01-24-2010, 07:43 PM
The idea of useing a vapour barrier in the first place is to keep the insulation dry and stop moisture tranfer through the walls to the outside .I know what you have there people wont be having showers or cooking and no moisture vapours to contend with .What your not looking at is the cold concrete floor and the warm air near the roof.Somewhere in between you will get moisture .I guess your in Texas and you still have hot humid days .Its still water vapour and Im sure you havnt seen it in houses there but with your floor you might have a problem.Im up in Ontario and where minimum code is 6 mil poly and that keeps the moisture in .Were as outside its housewrap or what is called Typar .Something that lets the insulation breath and keeps it dry. You can get a nasty zap off a humid rail when you cant see it .I know code is different all over .Just looking out for the other guy I guess .Goodluck and I will watch this thread to the end.Like you said ,Keep them trains dry. MartyG