Avoiding Potential Moisture Problems with Rigid Insulation Avoiding Potential Moisture Problems with Rigid Insulation
Rigid insulation is used in place of fiberglass rolls and blown-in insulation because it is relatively cheap, easy to install and has many features built into it. Rigid insulation is not perfect—no insulation is—and moisture can sometimes become an issue. Moisture can cause your heating and cooling system to work harder than it has too, but it can also cause prime conditions for the growth of mold. There are things that you can do to enhance the effectiveness of your rigid insulation to prevent moisture from becoming a problem.
Directly to the Wall
Rigid insulation comes in many varieties, but all are highly resistant to moisture. In attics and basements, the moisture problem typically appears directly on the surface of the wood or the concrete. This moisture can drip between the walls or on the floor. The rigid insulation simply will not be very effective if this is the case. The one solution you can use is to attach the rigid insulation directly to the wall. This prevents the moisture from even forming as the insulation will repel or absorb it.
Moisture inside the home is often caused by condensation. The cold from the outside interacts with the heat on the inside and water forms. This is the same thing that happens when you get a glass of ice water and place it on the counter. If you have water pipes in the walls that the insulation is covering, then the pipes can still form condensation regardless of how good the insulation is. To prevent this from being an issue, always cover the pipes with their own insulation. They create pipe wraps specifically for this purpose.
It is not always feasible to attach the rigid insulation directly to a wall, so your only other recourse is to use a vapor barrier. These come in several styles with different additives, but when you get right down to the heart of them, they are merely plastic sheets.
Place the vapor barrier on both sides of the wall, making sure it extends past the joists and beams. After you install the insulation, you can add another layer of vapor barrier if you so choose.
These are also known as reflective foil. Essentially they help to even out the temperature by reflecting the heat and cold. Once those elements are controlled, moisture simply will not form—or, if it manages to do so, it will not be sufficient enough to cause an issue. The reflective sheets are placed directly on top of the rigid insulation.
The Right Insulation
All rigid insulation is created to prevent moisture from being an issue, but some are better than others. Stay away from fiberglass insulation and concentrate on polystyrene instead. It may cost a little more money, but will be more effective. The thickness of the rigid insulation also counts, with a 2-inch thick polystyrene rigid insulation being the best course of action for harsh situations.