It's true that too much of a good thing can be a bad thing, and insulation is no exception. While insulation is an important part of keeping your home comfortable and energy-efficient, there comes a point where excessive insulation can start to have a negative effect financially, environmentally, and in terms of the longevity of your home. So yes, it's possible to over-insulate your home. However, it's important to note that too much insulation isn't the problem.
The issue arises when the insulating material blocks the ventilation grilles. This can prevent fresh air from entering the attic, leading to condensation, moisture-related problems, wood rot, and mold. When it comes to insulation, there are several R values available depending on the space you're looking to fill. For example, R-13 insulation is usually used for walls with 2-by-4 uprights, R-19 for walls with 2-by-6 uprights, and R-30 for ceilings and floors with 2-by-10 beams.
Some manufacturers also offer specially processed high-density block insulators to provide high insulation properties in a smaller space. It's important to remember that higher R values will not be achieved if more insulation is introduced into a space for which that valuable insulation has not been designed. Additionally, since insulation works on the surface, getting it wet can be problematic. Avoid placing the insulation in a place where moisture can accumulate, as this can cause the surface of the insulation to shrink and stay that way.
If you're dealing with damp basement walls, do not use insulating blocks - they will not protect you effectively and could become an ideal breeding ground for mold and mildew. In such cases, try to fix the water problem and use rigid foam-based insulation instead.
