Crawlspace Ventilation

When most property owners think about ventilation upgrades, they often consider installing new windows and doors or replacing the existing HVAC equipment. However, they often forget to consider one of the most important locations within their building: the crawlspace. Improper ventilation can allow for humid air to become stagnant within the crawlspace, spurring microbial growth and accelerating the deterioration of both wood and concrete structural elements. Given the difficulty accessing the crawlspace, as well as the typical space restrictions, crawlspace structural repairs can be quite costly and lengthy, but proper ventilation upgrades can help curtail these repairs.

Allowing for adequate airflow is crucial for ensuring the longevity of the crawlspace structural elements. The International Building Code (IBC) imposes certain ventilation requirements given the size of the crawlspace area and other circumstances, such as climate conditions and crawlspace construction. In our experience, it’s not uncommon to find crawlspaces with either undersized vent openings or simply too few openings at all. Additionally, we typically find vents that have been covered with mulch or other landscaping, rendering the vent useless. The number of required vents can be reduced through the installation of fans within the foundation walls or the installation of a vapor barrier over the exposed crawlspace soils, given that the vapor barrier made of qualifying materials, properly installed, and in good condition. If you’re overdue for a crawlspace inspection, reach out to ETC to help evaluate your crawlspace today.