I am about to undertake finishing my basement. I have decided to use Delta-FL for the flooring. For those not familiar, it is a dimpled High Density Polypropolene sheeting. The Delt-FL is laid down first, then 5/8 tongue and groove plywood. (See image or following link for more detail http://www.doerken.de/bvf/ca-en/prod...L.php?navid=18)

What I was considering was putting down the Delta-FL first leaving a one inch gap between it and the foundation walls. I would then bring the vapour barrier down from the back side of the perimeter wall studs at outside ground level down and around the stud wall and back up to the ceiling. I would seal the vapour barrier to Delta-FL with sealing tape at the base plate on the inside to the Delta-FL, and seal the vapour barrier at the ceiling. The vapour barrier on the back side of the perimeter stud walls would not run up to the top of the walls. There would be about a 24" area of exposed vertical stud length.

I would then lay down my 5/8 tongue and groove plywood, and then install small vents along the top of the foundation directly to the outside. I was considering every 10 to 12 feet or so. I thought this way, I would get substantial air flow behind the finished walls and even under the Delta-FL. I would be concerned about heat loss in the winter, however, I believe this way would maintain as to a humidity free environment inside as possible.

Suggestions or opinions about this system? Also, how much expansion gap should I leave between the perimeter walls and the plywood?

Thanks.

skiberger

Never seen the system but it sounds/looks good. You shouldnt loose any heat if you insulate the stud walls.

johnveilleux

Thanks for your answer. I contacted the manufacturer, and they recommended against it. Back to the drawing board........