We all make mistakes (including me) but I would hardly characterize Lsiturbrek as 'the most respected and studied man in the country' in this matter since his advice conflicts with most all building codes for vapor barriers and proper basement contruction across the US. (maybe Piffin is in Canada?)
But after Domino's great handling of the vapor issues in a basement (with some disagreement) I thought I'd give my 2 cents toward his last response yet again:
First, vapor flow into a basement is from 2 sources:
One is from the wet ground into the basement thru the foundation...
The other is from the living space thru the framed wall toward the foundation.
Without addressing BOTH these directions of vapor flow we are all talking passed one another.
VAPOR FLOW IN THRU THE FOUNDATION:
Vapor flow in from the soil, thru the foundation, occurs despite any temperature differentials, because the the soil outside the foundation is always generally "wetter" with more water vapor than the interior of the basement under most all conditions even when the soil vapor temperature is colder.
This means that even despite 'damproofing' of the foundation and basement temperatures being warmer, water vapor migration will be from areas of great concentration to areas of lesser concentration.
So the first major point of vapor transmission worry is at the foundation itself.
Without saying, the very best method(s) to prevent liquid and gaseous water transmission into a basement are from the outside.
Given that in most cases this cannot be done, the next best method is to deal with vapor and liquid water immediately at the foundation wall as soon as it enters the basement.
One acceptable method is to allow the water vapor to enter the foundation unabated and then deal with it from there.
This can be accomplished by the wholly acceptable technique of applying a 6mil polyethylene sheet over the foundation walls SO LONG AS this polyethylene sheet continues below the slab and footer or into a peripheral drain system so that any condensed water will not collect or pool in the basement.
Terminating the poly sheet above the slab does no good, since any vapor from without will only condense on the poly sheet and trickle down in pools on top of the slab.
This is also the drawback of using rigid foam panels directly over the foundation.
While rigid foam panels can decrease the potential for interior warm, moist air migrating outward from reaching colder masonry surfaces and then condensing (and let us not forget that the major proponents of these products are the rigid foam manufacturers themselves)...the use of rigid foam masonry panels alone does not prohibit gaseous water from without migrating inward and does not prevent this vapor from condensing between the foundation on the rigid foam and thus also trickling downward and pooling.
SO THE FIRST AND BEST ORDER OF BUSINESS IS TO ELIMINATE GASEOUS WATER/WATER VAPOR FROM ENTERING THE BASEMENT FROM THE OUTSIDE IN IN THE FIRST PLACE.
Rigid foam cannot accomplish this, but water and vapor proofing coatings on the inside of the foundation can.
By coating the inside surface of the foundation with a vapor and waterproofing paint, you achieve the very BEST of all possible foundation condensation preventions by never allowing outside vapor from collecting in the basement in the first place. A MUCH BETTER SOLUTION THAN USING FOAM PANELS.
You can STILL use foam panels in conjunction with a vapor proof coating, but foam panels should not be used alone.
VAPOR MOVEMENT IN FRAMED WALLS:
Domino gave a very good explanation of how warmer (usually) moisture interior air from the living space will want to migrate out thru any framed walls and why a plastic sheet should NEVER be hung in a framed wall in a basement to prevent this migration.
The fact is, that warm interior air will want to migrate out toward the foundation walls in some situations and yet in other wish to migrate in from the outside in others.
Placing a plastic sheet in a framed wall never makes sense in a basement precisely for those reasons.
And while placement of rigid foam panels directly over the foundation walls will prevent condensation of water flowing outward by 'warming' the foundation surface, using foam panels without also vapor proofing the surface beneath only meets half the problem.
I have no idea where Lstirbrek gets his ideas since they violate all know acceptable building practice and code requirement for basements.
Unless his research affects certain locations it makes no sense for most of the US.
(And I will gladly be proven wrong)
But getting back to and addressing Domino's original question about placing 'fanfold' on the foundation then framing to it....
Unless you also water and vapor proof the foundation beneath the rigid foam beforehand....
AND unless you also install a kraft paper facing in the basement wall studs in front of the foundtaion walls...
AND unless you keep the framing at least an inch or two away from the foundation wall including the rigid foam...
It should not be done and may violate your State's building code.
As for Piffin, if you think I have handled you or your argument cheaply or worngly and did not offer you a fair shake...I will apologize in advance and still request further correction.
I do not consider this forum an arena by which any of us should disembowel the other for the public's pleasure.
I participate to be educated in as much as I strive to educate and if we all draw blood along the way, so be it.
Please, however, do not take my own personality quirks or disagreements as anything personal.
I'm an emotional, zealous type of guy and not fond of being proven wrong...but equally zealous and emotional for the truth when I am...
Respectfully submitted to Piffin, Domino and anyone else who wanders in...
And if you can enlighten me on Lsturbrek, I'll be glad.