Research results indicate that a sealed crawl space is a great moisture control strategy with impressive energy saving potential, as reported by Advanced Energy.
As opposed to what many building scientists believed years ago, new research has shown that vented crawl spaces create the perfect environment for mold growth, wood rot, insects and moisture problems.
A sealed crawl space is the perfect defense against these detriments, and has proven to also create a healthier living environment and reduce energy costs.
This Bruington, VA client contacted us about repairing moisture damage in their crawl space. Moisture had caused mold and mildew growth, was absorbed in the insulation which held it against the floor joists, the material began to delaminate and fall away from the floor.
All debris and insulation was removed from the crawl space, microbial growth was treated, the vents, sill plate, & rim band were sealed, the foundation walls were insulated with closed cell spray foam insulation and a dehumidifier was installed to control the relative humidity. The homeowners no longer need to worry about moisture damage in their crawl space and have the added benefit of warmer floors in the winter and reduced drafts in the home.
We met this homeowner at a home show, where they asked us to come to inspect their crawl space because they were interested in encapsulating it due to moisture and mildew-mold concerns. This section of the crawl space is under an addition. The vapor barrier is unsealed, allowing moisture to rise from the ground and contribute to high relative humidity. Microbial growth is beginning on the floor joists and the fiberglass insulation is beginning to sag and fall.
The old materials have been removed, vents sealed, and the sill plate and rim band have been sealed as well. The CleanSpace vapor barrier has been installed with all seams overlapped and sealed. The moisture barrier is also run up the walls 6-8 inches above outside grade. The walls are prepped for spray foam insulation to be applied.
As the insulation acts as a sponge, it holds moisture against the wood joists raising the moisture content of the joists. Mold requires organic material, warm temperatures, and relative humidity above 60% to grow. Often we see mold growing on the paper backing of the insulation and on wood joists in the crawl space. As the moisture content in the joists increases, the probability for wood rot becomes more likely. Once the joists reach 19% moisture wood rot begins. An antimicrobial called Shockwave is sprayed onto the joists to kill the mold. Once the encapsulation is complete and the dehumidifier is installed it will be set to turn on before the humidity in the crawl space reaches 60% (The ideal point for mold to grow). The Encapsulation system will help prevent ideal conditions for mold to grow from occurring and make the home healthier and more comfortable.
Since the natural airflow in a home is from bottom to top, the air that is circulated back into the home from the sealed crawl space will be clean, dry air, creating a healthier environment.
Additionally, the air circulating back into the home is now conditioned air, reducing the need to heat or cool it, resulting in lower energy costs.