Basement insulation is far more complicated than insulating regular wood framed walls. In fact, improperly insulated basement walls are one of the biggest reasons for mold in homes. If you don’t do this correctly you’ll be exposing your family to dangerous mold exposure.
It’s All About Water Vapor
Basement Insulation is difficult to understand because of water vapor issues. While this is a topic best left to another article entirely, it’s important to realize that there are two sources of significant water vapor in a basement. Just like in the rooms above the basement, water vapor from inside the room wants to escape to the outside.
In addition, and likely more serious, is water vapor escaping from the concrete wall and trying to escape to inside the finished room. Concrete looks just like a sponge under a microscope and it holds water just like a sponge. In fact, over the entire life of concrete it holds water. So concrete is ALWAYS letting off water vapor and that water vapor is trying to either dry to the outside or into your finished space.