lastlight's 404

[MitchM]

Insulating basements is tricky because the concrete wall is a source of moisture as well.
The lower part of the foundation wall that is in contact with outside soil will always be a source of moisture unless the foundation has been waterproofed. The upper exposed part of the same foundation wall will be a place where the moisture can escape.
Vapour barrier should be on both sides of the insulation for basement walls, with an area at the top of the foundation-side vapour barrier left so the insulation is only exposed to the "drier" portion of the foundation wall.