Floors above Crawl Spaces: Reducing the Risk of Moisture Accumulation within Wood Floor Assemblies for Residential Buildings in Hot-Humid Climates (TechNote)

This TechNote provides design recommendations to reduce the risk of moisture accumulation within wood floors above crawlspaces in hot-humid climates. The factors that affect moisture accumulation include season, indoor temperature, types of floor insulation and floor covering, and type of crawl space. The focus of this TechNote is selecting floor insulation and coverings to control moisture migration and allow drying, should the floor get wet, for vented and open crawl spaces.

TechNotes: Best Practices for Home Builders
In recent years, building codes for energy efficiency and related standards have been amended to require greater amounts of insulation in exterior wall and roof assemblies, including continuous insulation on exterior walls, higher levels of building air tightness, and mechanical ventilation.
NAHB’s Construction Technology Research Subcommittee worked with Home Innovation Research Lab to develop these TechNotes to help builders navigate these new code requirements and implement best practices to avoid building performance issues related to interior humidity levels, condensation in wall and roof assemblies, and interior air quality.