Here’s a picture of what Supernova74 is talking about.
Attachment 81263
Bucko my plan is to use construction adhesive vertically every 4-6 inches on this product.
I used the same product and technique only thicker to insulate the exterior of my heated garage foundation. The vertical use of adhesive allows for any trapped moisture to run out.
“Owens Corning[emoji2400] FOAMULAR[emoji2400] extruded polystyrene (XPS) insulation a closed-cell, moisture-resistant rigid foam board with excellent long-term stable insulating performance and durability.”