Hi everyone, I've been trying to solve a high humidity problem with my newly purchased cottage. Briefly, a 1920's cottage with addition in the mid 60's. 3 season not insulated except for 2" styrofoam over top pine planks and siding on top level. Bottom floor (basement) was dirt. Walls are small footing with cement block up to 3' in height. I excavated the floor and put in a new concrete slab on 4" clear stone with drainage pipe around perimeter (inside and outside) I laid down a foil barrier and tuck taped joints. Poured roughly 4" cement. Exterior walls were changed for osb, added layer of bat insulation (r20), vapour barrier and finished interior walls with osb. Outside I sloped the ground away from cottage as much as possible, added drain pipe and clear stone, where i could I put tar and 2" styrofoam insulation. I have only one vent 6"x 10" roughly inside the basement. At this time my humidity level is close to 95% and temp is around plus 2 celcius. I realize new walls and a fresh floor will emit alot of moisture into the air but how could I keep the humidity level to the 50% or lower level that I am looking for. I have one space heater down there to keep temps above freezing but all it serves to do is create even more moisture. Does anyone have an idea how to bring my humidity level down without having to keep baseboard heaters running 24-7? Here are a couple pictures if I'm allowed to post them.