Rigid foam over a stud wall filled with closed cell foam
user-3064971
| Posted in Energy, Heating & Insulation on
Given a stud wall with OSB sheathing and filled with closed cell foam and northern climate; is it OK to put rigid foam on top of the sheathing in order to minimize thermal bridging? Since the closed cell foam acts as a moisture barrier from inside the house, the inside of the OSB should not have any condensation problems even if is below the dew point. Right?? The only moisture the OSB should see is from the exterior. Right??
Replies
Howdy, The dew pint concern
Howdy, The dew point concern is valid be sure if adding exterior foam to add at least 2" making the dew point in the foam not the OSB is your goal. What type of foam is in the stud wall? Open or closed and its weight? Try an find out as that information will influence your decission. Moisture vapor can penatrate any break in the foam any gap any holes put into it.. So with foam on both sides of the OSB how will it ever dry if it gets wet? Pipes break, windows break water gets in walls . I believe that is why foam is not added to both sides of OSB so one side can allow the moisture to dry out ...