Basement walls should be insulated with non-water sensitive insulation that prevents interior air from contacting cold basement surfaces—the concrete structural elements and the rim joist framing. Allowing interior air to touch cold surfaces will cause condensation and wetting, rather than the desired drying. The structural elements of below grade walls are cold especially when insulated on the interior. One of the greatest concerns are rim joist areas—which are cold not only during the summer but also during the winter. This is why it is important that interior insulation assemblies be constructed as airtight as possible.
In most basement wall situations, the foam plastic insulation material will need to be covered by a fire/ignition barrier. ½” gypsum board usually provides sufficient ignition barrier. When this ignition barrier is supported on a stud wall, the cavities of this wall may be filled with supplemental insulation. It is important that the airtight foam insulation assembly be continuous behind the framed wall. No interior vapor barriers should be installed in order to permit inward drying.
yes, to keep the moisture to a minium, to prevent mold
Yes you should use a vapor barrier when doing a basement finishing project.
yes you should, i would use it
Yes, but you should always use an anti-microbial type of vapor barrier to prevent mold & mildew growth behind your walls.
Always , 6 mil plastic barrier is great ,keep the jobsite contact away from concrete as much as you can
yes