Spray foam insulation is often used to help prevent moisture problems and preserve a home from such problems. However, the misuse of spray foam insulation can cause more moisture problems than regular insulation. This has occurred across the United States as insulators have attempted to use spray foam insulation in cavities to promote air sealing, while using other insulation products in order to conserve on the cost of using this type of insulation. Spray foam insulation must be installed properly in order to avoid these issues and certain combination system applications must be avoided.
Open Cell Spray Foam Insulation
Open cell spray foam insulation offers excellent air sealing along with an R-3.5 per inch that equals the R-value per inch of standard fiberglass insulation. The air sealing ability of this product makes it a much more superior insulation material than fiberglass. The one issue with open cell spray foam is that the cells that make up the foam are open, allowing the insulation to absorb moisture.
Unfortunately, this type of insulation was not required to have a vapor barrier until moisture issues were discovered. The vapor barrier that needs to be applied is an electrometric coating vapor barrier that is applied over the foam like paint. This coating prevents the moisture from wicking through the insulation onto the drywall where it can cause mold and mildew issues. This type of insulation is susceptible to moisture containment because of its open cell nature. For this reason, it is not used often in climates with high humidity or significant temperature variances between seasons.
Closed Cell Spray Foam
Unlike open cell spray foam, the cells are closed making them almost completely waterproof. Where moisture issues happen with this type of spray foam is when it is used in conjunction with other insulations in layers that are not thick enough to prevent the dew point from allowing condensation to foam inside the framing cavities of a home.
A common application with spray foam by insulation companies was called flash n’ batt, which involved applying about ½ to 1 inch of closed cell spray foam and then laying a fiberglass batt over the spray foam. With the forming of condensation in the cavity and the spray foam sealing out any air movement, the condensation cannot escape and causes significant moisture damage in a very short amount of time. This practice can only be performed if a minimum of 2 inches of closed cell spray foam is used and then the fiberglass batt is placed in the cavity. This prevents the thermal convection that causes these types of moisture issues.
While spray foam insulation is a great product, the improper application of this material can devastate a home’s integrity and cause serious health issues to those who live in a home with these insulation systems. If you have moisture issues in your home and you have on of the above types of insulation systems, you will need to contact the contractors responsible to fix the issues as fixing this type of problem is a very extensive process that requires the removal of all the drywall.
Adam Yeomans - Adam Yeomans has been writing Internet content for just over a year for the purpose of informing people on how to properly complete home ...
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