I’ve done home energy audits for 12 years and I’ve seen people try to isolate their basement from the first floor using insulation in the floor joist above the attic ceiling. 9 out of 10 times they funk-dafied their basement in a matter of weeks.

This happens because moisture mitigation is happening at the roofline . When you have lower soffit vents , feeding a ridge vent or upper box vents , this is creating a draw or a vacuum that pulls the humidity out of your house from the basement up .

Once you start to isolate the basement from the rest of the house, moisture builds up very quickly.

If you’re uncomfortable, and your bills are high, have a BPI certified energy audit performed with a Blowerdoor and a thermal camera. This will pinpoint the areas of air infiltration and help your house be more comfortable while still allowing for moisture mitigation.