We have enclosed crawl space under our cottage. Cottage does not have foundations per say but has piers every few feet on which structure has been build. On the perimeter there is a concrete wall around the cottage is around foot high which just lies on the ground.

I recently started monitoring humidity and it can go up to 70% which I assume is a bit too high. There is no standing water in the crawl space but one spot can be moist after rain.

Inside the cottage is around 55%-60% which is pretty normal for the cottages in the area. We are located 30 feet from a lake.

Two questions:

1) Would installing french drain in front of the cottage (around 10 feet in front of it) provide any moisture control ? I feel it may only contain surface level water which would be minimal. Cottage has proper eaves and downspouts.

2) Are there any disadvantages of installing vapor barrier. The only would issue would be height, its between 3-4 feet in some areas maybe even 2.