I bought a cabin on a steep slope with a mostly unfinished basement 3 1/2 years ago to use in winter. The back wall is mostly foundation and the front is walk out. It had a perimeter/french type drain in at type of purchase and the basement was dry. It was also dry the next winter. Last year was a very wet year and when I returned in fall, it was a little musty. This year, definitely musty. I'd made a mistake and put some boxes on floor and they had mold on bottom. Also some light mildew/mold on a couple pieces of furniture, but none on sheetrock or concrete walls.

I'd like to finish the front of the basement but am concerned about the moisture as I'm allergic to some molds. One contractor said if I leave heat/air on when I'm gone (4-5 mos) it should take care of it.

The other wants to use dam-tite on all concrete-pricey! I have gutters with downspouts away from foundation.

Any opinions?

Also, one gave me an estimate of 30,000 to finish walls and put in shower bath. That seems steep since sheet rock is on outer wall but needs taping. There is also ducting in place for heat and it's been partially plumbed. I would finish about 600 sq feet but except for closet and bath and walling off the back for storage, it'll be open. What would be reasonable for middle of road finish.