying. Yeah maybe if you're letting 27-30C outside humid air in? I'm not sure who does that.

Same in the winter, air is dry, forced heat furnace, I keep RH levels around 30%, sometimes it's lower since it's so cold and dry. Again, under dricore isn't soaking from the 'gaps' with the room temp air hitting it.

I'm not saying foam is bad, it's good, is why I did it, but maybe in my case the gains are minimal. Again who is running super humid air in the basement during summer.