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Crawl space vapor barrier or not?


we live just next to the canal, several hundred feet from the sea-edge in North-East. House have been built in early sixties. There is no basement but 3-4 feet tall crawl space underneath the whole building. Crawl space/foundations are built of cinder block. Crawl space is vented in the usual manner (two vents). Surface is sand and there is no vapor barrier.

We have received conflicting suggestions from the house inspector and the people (some of which by occupation should be experts on this) who live in the similar houses in the area.

Question is should we install vapor barrier (essentially a heavy duty plastic over the sand) or not? Pro-proponents argue that the barrier will keep house drier overall. Against-proponents argue that the area will dry faster without the barrier and that for our location that is the more important issue. Also, drainage could be impeded in the rare but existing occasions (storms at the level equivalent of the weak hurricane) when the sea rises above the docks and brings few inches of seawater into the crawlspace (our worst experience was heavy north-easter that have brought about 3-4 inches of flooding for about 10-12 hrs).

So, should we or should we not do vapor barrier?

Dusan Maletic

PS Yes, if hurricane of category 2 comes by, our flood insurer will not be happy... This question centers on the lesser magnitude events...

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