In response to questions on your show you have told your listeners that at the foundation wall, the insulation should come down to 8 inches from the floor and the vapour barrier two inches below that. Why is that space required and if it is to prevent condensation, how does it to that? Then, how is the drywall protected from condesation or humidity and eventually mildew? What would happen if the vapour barrier was brought down to the floor and sealed like the rest?
Answer:
My system has always taken for granted that where there is no vapour barrier, there might as well not be insulation as far as below grade is concerned. I could not tell you why the system stops condensation but I know it does - I'm a handyman and not a scientist. I have never experienced a problem with the drywall having to be protected in the past (other than from an actual flood) so I haven't paid attention to it.
Courtesy of Ren Molnar, Construction Consultant at HomeFocus.com. I can also be reached at (613) 748-3003 and Home Focus phone-in is broadcast live 8 to 10 A.M. (Ottawa, Ont. time) on Saturdays on www.cfra.com.