Can you use Foam boards on basement walls to stop condensation?

Chad Johnson
Updated: Sept. 4, 2020

I am finishing my basement and my basement exterior walls are fully framed about 2” away from the concrete.  They have mineral wool in between the stud bays but not all dry walled yet. My issue is that since insulation was added on one of the walls (all others checked and fine) condensation is building up after I waited a month or so into winter and pulled the insulation out to check. This particular wall is not buried fully like the rest (due to slope of property) and it is exposed to the outside temps top to bottom from the outside so I know this is why this is occurring only here.

My question is now that it is after the fact how can I correct this condensation issue?  If I install 1” or 2” foam insulation board sliding them in behind the studs and directly to the concrete wall will this stop the condensation or will it just build up on the inside of the foam board and still be a problem?

Hoping to just be able to apply foam to regulate the concrete temps and prevent inside warmer air from touching the concrete and condensating...but wanted to get opinions prior to spending $300.


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