Originally Posted by
Mel Fulks
James ,the word BARRIER is a little stronger but not an absolute term . Nets are barriers but some fish go through them. And I don't believe anyone is dumb enough to think that "vapor barrier" meant no vapor was going to get through. Professionals applied the term ,it was not a secretarial mistake. They chose the term and now we are making a mistake in useing it !? I think they have backed off in view of how AC is used and to push more expensive products.
Mel, there was confusion among the trades, professionals and the consumer market with the initial use of the word barrier applied to broad market of products in turn causing moisture issues in many homes. The change clarified in the 2009 ICC presented classification to help people understand and apply these products correctly based on a perm rating. So, it wasn't a matter of people being stupid, but a failure to understand building science in a rush to make homes more efficient, it's more than the semantics of words.
"The real voyage of discovery consists not in seeking new landscapes, but in having new eyes." - Proust