Seeing slab foundations on new construction homes in the South gives me hope for the future. Some builders are adapting to new, more efficient ways of ensuring we don’t simply invite the dreaded humidity and moisture directly underneath your living area when it is hot and humid 6+ months out of the year. Crawl space foundations contain about half of the basis for potential issues that we diagnose in homes in Arkansas. Bulk water, cupping hardwood floors, foul smells, rodent and pest infiltration and overall high bills (from constantly running the air conditioner to get the high humidity levels down) are just some of the major complaints that stem from the crawl space.
Many crawl spaces in Arkansas have fiberglass batt insulation under the floors, if any at all. I’ve had discussions with customers about how building science is teaching us that moving away from crawl space foundations. Building on slabs is ideal from an energy efficiency standpoint. Customers that experience cold floors in the Winter, and high inside humidity in the Summer, will usually be great candidates for upgrading the insulation from the crawl space. Most fiberglass batt insulation I see in these spaces are all at varying levels of degradation. This depends on a few factors. One variable is the amount of air being allowed in, through foundation vents and open or missing crawl space hatches. Foundation slope also plays a large role in crawlspace conditions in Central Arkansas. Homes built on hilly terrain which drains well may not experience much bulk water. In these situations, the condensation on fiberglass batts might be minimal, but it will still become an issue over time.
Spray foam insulation, both open and closed cell, has greater functionality than fiberglass batts. Closed cell spray foam will help to insulate the floors from the crawlspace, and also creates an air seal. This helps to mitigate rising humidity inside the home, as well as any foul odors that usually emanate from the open crawlspace. This option is ideal, especially when it is obvious that existing insulation is degraded. Even though encapsulation is amore ideal approach, it is not always financially viable to many customers living in older homes that, more often than not, have crawl space foundations rather than newer homes with slabs.
Written by: Adam Davenport