Marcel/Jeffrey: Vapour barrier under the slab? I’m not clear. Are you meaning a moisture barrier like you would have at the exterior of the walls, under the concrete slab?
you guys are great! thx a million
Yes, moisture barriers are required under the slabs, prefferably 6 mil or more with taped joints everywhere to keep the moisture from migrating in the space.
The ridgid foam on the concrete foundation does the same thing. Since there is no air space for condensation to develope, the moisture stays in the wall. Moisture is from the earth which is at 54 degrees +/- year round.
The air space in that location in a heated basement mixes with the heat loss and a dew point is reach and condensation occurs.
In an exterior wall, the envelope dries to the exterior and the dew point is behind the sheathing hopefully. 
I think we’re talking about two things Marcel. A moisture barrier that prevents water intrusion and a vapour barrier that prevents internal “saturation”. I think that when Jeffrey said the “vapour barrier should be under the slab”, I’d call that the moisture barrier. Could also be that I’m suffering from brainfartisis. But I do get the point regardless. Cheers.
Let’s not forget about the Canada/US “language barrier”. 
Is Visqueen the same as PolyE. ??:)
How to speak Canadian. Repeat the following words. (Applies to Atlantic Canada, and coastal Maine too I’d imagine, lol)
1.Whale
2.Oil
3.Beef
4.Hooked
Now, say them really fast and slurred together!
LOL, is this like Hoover VS Vacuum or
Marley roof VS cement roof tile???
No, more like Canadian and US.
Mark, I am American Acadian French born on the Canadian Border of Maine. 
That is why a moisture barrier is the same as a vapor barrier. :mrgreen:
Good illustration Jeff, exactly what I was trying to explain.
Yeah thats a nice graphic
That mold that formed on the concrete foundation wall under the fiberglas…what is the food source? I didn’t think glass or concrete was a suitable food source for mold.
Dust
Agreed. Dust.
The ground temperature 2 M deep drops as you move North. In Edmonton the mean temperature is 6C. I guess where M Cyr the temp is 12 C (54F).
When room temp is at 20C and the humidity is 40% and the temperature drops you get condensation between 5C and 6C, the dew point. Thus if the 20C with 40% RH temperature drops below 5C you get condensation at that point (Dew Point or 100% RH). It is imperative that the vapour barrier is 100% sealed to stop warm moist interior air leaking into the wall space where the temperature drops below the dew point. The NBC calls for a 100% vapour barrier on the warm in winter side of all exterior surfaces. The NBC also calls for a water proof barrier under slabs on grade.
I did not see any vapour barrier in the posted photos and that is the problem.
Also 99.9% of the houses I’ve inspected over the last ten years that have insulated basements do not have sealed vapour barriers between the floor joists. The newer house have polyethylene vapour barriers but they are not sealed and leak.
For those that do not know RH (Relative Humidity) is the percentage of water vapour the air can hold at that temperature.
Vern, you left your Wednesday night poker game to explain this?
Anything for the cause!
Vern, there are some that suggest a basement be finished/constructed with the reverse in mind. That is to say build with no vapour barrier at the warm side of exterior walls. As moisture levels in the concrete are relatively high the lack of a vapour barrier allows the wall cavity to draw and expel moisture from the foundation to the interior where a humidifer can capture it. I’d appreciate your thoughts.
Give him a minute Mark, he’s holding a pair of jacks.